- Photoinduced Regioselective Olefination of Arenes at Proximal and Distal Sites
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The Fujiwara-Moritani reaction has had a profound contribution in the emergence of contemporary C-H activation protocols. Despite the applicability of the traditional approach in different fields, the associated reactivity and regioselectivity issues had
- Ali, Wajid,Anjana, S. S.,Bhattacharya, Trisha,Chandrashekar, Hediyala B.,Goswami, Nupur,Guin, Srimanta,Maiti, Debabrata,Panda, Sanjib,Prakash, Gaurav,Saha, Argha,Sasmal, Sheuli,Sinha, Soumya Kumar
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p. 1929 - 1940
(2022/02/01)
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- Iron-catalyzed domino decarboxylation-oxidation of α,β-unsaturated carboxylic acids enabled aldehyde C-H methylation
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A practical and general iron-catalyzed domino decarboxylation-oxidation of α,β-unsaturated carboxylic acids enabling aldehyde C-H methylation for the synthesis of methyl ketones has been developed. This mild, operationally simple method uses ambient air as the sole oxidant and tolerates sensitive functional groups for the late-stage functionalization of complex natural-product-derived and polyfunctionalized molecules.
- Gong, Pei-Xue,Xu, Fangning,Cheng, Lu,Gong, Xu,Zhang, Jie,Gu, Wei-Jin,Han, Wei
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supporting information
p. 5905 - 5908
(2021/06/18)
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- Novel ester derivative of cinnamates with different long alkoxy chain: synthesis, mesomorphic properties, biological evaluation
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A novel series of liquid crystals involving cinnamate-based mesogenic units interlinked between aromatic ester and alkyl bromide were designed and synthesized. All target molecules were confirmed by IR, 1H NMR, 13C NMR, ESI-MS, and elemental analysis. The mesomorphic behavior of novel synthesized materials (P1–P18), (V1–V18), and (M1–M18) was investigated through a polarizing optical microscope, differential scanning calorimetry, and thermogravimetric analysis (TGA) analysis. The lower carbon chain substituted member showed nematic phase while compound possess higher carbon chain exhibited only SmC phase. Thermal stability is determined by TGA analysis. All the cinnamate derivatives were screened for their anti-microbial, anti-malarial, and anti-tuberculosis potency. Among them, most of the derivatives exhibited outstanding anti-bacterial and anti-tuberculosis activity. Some derivatives also exhibited potent anti-fungal activity.
- Bhalodiya, Pradip C.,Patel, Hemant N.,Parmar, Tejasvi H.,Sangani, Chetan B.,Rajani, Dhanji P.
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- Acylated pelargonidin and cyanidin 3-sambubiosides from the flowers of Aeschynanthus species and cultivars
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Thirteen anthocyanins were isolated from the flowers of two Aeschynanthus species, A. fulgens and A. pulcher, and six cultivars, ‘Mahligai’, ‘Mona Lisa’, ‘SoeKa’, ‘Redona’, ‘Freshya’ and ‘Bravera’, and identified as pelargonidin and cyanidin 3-O-sambubiosides and their malonates, succinates, p-coumarates and caffeates, and pelargonidin 3-O-glucoside by acid hydrolysis, HR-MS and NMR. Of their anthocyanins, pelargonidin 3-O-[xylosyl-(1 → 2)-(6''-malonylglucoside)] (2), pelargonidin 3-O-[xylosyl-(1 → 2)-(6''-succinylglucoside)] (3), pelargonidin 3-O-[xylosyl-(1 → 2)-(6''-E-p-coumaroylglucoside)] (4), pelargonidin 3-O-[xylosyl-(1 → 2)-(6''-Z-p-coumaroylglucoside)] (5), pelargonidin 3-O-[xylosyl-(1 → 2)-(6''-E-caffeoylglucoside)] (6) and cyanidin 3-O-[xylosyl-(1 → 2)-(6''-succinylglucoside)] (9) were reported in nature for the first time.
- Iwashina, Tsukasa,Mizuno, Takayuki,Rahayu, Sri,Sugahara, Kohtaro,Tsutsumi, Chie,Widyatmoko, Didik
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- Design, synthesis, and evaluation of different scaffold derivatives against NS2B-NS3 protease of dengue virus
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The number of deaths or critical health issues is a threat in the infection caused by Dengue virus, which complicates the situation, as only symptomatic treatment is the current solution. In this regard we have targeted the dengue protease NS2B-NS3 that is responsible for the replication. The series was designed with the help of molecular modeling approach using docking protocols. The series comprised of different scaffolds viz. cinnamic acid analogs (CA1–CA11), chalcone (C1–C10) and their molecular hybrids (Lik1–Lik10), analogs of benzimidazole (BZ1-BZ5), mercaptobenzimidazole (BS1-BS4), and phenylsulfanylmethylbenzimidazole (PS1-PS4). Virtual screening of various natural phytoconstituents was employed to determine the interactions of designed analogs with the residues of catalytic triad in the active site of NS2B-NS3. We have further synthesized the selected leads. The synthesized analogs were evaluated for the cytotoxicity and NS2B-NS3 protease inhibition activity and compared with known anti-dengue natural phytoconstituent quercetin as the standard. CA2, BZ1, and BS2 were found to be more potent and efficacious than the standard quercetin as evident from the protease inhibition assay.
- Ganji, Lata R.,Gandhi, Lekha,Musturi, Venkataramana,Kanyalkar, Meena A.
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p. 285 - 301
(2020/11/19)
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- Dual Nickel/Ruthenium Strategy for Photoinduced Decarboxylative Cross-Coupling of α,β-Unsaturated Carboxylic Acids with Cycloketone Oxime Esters
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Herein, a dual nickel/ruthenium strategy is developed for photoinduced decarboxylative cross-coupling between α,β-unsaturated carboxylic acids and cycloketone oxime esters. The reaction mechanism is distinct from previous photoinduced decarboxylation of α,β-unsaturated carboxylic acids. This reaction might proceed through a nickelacyclopropane intermediate. The C(sp2)-C(sp3) bond constructed by the aforementioned reaction provides an efficient approach to obtaining various cyanoalkyl alkenes, which are synthetically valuable organic skeletons in organic and medicinal chemistry, under mild reaction conditions. The protocol tolerates many critical functional groups and provides a route for the modification of complex organic molecules.
- Gao, Ang,Jiang, Run-Chuang,Liu, Chuang-Chuang,Liu, Qi-Le,Lu, Xiao-Yu,Xia, Ze-Jie
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supporting information
p. 8829 - 8842
(2021/06/30)
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- Reusable, magnetic Raney nickel based palladium catalysts for the Heck coupling in aqueous media
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Hybrid materials based on Pd- and Cu-doped Raney nickel appeared to be highly efficient catalysts for the Heck reaction in aqueous media in the absence of organic cosolvents. The catalysts can be easily removed by an external magnet and reused without losing catalytic activity.
- Bumagin, N. A.
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p. 2034 - 2040
(2021/11/05)
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- Ballodiolic acid a and b: Two new ros, (? oh), (onoo? ) scavenging and potent antimicrobial constituents isolated from ballota pseudodictamnus (l.) benth.
