- Favipiravir-Based Ionic Liquids as Potent Antiviral Drugs for Oral Delivery: Synthesis, Solubility, and Pharmacokinetic Evaluation
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Coronavirus disease 2019 (COVID-19) has spread across the world, and no specific antiviral drugs have yet been approved to combat this disease. Favipiravir (FAV) is an antiviral drug that is currently in clinical trials for use against COVID-19. However, the delivery of FAV is challenging because of its limited solubility, and its formulation is difficult with common organic solvents and water. To address these issues, four FAV ionic liquids (FAV-ILs) were synthesized as potent antiviral prodrugs and were fully characterized by nuclear magnetic resonance (NMR) spectroscopy, Fourier-transform infrared (FT-IR) spectrometry, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC). The aqueous solubility and in vivo pharmacokinetic properties of the FAV-ILs were also evaluated. The FAV-ILs exhibited improved aqueous solubility by 78 to 125 orders of magnitude when compared with that of free FAV. Upon oral dosing in mice, the absolute bioavailability of the β-alanine ethyl ester FAV formulation was increased 1.9-fold compared with that of the control FAV formulation. The peak blood concentration, elimination half-life, and mean absorption time of FAV were also increased by 1.5-, 2.0-, and 1.5-fold, respectively, compared with the control. Furthermore, the FAV in the FAV-ILs exhibited significantly different biodistribution compared with the control FAV formulation. Interestingly, drug accumulation in the lungs and liver was improved 1.5-fold and 1.3-fold, respectively, compared with the control FAV formulation. These results indicate that the use of ILs exhibits potential as a simple, scalable strategy to improve the solubility and oral absorption of hydrophobic drugs, such as FAV.
- Moshikur, Rahman Md,Ali, Md. Korban,Wakabayashi, Rie,Moniruzzaman, Muhammad,Goto, Masahiro
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p. 3108 - 3115
(2021/07/31)
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- Stereospecific Synthesis of 3,4-Dihydro-2 H-naphtho-1,4-oxazin-2-ones by Unification of Benzoxepine-4-carboxylates with Chiral Amino Acid Ethyl Esters
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A novel and efficient stereocontrolled method has been developed for the preparation of chiral 3,4-dihydro-2H-naphtho[1,2-b][1,4]oxazin-2-ones by the reaction of benzoxepine-4-carboxylates with chiral amino acid ethyl esters for the first time. The chiral 3,4-dihydro-2H-naphtho-1,4-oxazinones have been achieved in one step by the formation of C-N, C-C, and C-O bonds.
- Bhimapaka, China Raju,Kasagani, Veera Prasad,Kurma, Siva Hariprasad
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supporting information
p. 2976 - 2983
(2020/03/23)
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- Design, synthesis, and biological evaluation of novel stachydrine derivatives as potent neuroprotective agents for cerebral ischemic stroke
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Stachydrine is a natural product with multiple protective biological activities, including those involved in preventing cancer, ischemia, and cardiovascular disease. However, its use has been limited by low bioavailability and unsatisfactory efficacy. To address this problem, a series of stachydrine derivatives (A1/A2/A3/A4/B1/B2/B3/B4) were designed and synthesized, and biological studies were carried out in vitro and in vivo. When compared with stachydrine, Compound B1 exhibited better neuroprotective effects in vitro, and significantly reduced infarction size in the model of the middle cerebral artery occlusion rat model. Therefore, Compound B1 was selected for further research on ischemic stroke. [Figure not available: see fulltext.].
- Zhang, Liang,Li, Feng,Hou, Chenhui,Zhu, Sifeng,Zhong, Lili,Zhao, Jianchun,Song, Cai,Li, Wenbao
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p. 2529 - 2542
(2020/05/25)
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- Ionic liquids with methotrexate moieties as a potential anticancer prodrug: Synthesis, characterization and solubility evaluation
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The technological utility of active pharmaceutical ingredients (APIs) is enormously improved when they are converted into ionic liquids (ILs). API-ILs possess better aqueous solubility and thermal stability than that of solid-state salt or crystalline drugs. However, many such API-ILs are not biocompatible or biodegradable. In the current study, we synthesized a series of IL-APIs using methotrexate (MTX), a potential anticancer prodrug, and biocompatible IL-forming cations (choline and amino acid esters). The MTX-IL moieties were characterized through 1H NMR, FTIR, p-XRD, DSC and thermogravimetric analysis. The solubility of the MTX-ILs was evaluated in simulated body fluids (phosphate-buffered saline, simulated gastric, and simulated intestinal fluids). An assessment of the in vitro antitumor activity of the MTX-ILs in a mammalian cell line (HeLa cells) was used to evaluate their cytotoxicity. The MTX-ILs showed aqueous solubility at least 5000 times higher than that of free MTX and two orders of magnitude higher compared with that of a sodium salt of MTX in both water and simulated body fluids. Importantly, a proline ethyl ester MTX prodrug showed similar solubility as the MTX sodium salt but it provided improved in vitro antitumor activity. These results clearly suggest that the newly synthesized API-ILs represent promising potential drug formulations.