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Bioassays guided phytochemical investigations on the ethyl acetate-soluble fraction of the root material of Ballota pseudodictamnus (L.) Benth. led to the isolation of two new compounds, ballodiolic acid A (1) and ballodiolic acid B (2), along with three known compounds ballodiolic acid (3), ballotenic acid (4), and β-amyrin (5), which were also isolated for the first time from this species by using multiple chromatographic techniques. The structures of the compounds (1–5) were determined by modern spectroscopic analysis including 1D and 2D NMR techniques and chemical studies. In three separate experiments, the isolated compounds (1–5) demonstrated potent antioxidant scavenging activity, with IC50 values ranging from 07.22–34.10 μM in the hydroxyl radical (? OH) inhibitory activity test, 58.10–148.55 μM in the total ROS (reactive oxygen species) inhibitory activity test, and 6.23–69.01 μM in the peroxynitrite (ONOO? ) scavenging activity test. With IC50 values of (07.22 ± 0.03, 58.10 ± 0.07, 6.23 ± 0.04 μM) for? OH, total ROS, and scavenge ONOO?, respectively, ballodiolic acid B (2) showed the highest scavenging ability. Antibacterial and antifungal behaviors were also exposed to the pure compounds 1–5. In contrast to compounds 4 and 5, compounds 1–3 were active against all bacterial strains studied, with a good zone of inhibition proving these as a potent antibacterial agent. Similarly, compared to compounds 3–5, compounds 1 and 2 with a 47 percent and 45 percent respective inhibition zone were found to be more active against tested fungal strains.
- Ahmad, Ijaz,Ahmad, Nisar,Alobaid, Abdulrahman,Amin, Syed Badar,Bari, Ahmed,Fozia,Mahmood, Hafiz Majid,Shaheen, Asmat,Sohaib, Muhammad,Ullah, Riaz
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- Amino Group Functionalized Hf-Based Metal-Organic Framework for Knoevenagel-Doebner Condensation
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A Hf(IV) metal-organic framework (MOF) with di-amino functionalized linker was obtained as a crystalline solid with UiO-67 topology under solvothermal reaction conditions. The guest free form of Hf(IV) MOF (1′) was efficiently employed as a heterogeneous catalyst to synthesize cinnamic acid derivatives via Knoevenagel-Doebner reaction for the first time. The catalyst (1′) was efficiently active to directly achieve cinnamic acid from benzaldehyde and malonic acid. The solid retained its activity up to 6th cycle with no decay in its activity. The noticeable advantages of the catalyst are its milder reaction conditions, high yield, high stability, recyclable nature towards catalysis and wide substrate scope as well as shape-selective behaviour. The possible mechanism of the reaction was also studied thoroughly with suitable control experiments.
- Das, Aniruddha,Anbu, Nagaraj,Gogoi, Chiranjib,Dhakshinamoorthy, Amarajothi,Biswas, Shyam
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p. 3396 - 3403
(2021/08/20)
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- Understanding the role played by protic ionic liquids (PILs) and the substituent effect for enhancing the generation of: Z-cinnamic acid derivatives
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Photoisomerization of a series of substituted E-cinnamic acids in MeCN in their acid forms and as their corresponding protic ionic liquids (PILs) with light of 300 nm is studied. The nature, strength, number, and position effects of substituents on the photochemical behavior of E-cinnamic derivatives are investigated. The photosensitization of the reaction in the presence of Michler's ketone is also studied at 366 nm and it demonstrates that the triplet-excited state is involved in the reaction. As the presence of n-butylamine needed to form the PILs significantly increases the photoproduct yields in all cases, the role of the PILs is also discussed. Thus, understanding of these fundamental aspects has allowed us to establish an excellent and practical synthetic protocol for successfully synthesizing Z-cinnamic acids. This journal is
- Rodríguez, Roció B.,Rodríguez, Roció B.,Zapata, Ramiro L.,Salum, Mariá L.,Salum, Mariá L.,Erra-Balsells, Rosa,Erra-Balsells, Rosa
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p. 819 - 830
(2020/07/03)
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- Identification of novel functionalized carbohydrazonamides designed as chagas disease drug candidates
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Background: Although several research efforts have been made worldwide to discover novel drug candidates for the treatment of Chagas disease, the nitroimidazole drug benznidazol remains the only therapeutic alternative in the control of this disease. However, this drug presents reduced efficacy in the chronic form of the disease and limited safety after long periods of admini-stration, making it necessary to search for new, more potent and safe prototypes. Objective: We described herein the synthesis and the trypanocidalaction of new functionalized carbohydrazonamides (2-10) against trypomastigote forms of Trypanosoma cruzi. Methods: These compounds were designed through the application of molecular hybridization concept between two potent anti-T. cruzi prototypes, the nitroimidazole derivative megazol (1) and the cinnamyl N-acylhydrazone derivative (14) which have been shown to be twice as potent in vitro as benznidazole. Results: The most active compounds were the (Z)-N'-((E)-3-(4-nitrophenyl)-acryloyl)-1-methyl-5-nitro-1H-imidazol-2-carbohydrazonamide (6) (IC50 =9.50 μM) and the (Z)-N'-((E)-3-(4-hydroxyphe-nyl)-acryloyl)-1-methyl-5-nitro-1H-imidazol-2-carbohydrazonamide (8) (IC50 =12.85 μM), which were almost equipotent to benznidazole (IC50 =10.26 μM) used as standard drug. The removal of the amine group attached to the imine subunit in the corresponding N-acylhydrazone derivatives (11-13) resulted in less potent or inactive compounds. The para-hydroxyphenyl derivative (8) presented also a good selectivity index (SI = 32.94) when tested against mammalian cells from Swiss mice. Conclusion: The promising trypanocidal profile of new carbohydrazonamide derivatives (6) and (8) was characterized. These compounds have proved to be a good starting point for the design of more effective trypanocidal drug candidates.
- Do Nascimento, Mayara S. S.,Camara, Vitória R. F.,da Costa, Juliana S.,Barbosa, Juliana M. C.,Lins, Alessandra S. M.,Salom?o, Kelly,de Castro, Solange L.,Carvalho, Samir A.,da Silva, Edson F.,Fraga, Carlos A. M.
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p. 774 - 783
(2020/08/19)
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- Exploring bulky natural and natural-like periphery in the design of p-(benzyloxy)phenylpropionic acid agonists of free fatty acid receptor 1 (GPR40)
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Six derivatives of 3-phenylpropionic acid bearing various natural and natural-like, spatially defined peripheral motifs have been synthesized and evaluated in vitro for free fatty acid receptor 1 (FFA1) activation. Two frontrunner compounds (bearing a bornyl and cytosine groups) were evaluated in an oral glucose tolerance test in mice where both demonstrated the ability to sustain blood glucose levels following a glucose challenge. The bornyl compound displayed a somewhat superior, dose-dependent efficacy and, therefore, can be regarded as a lead compounds for further development as a therapeutic agent for type 2 diabetes mellitus. Its high affinity to FFA1 was rationalized by docking experiments.
- Gureev, Maxim,Krasavin, Mikhail,Kuranov, Sergey O.,Luzina, Olga A.,Onopchenko, Oleksandra,Pishel, Iryna,Salakhutdinov, Nariman F.,Zozulya, Sergey
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- Synthesis and evaluation of new 1,2,4-oxadiazole based trans- acrylic acid derivatives as potential PPAR-alpha/gamma dual agonist
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Diabetes is a ubiquitously a metabolic disorder and life-threatening disease. Peroxisome proliferator-activated receptors (PPARs) belong to the class of nuclear receptors which acts as transcription factors to regulate lipid and glucose metabolism. PPAR alpha/gamma dual agonists tend to corroborate the functions of both thiazolidinediones and fibrates and they hold substantial promise for ameliorating the type 2 diabetic treatments and providing potential therapeutic diabetic interventions. New 1,2,4-oxadiazole based trans- acrylic acid derivatives compounds possessing aryl/methylene linker in between pharmacophore head and lipophilic tail for dual PPAR-alpha/gamma agonists are studied. AutoDock Vina used for potential PPAR alpha/gamma dual agonists and 6 compounds 9a, 9g, 9 m, 9n, 9o, and 9r were identified comparable to PPAR gamma agonist Pioglitazone on the basis of their affinity scores and further their in-silico toxicity and in-silico ADME properties. The selected compounds showed better-calculated lipophilicity (iLogP) was found to be 0.92 to 3.19. Compound 9n and 9a were found to be most potent on both PPAR alpha and gamma receptors with EC50 of 0.07 ± 0.0006 μM, 0.06 ± 0.0005 μM and 0.781 ± 0.008 μM, 3.29 μM ± 0.03 respectively as better to pioglitazone having EC50 of 32.38 ± 0.2 and 38.03 ± 0.13 for both receptors. The in-vivo evaluation found to reduce the plasma glucose level and total cholesterol level significantly in diabetic rats compared to pioglitazone at 5 mg/kg/day dose for 7 days of treatment. Thus, trans- acrylic acid derivatives can be further developed as oral therapeutic agents for diabetic interventions as PPAR alpha/gamma dual agonists.
- Bhat, Sana,Bhat, Zahid Rafiq,Gupta, Jeena,Kaur, Jaskiran,Kaur, Paranjeet,Khatik, Gopal L.,Khurana, Navneet,Kumar, Rajan,Kumar, Rakesh,Tikoo, Kulbhushan
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- Bioassay of ferulic acid derivatives as influenza neuraminidase inhibitors
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Four series of ferulic acid derivatives were designed, synthesized, and evaluated for their neuraminidase (NA) inhibitory activities against influenza virus H1N1 in vitro. The pharmacological results showed that the majority of the target compounds exhibited moderate influenza NA inhibitory activity, which was also better than that of ferulic acid. The two most potent compounds were 1m and 4a with IC50 values of 12.77 ± 0.47 and 12.96 ± 1.34 μg/ml, respectively. On the basis of the biological results, a preliminary structure–activity relationship (SAR) was derived and discussed. Besides, molecular docking was performed to study the possible interactions of compounds 1p, 2d, 3b, and 4a with the active site of NA. It was found that the 4-OH-3-OMe group and the amide group (CON) of ferulic acid amide derivatives were two key pharmacophores for NA inhibitory activity. It is meaningful to further modify the natural product ferulic acid to improve its influenza NA inhibitory activity.
- Cui, Man-Ying,Xiao, Meng-Wu,Xu, Lv-Jie,Chen, Yun,Liu, Ai-Lin,Ye, Jiao,Hu, Ai-Xi
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- Targeting inflammation with conjugated cinnamic amides, ethers and esters
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Background: Cinnamic acid is a key intermediate in shikimate and phenylpropanoid pathways. It is found both in free form, and especially in the form of esters in various essential oils, resins and balsams which are very important intermediates in the biosynthetic pathway of several natural products. The cinnamic derivatives play a vital role in the formation of commercially important intermediate molecules which are necessary for the production of different bioactive compounds and drugs. Different substitutions on basic moiety lead to various biological activities. Furthermore, combination of appropriate pharmacophore groups with cinnamic acid derivatives were developed to give hybrids in order to find out promising drug candidates as inhibitors of multiple biological targets associated with inflammation. We found interesting to continue our efforts to design and synthesise three series of novel cinnamic acid-based hybrids: a) nitrooxy esters of cinnamic acid, b) ethers and c) amides of cinnamic acids with arginine, as pleiotropic candidates against multiple targets of inflammation Methods: The synthesis of cinnamic was established by a Knoevenagel-Doebner condensation of the suitable aldehyde either with malonic acid in the presence of pyridine and piperidine, or with phenylacetic acid in the precence of triethylamine in acetic anhydride. The synthesis of the corresponding esters was conducted in two steps. The ethers were synthesized in low yields, with 1,2 – dibromoethane in dry acetone, in the presence of K2CO3, to give oily products. The corresponding cinnamic amides were synthesised in a single step. The synthesised hybrids were tested as lipoxygenase (LOX) and cyclooxygenase (COX) inhibitors in vitro. In silico docking was applied to all the novel derivatives. Several molecular properties of the hybrids were calculated in order to evaluate their drug likeness. Results: A number of esters, ethers and amides of selected cinnamic acids, either phenyl substituted or not, has been synthesised and subjected to modelling studies. The compounds were studied in vitro/in vivo for their inhibitory activities on cox and lox, and as antioxidants. Log P values of all the title compounds except of 3a (5.38) were found to be less than 5 and are in agreement to Lipinski’s rule of five, suggesting satisfactory permeability across cell membrane. The molecular modelling study seems to be in accordance with the experimental results for LOX and COX-2. The result of antioxidant activity for amide 3b supports the anti-lox activity. Compound 5d presents the higher in vivo anti-inflammatory. Conclusion: According to the experimental findings compounds 3b and 5d can be used as lead compounds for the design of new molecules to target inflammation.
- Fotopoulos, Ioannis,Litina, Dimitra Hadjipavlou,Pontiki, Eleni
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- Design and synthesis of novel tranilast analogs: Docking, antiproliferative evaluation and in-silico screening of TGFβR1 inhibitors
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The discovery of the antiproliferative potential of tranilast prompted additional studies directed at understanding the mechanisms of tranilast action. Its inhibitory effect on cell proliferation depends principally on the capacity of tranilast to interfere with transforming growth factor beta (TGFβR1) signaling. This work summarizes design, synthesis and biological evaluation of sixteen novel tranilast analogs on different tumors such as PC-3, HepG-2 and MCF-7 cell lines. The in vitro cytotoxicity was evaluated using MTT assay showed that, twelve compounds out of sixteen showed higher cytotoxic activities (IC50’s 1.1–6.29 μM), than that of the reference standard, 5-FU (IC50 7.53 μM). The promising cytotoxic hits (4b, 7a, b and 14c-e), proved to be selective to cancer cells when their cytotoxicity's are examined on human normal cell line (WI-38). Then they are investigated for their possible mode of action as TGFβR1 inhibitors; remarkable inhibition of TGFβR1 by these hits was observed at the range of IC50 0.087–3.276 μM. The cell cycle analysis of the most potent TGFβR1 inhibitor, 4b revealed cell cycle arrest at G2/M phase on prostate cancer cells. Additionally, it is clearly indicated apoptosis induction at Pre-G1 phase, this is substantiated by significant increase in the expression on the tumor suppressor gene, p53 and up regulation the level of apoptosis mediator, caspase-3. In addition, in silico study was performed for validating the physicochemical and ADME properties which revealed that, all compounds are orally bioavailable with no side effects complying with Lipinski rule. The proposed mode of action can be further explored on the light of molecular modeling simulation of the most potent compounds, 4b and 14e which were docked into the active sites of TGFβR1 to predict their affinities toward the receptor.
- Ismail, Magda M.F.,El-Zahabi, Heba S.A.,Ibrahim, Rabab S.,Mehany, Ahmed B.M.
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- Expeditious and sustainable two-step synthesis of sinapoyl-l-malate and analogues: Towards non-endocrine disruptive bio-based and water-soluble bioactive compounds
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Faced with the increasing demand from both the cosmetic industries and consumers for bio-based, safe and natural skin products, sinapoyl-l-malate, widely described for its UV protection in plants, appears to be an excellent alternative to substitute chemical filters in sunscreens. Unfortunately, the only synthetic routes described in the literature were not only tedious but also exhibit a strong negative environmental impact, thus seriously limiting the industrialization and commercialization of sinapoyl-l-malate. Herein, a shorter and greener synthetic pathway involving Meldrum's acid opening with unprotected naturally occurring hydroxy acids and its subsequent Knoevenagel-Doebner condensation with biomass-derived p-hydroxybenzaldehydes was designed and developed. This two-step procedure, whom sustainability has been assessed using green metrics (atom economy (AE), process atom economy (PAE), E-factor and LCA), is a great alternative to the already reported procedures and allows the access to sinapoyl-l-malate and several analogs in average to good yield. The study of the anti-UV properties, stability against UV radiation, radical scavenging and antimicrobial activities of the targets revealed attractive properties as photostable UV filters, antioxidants and preservatives. Moreover, the water solubility brought by the free carboxylic acids facilitates the incorporation of these molecules in cosmetic formulations. Finally, their innocuousness toward endocrine disruption was demonstrated.