- Moshikur, Rahman Md.,Chowdhury, Md. Raihan,Wakabayashi, Rie,Tahara, Yoshiro,Moniruzzaman, Muhammad,Goto, Masahiro
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p. 226 - 233
(2019/01/23)
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- Characterization and cytotoxicity evaluation of biocompatible amino acid esters used to convert salicylic acid into ionic liquids
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The technological utility of active pharmaceutical ingredients (APIs) is greatly enhanced when they are transformed into ionic liquids (ILs). API-ILs have better solubility, thermal stability, and the efficacy in topical delivery than solid or crystalline drugs. However, toxicological issue of API-ILs is the main challenge for their application in drug delivery. To address this issue, 11 amino acid esters (AAEs) were synthesized and investigated as biocompatible counter cations for the poorly water-soluble drug salicylic acid (Sal) to form Sal-ILs. The AAEs were characterized using 1H and 13C NMR, FTIR, elemental, and thermogravimetric analyses. The cytotoxicities of the AAE cations, Sal-ILs, and free Sal were investigated using mammalian cell lines (L929 and HeLa). The toxicities of the AAE cations greatly increased with inclusion of long alkyl chains, sulfur, and aromatic rings in the side groups of the cations. Ethyl esters of alanine, aspartic acid, and proline were selected as a low cytotoxic AAE. The cytotoxicities of the Sal-ILs drastically increased compared with the AAEs on incorporation of Sal into the cations, and were comparable to that of free Sal. Interestingly, the water miscibilities of the Sal-ILs were higher than that of free Sal, and the Sal-ILs were miscible with water at any ratio. A skin permeation study showed that the Sal-ILs penetrated through skin faster than the Sal sodium salt. These results suggest that AAEs could be used in biomedical applications to eliminate the use of traditional toxic solvents for transdermal delivery of poorly water-soluble drugs.
- Moshikur, Rahman Md.,Chowdhury, Md. Raihan,Wakabayashi, Rie,Tahara, Yoshiro,Moniruzzaman, Muhammad,Goto, Masahiro
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- A synthesis method of the dried meat ammonia is mellow L -
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The invention discloses an L-prolinol synthetic method. The method comprises the following steps that 1, ethyl alcohol is added in a reaction kettle, thionyl chloride is dropwise added at 10-15 DEG C, then, L-prolinol is added, the temperature is increased to 40 DEG C, a heat-preservation reaction is carried out for 10-12 h, the mixture is concentrated to be thick liquid after the reaction is finished, ethyl acetate is added for dissolution, the pH value is adjusted through triethylamine to be 7-8, and salt is filtered away to obtain L-proline ethyl ester; 2, the L-proline ethyl ester is in a methyl alcohol system, lithium chloride is added at 5-10 DEG C, the sodium borohydride is added many times, a heat-preservation reaction is carried out at 20-25 DEG C for 2-2.5 h, hydrochloric acid is added, heat-preservation hydrolysis is carried out for 2 h, methyl alcohol is recycled, the pH value is adjusted through 25% sodium hydroxide to be 12, a product is extracted through dichloromethane, anhydrous sodium sulfate drying is carried out, and filtering is carried out; 3, dichloromethane is recycled from mother liquid at 30-40 DEG C and normal pressure, oily matter is obtained, pressure reduction and distillation are carried out, and therefore the pure L-prolinol is obtained. According to the L-prolinol synthetic method, the reaction temperature is mild, the safety coefficient is low, no solid waste is produced, and environmental protection is achieved.
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Paragraph 0016-0019
(2018/07/06)
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- The reactions of α-amino acids and α-amino acid esters with high valent transition metal halides: synthesis of coordination complexes, activation processes and stabilization of α-ammonium acylchloride cations
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Titanium tetrachloride smoothly reacted with a selection of α-amino acids (aaH) in CH2Cl2 affording yellow to orange solid coordination compounds, 1a-d, in 70-78% yields. The salts [NHEt3][TiCl4(aa)], 2a-b, were obtained from TiCl4/aaH/NEt3 (aa = l-phenylalanine, N,N-dimethylphenylalanine), in 60-65% yields. The complex , 3, was isolated from the reaction of l-proline with NbCl5/NHiPr2, performed in CH2Cl2 at room temperature. The X-ray structure of 3 features a bridging (E)-1,2-bis(3,4-dihydro-2H-pyrrol-5-yl)ethene-1,2-diolate ligand, resulting from the unprecedented C-C coupling between two proline units. Unusually stable α-ammonium acyl chlorides were prepared by the reactions of PCl5/MCln (MCln = NbCl5, WCl6) with l-proline, N,N-dimethylphenylalanine, sarcosine and l-methionine. MX5 (M = Nb, Ta; X = F, Cl) reacted with l-leucine methylester and l-proline ethylester to give ionic coordination compounds, [MX4L2][MX6] (M = Nb, L = Me2CHCH2CH(NH2)CO2Me, X = F, 9; Cl, 11a; M = Nb, X = Cl, , 11c; Ta, 11d), in moderate to good yields. [NbCl5(Me2CHCH2CHNH3CO2Me)][NbCl6], 12, was isolated as a co-product of the reaction of NbCl5 with l-leucine isopropylester, and crystallographically characterized. The reaction of NbCl5 with l-serine isopropylester afforded NbCl3(OCH2CHNHCO2iPr), 13, in 66% yield. The activation of the ester O-R bond was observed in the reactions of l-leucine methyl ester with NbF5 and l-proline ethyl ester with MBr5 (M = Nb, Ta), these reactions proceeding with the release of EtF and EtBr, respectively. All the metal products were characterized by analytical and spectroscopic methods, while DFT calculations were carried out in order to provide insight into the structural and mechanistic aspects.