- Peyrot, Cédric,Mention, Matthieu M.,Fournier, Robin,Brunissen, Fanny,Couvreur, Julien,Balaguer, Patrick,Allais, Florent
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supporting information
p. 6510 - 6518
(2020/11/09)
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- The fate of acylated anthocyanins in mildly heated neutral solution
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In neutral solution, anthocyanins acylated by hydroxycinnamic acids typically exhibit attractive blue colors and a higher resistance to color loss compared to their nonacylated homologs. However, they remain vulnerable to a poorly understood combination of oxidative and hydrolytic reactions that strongly contribute to color loss and limits their industrial applications. In this work, the thermal degradation of isolated red cabbage anthocyanins (0, 1 or 2 acyl groups) at pH 7 was investigated by UPLC-DAD-MS (low- and high-resolution). Non-oxidative alterations, including deacylation and intramolecular acyl transfer, were observed and found very dependent on the number and position of the acyl group(s) as well as on the presence of iron ions. At intermediate and advanced thermal degradation, several oxidative mechanisms were evidenced that lead to protocatechuic acid, phloroglucinaldehyde 2-O-glucoside, acylglycosides and derivatives of 2,4,6-trihydroxyphenylacetic acid and 3,5,7-trihydroxycoumarin. Based on the product distribution observed and on the impact of added Fe2+ ions and H2O2, possible degradation mechanisms are discussed. They likely start with a one- or two-electron transfer from the anionic base (a major colored form in neutral solution) to O2. The hydrogen peroxide produced could then further react as an electrophile with the anionic base and/or the hemiketal (major colorless hydrated form). This contribution to understanding the degradation mechanisms of anthocyanins around neutrality can open up new stabilization strategies to extend the range of their food applications to neutral media.
- Collins, Thomas M.,Dangles, Olivier,Fenger, Julie-Anne,Robbins, Rebecca J.
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- Knoevenagel-Doebner condensation promoted by chitosan as a reusable solid base catalyst
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The development of green and sustainable processes using naturally occurring biopolymers is becoming one of the suitable remedies to replace the conventional catalytic systems that generate large amount of byproducts with high risk factors. In this context, although Knoevenagel-Doebner condensation reaction has been reported with many organocatalysts including proline, no attempts were made to develop heterogeneous catalysts with environmental concerns. Considering these factors in mind, the title reaction is studied with chitosan as a heterogeneous solid base catalyst for the synthesis of α,β-unsaturated carboxylic acids through the condensation followed by decarboxylation reactions. Chitosan offers many advantages including high stability as evidenced by leaching, reusability tests, wide substrate scope and providing higher yields of the desired products with high purity. Powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscope (SEM) and elemental analysis revealed that there are no major changes in the structural integrity and morphology of chitosan before and after catalysis under the optimized reaction conditions.
- Anbu, Nagaraj,Hariharan, Surendran,Dhakshinamoorthy, Amarajothi
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- Copper and L-(?)-quebrachitol catalyzed hydroxylation and amination of aryl halides under air
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L-(?)-Quebrachitol, a natural product obtained from waste water of the rubber industry, was utilized as an efficient ligand for the copper-catalyzed hydroxylation and amination of aryl halides to selectively give phenols and aryl amines in water or 95percent ethanol. In addition, the hydroxylation of 2-chloro-4-hydroxybenzoic acid was validated on a 100-g scale under air.
- Bao, Xuefei,Chen, Guoliang,Dong, Jinhua,Du, Fangyu,Li, Hui,Liang, Xinjie,Wu, Ying,Zhang, Yongsheng
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supporting information
(2020/08/03)
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- Salen-porphyrin-based conjugated microporous polymer supported Pd nanoparticles: Highly efficient heterogeneous catalysts for aqueous C-C coupling reactions
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The salen-porphyrin based conjugated microporous polymer (SP-CMP) was first constructed by polycondensation reaction of a salen-dialdehyde derivative and pyrrole. Due to the outstanding chemical and thermal stability, abundant micropores with a reasonable pore size, and ordered salen-porphyrin arrays in the A4B4-type polymer framework, the functional CMP was further applied as a Pd nanoparticle support by the coordinate interactions between the polydentate chelating sites with Pd(OAc)2 and subsequent reduction with NaBH4. The as-synthesized composite material (Pd@SP-CMP) was fully characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and solid-state 13C nuclear magnetic resonance (NMR). The porous property of Pd@SP-CMP was also characterized by N2 adsorption/desorption isotherms and the obtained material exhibited a Brunauer-Emmett-Teller (BET) surface area of 266 m2 g-1, together with a pore volume of 0.192 cm3 g-1. The microscopic morphology of Pd@SP-CMP was further evaluated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The Pd@SP-CMP material with highly dispersed Pd nanoparticles exhibited excellent catalytic activity towards Suzuki-Miyaura and Heck-Mizoroki coupling reactions in water or in the dioxane/water mixture. In addition, Pd@SP-CMP also displayed outstanding stability and recyclability, and it can be reused without loss of activity in ten successive reactions. More importantly, the salen-porphyrin based CMPs could be the promising candidates for developing high-performance heterogeneous catalysts.
- Ju, Pengyao,Wu, Shujie,Su, Qing,Li, Xiaodong,Liu, Ziqian,Li, Guanghua,Wu, Qiaolin
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supporting information
p. 2660 - 2666
(2019/02/12)
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- Synthesis and biological evaluation of 2,2-dimethylbenzopyran derivatives as potent neuroprotection agents
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The development of novel neuroprotection agents is of great significance for the treatment of ischemic stroke. In this study, a series of compounds comprising 2,2-dimethylbenzopyran groups and cinnamic acid groups have been synthesized. Preferential combination principles and bioisostere that improved the neuroprotective effect of the compounds were identified for this series via biological activity assay in vitro. Meanwhile, a functional reversal group of the acrylamide amide resulted in the most active compounds. Among them, BN-07 significantly improved the morphology of neurons and obviously increased cell survival rate of primary neurons induced by oxygen glucose deprivation (OGD), superior to clinically used anti-ischemic stroke drug edaravone (Eda). Overall, our findings may provide an alternative strategy for the design of novel anti-ischemic stroke agents with more potency than Eda.
- Du, Fangyu,Zhou, Qifan,Fu, Xiaoxiao,Shi, Yajie,Chen, Yuanguang,Fang, Wuhong,Yang, Jingyu,Chen, Guoliang
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p. 2498 - 2508
(2019/02/01)
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- Synthesis and Hypoglycemic Activity of Aryl(Hetaryl)Propenoic Cyanopyrrolidine Amides
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Abstract: A series of amides based on (2S)-cyanopyrrolidine and α, β-unsaturated aryl- and hetarylcarboxylic acids have been synthesized. The dependence of the hypoglycemic activity of compounds on the structure of the aromatic fragment has been studied in the oral glucose tolerance test in mice. Amides based on (E)-3-phenylprop-2-enoic and (E)-3-(4-methoxyphenyl)prop-2-enoic acids and (2S)-cyanopyrrolidine have been shown to significantly reduce blood glucose levels in mice. The observed hypoglycemic effect at a dose of 10 mg/kg is comparable to the effect of hypoglycemic drug vildagliptin.
- Kuranov,Blokhin,Borisov,Khvostov,Luzina,Salakhutdinov
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p. 374 - 380
(2019/10/28)
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- Application of quebrachitol in hydrolysis reaction of copper-catalyzed aryl halide
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The invention belongs to the technical field of drug synthesis, and provides application of quebrachitol in a hydrolysis reaction of a copper-catalyzed aryl halide. According to the hydrolysis reaction, copper serves as a catalyst, quebrachitol serves as a ligand, and the hydrolysis reaction is carried out on the aryl halide. The invention further provides a catalytic system of the hydrolysis reaction of the aryl halide. The reaction system comprises the copper catalyst, the quebrachitol, alkali and water, and the system is environmentally friendly and is suitable for industrial application.
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Paragraph 0063-0065
(2019/07/16)
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- Structure-aided drug development of potential neuraminidase inhibitors against pandemic H1N1 exploring alternate binding mechanism
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Abstract: The rate of mutability of pathogenic H1N1 influenza virus is a threat. The emergence of drug resistance to the current competitive inhibitors of neuraminidase, such as oseltamivir and zanamivir, attributes to a need for an alternative approach. The design and synthesis of new analogues with alternate approach are particularly important to identify the potential neuraminidase inhibitors which may not only have better anti-influenza activity but also can withstand challenge of resistance. Five series of scaffolds, namely aurones (1a–1e), pyrimidine analogues (2a–2b), cinnamic acid analogues (3a–3k), chalcones (4a–4h) and cinnamic acid linkages (5a–5c), were designed based on virtual screening against pandemic H1N1 virus. Molecular modelling studies revealed that the designed analogues occupied 430-loop cavity of neuraminidase. Docking of sialic acid in the active site preoccupied with the docked analogues, i.e. in 430-loop cavity, resulted in displacement of sialic acid from its native pose in the catalytic cavity. The favourable analogues were synthesized and evaluated for the cytotoxicity and cytopathic effect inhibition by pandemic H1N1 virus. All the designed analogues resulting in displacement of sialic acid suggested alternate binding mechanism. Overall results indicated that aurones can be measured best among all as potential neuraminidase inhibitor against pandemic H1N1 virus. Graphical abstract: [Figure not available: see fulltext.].
- Malbari, Khushboo D.,Chintakrindi, Anand S.,Ganji, Lata R.,Gohil, Devanshi J.,Kothari, Sweta T.,Joshi, Mamata V.,Kanyalkar, Meena A.
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p. 927 - 951
(2019/02/07)
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- Substituted styrene preparation method
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The invention belongs to the technical field of synthesis of chemical and medical intermediates, and relates to a substituted styrene preparation method, in particular to a method for preparing substituted styrene by using an ionic solution. In the method, the ionic solution is used as a solvent, and the reaction catalyzing efficiency is high. The ionic solution can be repeatedly used, industrialproduction cost is saved, and environment problems caused by a traditional solvent are solved favorably.
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Paragraph 0023-0025; 0041-0045
(2019/02/26)
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- Method for preparing styrene derivative from ionic liquid
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The invention belongs to the technical field of chemical engineering and pharmaceutical intermediate synthesis and relates to a method for preparing a styrene derivative from ionic liquid. The methodhas advantages that by adoption of the ionic liquid as a solvent, high reaction catalyzing efficiency is achieved; due to reusability of the ionic liquid, industrial production cost is saved, and theenvironment problem caused by traditional solvents can be solved helpfully.
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Paragraph 0023-0025; 0041-0046
(2019/04/06)
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- A method for the preparation of substituted styrene ion solution method
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The invention belongs to chemical and pharmaceutical intermediate synthesis technology field, relates to a process for preparing a substituted styrene ion solution method. The method takes the ionic liquid as solvent, reaction of high catalytic efficiency. The ionic liquid can be used repeatedly, save the industrialized production cost, and to facilitate the solution of the environmental problem of traditional solvent.
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Paragraph 0023; 0024; 0025; 0041; 0042; 0043; 0044-0046
(2019/04/02)
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- Synthesis and biological evaluation of 4-arylcoumarins as potential anti-Alzheimer's disease agents
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Alzheimer's disease (AD) is a progressive neurological degenerative disease that has complex pathogenesis. A variety of studies in humans indicate that several enzymes inhibitors can be useful in the treatment of AD, including acetylcholinesterase (AchE), butyrylcholinesterase (BuChE) and monoamine oxidase (MAO). Various substituted 4-arylcoumarin derivatives were synthesised, and their activity in vitro were investigated, including AChE/BuChE inhibitory activity, MAO inhibitory activity, and antioxidant activity. Most of the compounds were found to exhibit high inhibitory activity, and individual compounds have extremely excellent activities. Therefore 4-arylcoumarins provides an idea for drugs design for the development of therapeutic or preventive agents for AD.
- Miao, Yuhang,Sun, Jie,Wang, Xiaojing,Yang, Jie,Yun, Yinling
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- Comprehensive kinetic and substrate specificity analysis of an arylsulfatase from Helix pomatia using mass spectrometry
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Sulfatases hydrolyze sulfated metabolites to their corresponding alcohols and are present in all domains of life. These enzymes have found major application in metabolic investigation of drugs, doping control analysis and recently in metabolomics. Interest in sulfatases has increased due to a link between metabolic processes involving sulfated metabolites and pathophysiological conditions in humans. Herein, we present the first comprehensive substrate specificity and kinetic analysis of the most commonly used arylsulfatase extracted from the snail Helix pomatia. In the past, this enzyme has been used in the form of a crude mixture of enzymes, however, recently we have purified this sulfatase for a new application in metabolomics-driven discovery of sulfated metabolites. To evaluate the substrate specificity of this promiscuous sulfatase, we have synthesized a series of new sulfated metabolites of diverse structure and employed a mass spectrometric assay for kinetic substrate hydrolysis evaluation. Our analysis of the purified enzyme revealed that the sulfatase has a strong preference for metabolites with a bi- or tricyclic aromatic scaffold and to a lesser extent for monocyclic aromatic phenols. This metabolite library and mass spectrometric method can be applied for the characterization of other sulfatases from humans and gut microbiota to investigate their involvement in disease development.
- Correia, Mário S.P.,Ballet, Caroline,Meistermann, Hannes,Conway, Louis P.,Globisch, Daniel
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p. 955 - 962
(2019/02/09)
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- Four New Flavonoids Isolated from the Aerial Parts of Cadaba rotundifolia Forssk. (Qadab)
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Cadaba rotundifolia (Forssk.) (family: Capparaceae; common name: Qadab) is one of four species that grow in the Red Sea costal region in the Kingdom of Saudi Arabia. The roots and leaves of C. rotundifolia is traditionally used to treat tumors and abscesses in Sudan. A previous phytochemical study of the roots yielded a quaternary alkaloid, but no report on chemical constituents of the aerial parts of the C. rotundifolia growing in Saudi Arabia has been issued so far. Oxidative stress and advanced glycation end products (AGEs) are thought as causal factors in many degenerative diseases, such as Alzheimer's disease, diabetes, atherosclerosis and aging. In this study, a total of twenty compounds, including four previously undescribed acylated kaempferol glucosides, were isolated from the aerial parts of C. rotundifolia collected in Saudi Arabia. These new compounds were identified as kaempferol 3-O-[2-O-(trans-feruloyl)-3-O-β-d-glucopyranosyl]-β-d-glucopyranoside (1), kaempferol 3-O-β-neohesperidoside-7-O-[2-O-(cis-p-coumaroyl)-3-O-β-d-glucopyranosyl]-β-d-glucopyranoside (2), kaempferol 3-O-[2,6-di-O-α-l-rhamnopyranosyl]-β-d-glucopyranoside-7-O-[6-O-(trans-feruloyl)]-β-d-glucopyranoside (3) and kaempferol 3-O-[2,6-di-O-α-l-rhamnopyranosyl]-β-d-glucopyranoside-7-O-[6-O-(trans-p-coumaroyl)]-β-d-glucopyranoside (4). Their structures were established based on UV-visible, 1D, 2D NMR, and HR-ESI-MS analyses. Of the assayed compounds, 17 and 18 showed potent radical scavenging activity with IC50 values of 14.5 and 11.7 μM, respectively, and inhibitory activity toward AGEs together with compound 7 with IC50 values 96.5, 34.9 and 85.5 μM, respectively.
- Al-Hamoud, Gadah Abdulaziz,Orfali, Raha Saud,Sugimoto, Sachiko,Yamano, Yoshi,Alothyqi, Nafee,Alzahrani, Ali Mohammed,Matsunami, Katsuyoshi
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- Revelation of the Balanol Biosynthetic Pathway in Tolypocladium ophioglossoides
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A cryptic gene cluster, bln, was activated by genome mining in Tolypocladium ophioglossoides. This activation led to the production of balanol and eight other metabolites. Gene disruption and metabolite profile analysis showed that the biosynthesis of balanol involved the convergence of independent PKS and NRPS pathways, and a biosynthetic pathway for balanol was proposed.
- He, Xian,Zhang, Min,Guo, Yuan-Yang,Mao, Xu-Ming,Chen, Xin-Ai,Li, Yong-Quan
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supporting information
p. 6323 - 6326
(2018/10/15)
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- Lithium perchlorate catalyzed electrophilic activation: A convenient one-pot synthesis of trans-cinnamic acids
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Background: Currently perchlorate catalysts gain much attention in organic synthesis due to ease of operation, wide applicability, high yield, and economy. This is evident through increasing number of citation related to their application in industry as well as other allied fields. The aim of this paper is to describe a methodology using lithium perchlorate to catalyze the Knoevenagel condensation reaction for the synthesis of biologically active trans-cinnamic acid in good to excellent yield. Methods: We discuss herein an economic, user-friendly one-pot synthesis of trans-cinnamic acids by refluxing a mixture of a malonic acid with aryl aldehyde in pyridine. The product was easily isolated via filtration and thereafter washed and characterized by spectroscopic methods. Results: This method is robust, stereoselective and high yielding. It can be utilized to synthesize a wide array of trans-cinnamic acids in good to excellent yield using 20% of lithium perchlorate catalyst. It is also useful in the synthesis of aliphatic α,β-unsaturated carboxylic acid. Conclusion: The role of lithium perchlorate as a mild catalyst in the synthesis of trans-cinnamic acid was explored. The reactions afforded a good yield of various products with simpler isolation.
- Kaur, Paranjeet,Khatik, Gopal L.
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p. 688 - 692
(2018/07/13)
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- Novel piperazine amides of cinnamic acid derivatives as tyrosinase inhibitors
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Background: A series of novel cinnamic acid piperazine amide derivatives has been designed and synthesized, and their biological activities were also evaluated as potential tyrosinase inhibitors. Methods: Compounds 9, 11 and 17 showed the most potent biological activity (IC50 = 66.5, 61.1 and 66 μM, respectively). In silico docking simulation was performed to position compound 11 into the Agaricus bisporus mushroom tyrosinase’s active site to determine the putative binding interactions. Results and Conclusion: The results indicated that compound 11 could serve as a promising lead compound for further development of potent tyrosinase inhibitors.
- Gür, Zehra Tu??e,?enol, Fatma Sezer,Shekfeh, Suhaib,Orhan, ?lkay Erdo?an,Bano?lu, Erden,?ali?kan, Burcu
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- 2,2-dimethylbenzopyran derivative and preparation method and use thereof
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The invention belongs to the technical field of medicines, and discloses a 2,2-dimethylbenzopyran derivative and a preparation method and use of the 2,2-dimethylbenzopyran derivative. The derivative and pharmaceutically acceptable salt of the derivative have the structural formulae shown in the description, wherein Ar, Ar, X, Y and R1 are as described in the claims and the description. The preparation methods of the derivative and the pharmaceutically acceptable salt of the derivative comprise the following steps: the formula (I) is obtained by mainly taking acetaminophen as a raw material, and subjected to the reactions of Williamson ether formation, cyclization, hydrolysis, amide formation and the like; the formula II is obtained by mainly taking p-hydroxybenzaldehyde as a raw material, and subjected to the reactions of the Williamson ether formation, cyclization, Knoevenagel condensation, amide formation and the like. The derivative and the pharmaceutically acceptable salt ofthe derivative disclosed by the invention can be used for preparing neuroprotective agents and have better neuroprotective effects on ischemic stroke.
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Page/Page column 13
(2019/01/16)
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- Discovery of caffeic acid phenethyl ester derivatives as novel myeloid differentiation protein 2 inhibitors for treatment of acute lung injury
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Myeloid differentiation protein 2 (MD2) is an essential molecule which recognizes lipopolysaccharide (LPS), leading to initiation of inflammation through the activation of Toll-like receptor 4 (TLR4) signaling. Caffeic acid phenethyl ester (CAPE) from propolis of honeybee hives could interfere interactions between LPS and the TLR4/MD2 complex, and thereby has promising anti-inflammatory properties. In this study, we designed and synthesized 48 CAPE derivatives and evaluated their anti-inflammatory activities in mouse primary peritoneal macrophages (MPMs) activated by LPS. The most active compound, 10s, was found to bind with MD2 with high affinity, which prevented formation of the LPS/MD2/TLR4 complex. The binding mode of 10s revealed that the major interactions with MD2 were established via two key hydrogen bonds and hydrophobic interactions. Furthermore, 10s showed remarkable protective effects against LPS-caused ALI (acute lung injury) in vivo. Taken together, this work provides new lead structures and candidates as MD2 inhibitors for the development of anti-inflammatory drugs.
- Chen, Lingfeng,Jin, Yiyi,Chen, Hongjin,Sun, Chuchu,Fu, Weitao,Zheng, Lulu,Lu, Min,Chen, Pengqin,Chen, Gaozhi,Zhang, Yali,Liu, Zhiguo,Wang, Yi,Song, Zengqiang,Liang, Guang
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p. 361 - 375
(2017/12/07)
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- Design, synthesis and in combo antidiabetic bioevaluation of multitarget phenylpropanoic acids
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We have synthesized a small series of five 3-[4-arylmethoxy)phenyl]propanoic acids employing an easy and short synthetic pathway. The compounds were tested in vitro against a set of four protein targets identified as key elements in diabetes: G protein-coupled receptor 40 (GPR40), aldose reductase (AKR1B1), peroxisome proliferator-activated receptor gama (PPARγ) and solute carrier family 2 (facilitated glucose transporter), member 4 (GLUT-4). Compound 1 displayed an EC50 value of 0.075 μM against GPR40 and was an AKR1B1 inhibitor, showing IC50 = 7.4 μM. Compounds 2 and 3 act as slightly AKR1B1 inhibitors, potent GPR40 agonists and showed an increase of 2 to 4-times in the mRNA expression of PPARγ, as well as the GLUT-4 levels. Docking studies were conducted in order to explain the polypharmacological mode of action and the interaction binding mode of the most active molecules on these targets, showing several coincidences with co-crystal ligands. Compounds 1–3 were tested in vivo at an explorative 100 mg/kg dose, being 2 and 3 orally actives, reducing glucose levels in a non-insulin-dependent diabetes mice model. Compounds 2 and 3 displayed robust in vitro potency and in vivo efficacy, and could be considered as promising multitarget antidiabetic candidates. This is the first report of a single molecule with these four polypharmacological target action.
- Colín-Lozano, Blanca,Estrada-Soto, Samuel,Chávez-Silva, Fabiola,Gutiérrez-Hernández, Abraham,Cerón-Romero, Litzia,Giacoman-Martínez, Abraham,Almanza-Pérez, Julio Cesar,Hernández-Nú?ez, Emanuel,Wang, Zhilong,Xie, Xin,Cappiello, Mario,Balestri, Francesco,Mura, Umberto,Navarrete-Vazquez, Gabriel
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- Electrochemical Lignin Degradation in Ionic Liquids on Ternary Mixed Metal Electrodes
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Lignin is the second most abundant natural polymer and a promissing feedstock for the generation of renewable aromatic chemicals. We present an fundamental approach for the electrocatalytic cleavage of lignin dissolved in a recoverable, inexpensive ionic liquid using mixed metal oxide electrodes of different compositions. The distribution of depolymerization products generated by electrochemical oxidation were analyzed by means of mass spectrometry. The distribution and yield of the cracked species was found to depended strongly on the implemented metal catalyst and therefore offers the potential to tailor the amount and composition of the low molecular weight cleavage products. This approach could help to provide a more sustainable valorization of lignin for the potential production of high value aromatic compounds due to synergistic effects.
- Rauber, Daniel,Dier, Tobias K.F.,Volmer, Dietrich A.,Hempelmann, Rolf
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p. 189 - 208
(2017/12/18)
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- Pseudomonas fluorescens Strain R124 Encodes Three Different MIO Enzymes
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A number of class I lyase-like enzymes, including aromatic ammonia-lyases and aromatic 2,3-aminomutases, contain the electrophilic 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO) catalytic moiety. This study reveals that Pseudomonas fluorescens R124 strain isolated from a nutrient-limited cave encodes a histidine ammonia-lyase, a tyrosine/phenylalanine/histidine ammonia-lyase (XAL), and a phenylalanine 2,3-aminomutase (PAM), and demonstrates that an organism under nitrogen-limited conditions can develop novel nitrogen fixation and transformation pathways to enrich the possibility of nitrogen metabolism by gaining a PAM through horizontal gene transfer. The novel MIO enzymes are potential biocatalysts in the synthesis of enantiopure unnatural amino acids. The broad substrate acceptance and high thermal stability of PfXAL indicate that this enzyme is highly suitable for biocatalysis.
- Csuka, Pál,Juhász, Vivien,Kohári, Szabolcs,Filip, Alina,Varga, Andrea,Sátorhelyi, Péter,Bencze, László Csaba,Barton, Hazel,Paizs, Csaba,Poppe, László
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p. 411 - 418
(2018/02/27)
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- METHOD FOR THE SYNTHESIS AND PRODUCTION OF ALKENYL COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for producing an efficient alkenyl compound conveniently and inexpensively. SOLUTION: A first compound represented by formula (1) reacts with a second compound represented by formula (3), in the presence of amino acid, in solvent containing amine, in a range of 50-200°C, to produce an alkenyl compound represented by formula (A) [where R1 is hydrogen or an optionally substituted C1-C30 alkyl group, R2 is a carboxyl group or the like, R3 and R4 are hydrogen, an optionally substituted C1-C30 alkyl group or the like]. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0072; 0074-0079; 0081; 0082
(2018/09/20)
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- Pore Size Architecture of Hexagonal Mesoporous Carbon Nitride (HMCN) for Metal-Free Synthesis of p-Hydroxycinnamic Acid
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Abstract: The nanochannels of hexagonal mesoporous carbon nitride (HMCN) base catalytic materials were architected with diameter of 4.7, 5.9, and 7.1?nm using SBA-15 hard templates and these catalysts were represented as HMCN (4.7), HMCN (5.9), and HMCN (7.1), respectively. These materials were characterized by XRD, N2 sorption, FESEM, EDAX, HRTEM, FTIR and DR UV–Vis spectroscopy. The influence of HMCN catalysts with different pore sizes on p-hydroxycinnamic acid synthesis was investigated in metal/pyridine-free reaction conditions. The catalytic experimental results of HMCN (5.9) catalyst with optimum pore diameter of 5.9?nm showed an excellent catalytic performance of 94.5% p-hydroxybenzaldehyde conversion with 100% p-hydroxycinnamic acid selectivity within 60?min in comparison with other two catalysts, namely HMCN (4.7) and HMCN (7.1).
- Elamathi,Chandrasekar
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p. 1758 - 1767
(2018/04/05)
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- De novo biosynthesis of p-coumaric acid in E. Coli with a trans-Cinnamic Acid 4-Hydroxylase from the Amaryllidaceae Plant Lycoris aurea
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p-Coumaric acid is a commercially available phenolcarboxylic acid with a great number of important applications in the nutraceutical, pharmaceutical, material and chemical industries. p-Coumaric acid has been biosynthesized in some engineered microbes, but the potential of the plant CYP450-involved biosynthetic route has not investigated in Escherichia coli. In the present study, a novel trans-cinnamic acid 4-hydroxylase (C4H) encoding the LauC4H gene was isolated from Lycoris aurea (L’ Hér.) Herb via rapid amplification of cDNA ends. Then, N-terminal 28 amino acids of LauC4H were characterized, for the subcellular localization, at the endoplasmic reticulum membrane in protoplasts of Arabidopsis thaliana. In E. coli, LauC4H without the N-terminal membrane anchor region was functionally expressed when fused with the redox partner of A. thaliana cytochrome P450 enzyme (CYP450), and was verified to catalyze the trans-cinnamic acid to p-coumaric acid transformation by whole-cell bioconversion, HPLC detection and LC-MS analysis as well. Further, with phenylalanine ammonia-lyase 1 of A. thaliana, p-coumaric acid was de novo biosynthesized from glucose as the sole carbon source via the phenylalanine route in the recombinant E. coli cells. By regulating the level of intracellular NADPH, the production of p-coumaric acid was dramatically improved by 9.18-fold, and achieved with a titer of 156.09 μM in shake flasks. The recombinant cells harboring functional LauC4H afforded a promising chassis for biological production of p-coumaric acid, even other derivatives, via a plant CYP450-involved pathway.
- Li, Yikui,Li, Jie,Qian, Binbin,Cheng, Li,Xu, Sheng,Wang, Ren
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- Rhamnetin Glycosides from the Genus Spiraea
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Rhamnetin (7-O-methylquercetin,1) and its glycosides were found for the first time in the genus Spiraea (Rosaceae) during chromatographic studies of representatives from the subgenus Protospiraea. Leaves of S. salicifolia yielded1, rhamnetin-3-O-β-D-glucopyranoside (2), and two new flavonoids3and4that were identified by UV, IR, and NMR spectroscopy and mass spectrometry as rhamnetin-3-O-(6″-O-p-coumaroyl)-β-D-glucopyranoside (spiraearhamnin A,3) and rhamnetin-3-O-(6″-O-caffeoyl)-β-D-glucopyranoside (spiraearhamnin B,4). Leaves of S. betulifolia and S. betulifolia var. aemiliana afforded1and2and glycosides of kaempferol, quercetin, and isorhamnetin. Species of the subgenus Metaspiraea (S. alpina, S. chamaedryfolia, S. dahurica, S. hypericifolia, and S. media) did not contain1or its derivatives.
- Olennikov,Chirikova
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- Visible-light-enabled denitrative carboxylation of β-nitrostyrenes: A direct photocatalytic approach to cinnamic acids
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The first workable application of β-nitrostyrenes and CBr4 as coupling partners for a highly stereoselective synthesis of (E)-cinnamic acids under visible light photoredox catalysis is reported. The reaction involves a radical denitrative tribromomethylation/hydrolysis cascade to afford (E)-cinnamic acids in excellent yields at room temperature in a one-pot procedure. Moreover, the implementation of visible light as a clean and inexpensive energy source and CBr4 as the latent source of carboxylic groups makes the protocol reconcilable with the present day scenario of organic synthesis.
- Tripathi, Shubhangi,Yadav, Lal Dhar S.
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supporting information
p. 3765 - 3769
(2018/03/06)
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- Black goji as a potential source of natural color in a wide pH range
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Lycium ruthenicum Murr. is a traditional Chinese herb widely distributed in Tibet. The fruit, known as black goji, is popular in traditional Chinese medicine. The objective of this study was to investigate its anthocyanin profile (by HPLC coupled to PDA and MS detectors) and the colorimetric and spectrophotometric properties. Black goji extracts contained abundant petunidin derivatives, with cis and trans isomers of petunidin-3-p-coumaroyl-rutinoside-5-glucoside. The colorimetric and spectrophotometric traits of black goji anthocyanins were significantly impacted by solid-phase-extraction, pH, and acylation. MCX cartridge removed considerable polyphenolics from fruit extracts, but attenuated the saturation of color expression. Petunidin-3-trans-p-coumaroyl-rutinoside-5-glucoside contributed most of the color expression of the black goji extract, and showed superior stability compared to other extracts over time. Acylation strengthened the petunidin derivatives color retention, and enhanced the color intensity and stability. Black goji anthocyanins produced various vivid hues over wide ranges of pH, making them promising candidates for natural colorants.
- Tang, Peipei,Giusti, M. Monica
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p. 419 - 426
(2018/07/13)
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- Revisiting alkaline aerobic lignin oxidation
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Lignin conversion to renewable chemicals is a promising means to improve the economic viability of lignocellulosic biorefineries. Alkaline aerobic oxidation of lignin has long been employed for production of aromatic compounds such as vanillin and syringaldehyde, but this approach primarily focuses on condensed substrates such as Kraft lignin and lignosulfonates. Conversely, emerging lignocellulosic biorefinery schemes enable the production of more native-like, reactive lignin. Here, we revisit alkaline aerobic oxidation of highly reactive lignin substrates to understand the impact of reaction conditions and catalyst choice on product yield and distribution. The oxidation of native poplar lignin was studied as a function of temperature, NaOH loading, reaction time, and oxygen partial pressure. Besides vanillin and syringaldehyde, other oxidation products include acetosyringone and vanillic, syringic, and p-hydroxybenzoic acids. Reactions with vanillin and syringaldehyde indicated that these compounds are further oxidized to non-aromatic carboxylic acids during alkaline aerobic oxidation, with syringaldehyde being substantially more reactive than vanillin. The production of phenolic compounds from lignin is favored by high NaOH loadings and temperatures, but short reaction times, as the products degrade rapidly, which is further exacerbated by the presence of oxygen. Under optimal conditions, a phenolic monomer yield of 30 wt% was obtained from poplar lignin. Testing a range of catalysts showed that Cu-containing catalysts, such as CuSO4 and LaMn0.8Cu0.2O3, accelerate product formation; specifically, the catalyst does not increase the maximum yield, but expands the operating window in which high product yields are obtainable. We also demonstrate that other native and isolated lignin substrates that are significantly chemically modified are effectively converted to phenolic compounds. Finally, alkaline aerobic oxidation of native lignins was compared to nitrobenzene oxidation and reductive catalytic fractionation, as these methods constitute suitable benchmarks for lignin depolymerization. While nitrobenzene oxidation achieved a somewhat higher yield, similar monomer yields were obtained through RCF and alkaline aerobic oxidation, especially for lignins with a high guaiacyl- and/or p-hydroxyphenyl-content, as syringyl units are more unstable during oxidation. Overall, this study highlights the potential for aerobic lignin oxidation revisited on native-like lignin substrates.
- Schutyser, Wouter,Kruger, Jacob S.,Robinson, Allison M.,Katahira, Rui,Brandner, David G.,Cleveland, Nicholas S.,Mittal, Ashutosh,Peterson, Darren J.,Meilan, Richard,Román-Leshkov, Yuriy,Beckham, Gregg T.
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supporting information
p. 3828 - 3844
(2018/08/21)
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- Flavonoid glycosides from Sedum bulbiferum
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The MeOH extract from dried whole Sedum bulbiferum MAKINO (Crassulaceae) plants yielded 34 compounds, including six new flavonoid glycosides and 28 known compounds. The structures of new compounds were established using NMR, Mass spectroscopic analysis an
- Warashina, Tsutomu,Miyase, Toshio
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p. 1199 - 1204
(2017/12/26)
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- Palladium nanoparticles immobilized on amphiphilic and hyperbranched polymer-functionalized magnetic nanoparticles: An efficient semi-heterogeneous catalyst for Heck reaction
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To address the obstacles facing the use of palladium-based homogeneous and heterogeneous catalysts in C─C cross-coupling reactions, a novel semi-heterogeneous support was developed based on hyperbranched poly(ethylene glycol)-block-poly(citric acid)-functionalized Fe3O4 magnetic nanoparticles (Fe3O4@PCA-b-PEG). Because of the surface modification of the Fe3O4 nanoparticles with amphiphilic and hyperbranched polymers (PCA-b-PEG), these hybrid materials are not only soluble in a wide range of solvents (e.g. water, ethanol and dimethylformamide) but also are able to trap Pd2+ ions via complex formation of free carboxyl groups of the PCA dendrimer with metal ions. The reduction of trapped palladium ions in the dendritic shell of Fe3O4@PCA-b-PEG leads to immobilized palladium nanoparticles. The morphology and structural features of the catalyst were characterized using various microscopic and spectroscopic techniques. The catalyst was effectively used in the palladium-catalysed Mizoroki–Heck coupling reaction in water as a green solvent. In addition, the catalyst can be easily recovered from the reaction mixture by applying an external magnetic field and reused for more than ten consecutive cycles without much loss in activity, exhibiting an example of a sustainable and green methodology.
- Tabatabaei Rezaei, Seyed Jamal,Shamseddin, Azin,Ramazani, Ali,Mashhadi Malekzadeh, Asemeh,Azimzadeh Asiabi, Pegah
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- A Simple and straightforward synthesis of cinnamic acids and ylidene malononitriles via knoevenagel condensation employing dabco as catalyst
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An efficient method for the synthesis of substituted cinnamic acid and ylidene malanonitriles is developed via Knoevenagel condensation of aromatic aldehydes with malonic acid and malononitrile in the presence of catalytic amounts of DABCO. This method has many advantages, such as mild reaction conditions, excellent yields, short reaction times and no furthur purification required.
- Nagalakshmi,Diwakar,Govindh,Gopal Reddy,Venu,Bhargavi,Prasanna Devi,Murthy,Siddaiah
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p. 1561 - 1564
(2017/05/29)
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- Synthesis and antibacterial evaluation of novel 11-O-carbamoyl clarithromycin ketolides
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A series of novel 11-O-carbamoyl clarithromycin ketolides were designed, synthesized and evaluated for their in vitro antibacterial activity. The results showed that the majority of the target compounds displayed improved activity compared with references against erythromycin-resistant S. pneumoniae A22072 expressing the mef gene, S. pneumoniae B1 expressing the erm gene and S. pneumoniae AB11 expressing the mef and erm genes. In particular, compounds 9, 18, 19 and 22 showed the most potent activity against erythromycin-resistant S. pneumoniae A22072 with the MIC values of 0.5?μg/mL. Furthermore, compounds 11, 18, 19, 24 and 29 were also found to exhibit favorable antibacterial activity against erythromycin-susceptible S. pyogenes with the MIC values of 0.125–1?μg/mL, and moderate activity against erythromycin-susceptible S. aureus ATCC25923 and B. subtilis ATCC9372.
- Jia, Li,Yan, Mi,Shen, Yan,Qin, Yinhui,Qiang, Shengsheng,Ma, Shutao
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supporting information
p. 3693 - 3697
(2017/07/27)
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