- Biancalana, Lorenzo,Bortoluzzi, Marco,Ferretti, Eleonora,Hayatifar, Mohammad,Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
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p. 10158 - 10174
(2017/02/15)
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- Stereochemistry and conformation of skyllamycin, a non-ribosomally synthesized peptide from streptomyces sp. Acta 2897
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Skyllamycin is a non-ribosomally synthesized cyclic depsipeptide from Streptomyces sp. Acta 2897 that inhibits PDGF-signaling. The peptide scaffold contains an N-terminal cinnamoyl moiety, a β-methylation of aspartic acid, three β-hydroxylated amino acids and one rarely occurring α-hydroxy glycine. With the exception of α-hydroxy glycine, the stereochemistry of the amino acids was assigned by comparison to synthetic reference amino acids applying chiral GC-MS and Marfey-HPLC analysis. The stereochemistry of α-hydroxy glycine, which is unstable under basic and acidic conditions, was determined by conformational analysis, employing a combination of data from NOESY-NMR spectroscopy, simulated annealing and free MD simulations. The simulation procedures were applied for both R- and S-configured α-hydroxy glycine of the skyllamycin structure and compared to the NOESY data. Both methods, simulated annealing and free MD simulations independently support S-configured α-hydroxy glycine thus enabling the assignment of all stereocenters in the structure of skyllamycin and devising the role of two-component flavin dependent monooxygenase (Sky39) as S-selective.
- Schubert, Vivien,Di Meo, Florent,Saaidi, Pierre-Loic,Bartoschek, Stefan,Fiedler, Hans-Peter,Trouillas, Patrick,Suessmuth, Roderich D.
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p. 4948 - 4955
(2014/05/06)
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- Catalytic asymmetric aldol-type reaction of zinc enolate equivalent of amides
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Treatment of phenyl isocyanate with bis(iodozincio)methane gave a zinciomethylenated product, which acts as an amide-enoate equivalent. It did not react with an aldehyde efficiently, but gave the corresponding adduct in good yield in the presence of an aminoalcohol. Use of a catalytic amount of chiral aminoalcohol led the process to the catalytic asymmetric Aldol-type reaction.
- Haraguchi, Ryosuke,Matsubara, Seijiro
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supporting information
p. 3378 - 3380
(2013/07/26)
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- Preparation of l-proline based aeruginosin 298-A analogs: Optimization of the P1-moiety
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Aeruginosins are a family of naturally occurring oligopeptides that share a common bicyclic amino acid core structure. Many compounds in the family are inhibitors of serine proteases, such as thrombin and trypsin. Thrombin is an important enzyme in the bl
- Wang, Guijun,Goyal, Navneet,Hopkinson, Branden
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supporting information; experimental part
p. 3798 - 3803
(2010/02/28)
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- Synthesis and properties of novel chiral ionic liquids from L-proline
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A novel class of chiral ionic liquids with chiral cations directly derived from natural l-proline has been synthesized and their physical properties such as melting point, thermal degradation, and specific rotation have been characterized. Further, their potential use in chiral recognition was demonstrated by studying interactions with racemic Mosher's acid salt. CSIRO 2008.
- Gao, Hong-Shuai,Hu, Zhi-Guo,Wang, Jian-Ji,Qiu, Zhao-Fa,Fan, Feng-Qiu
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p. 521 - 525
(2008/12/20)
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- Synthesis of quinolactacide via an acyl migration reaction and dehydrogenation with manganese dioxide, and its insecticidal activities
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Quinolactacide isolated from Penicillium citrinum F 1539 was synthesized and evaluated for its insecticidal activities. The key steps of the total synthesis were an acyl migration reaction of the enol ester intermediate and dehydrogenation of tetrahydroqu
- Abe, Masaki,Imai, Tetsuya,Ishii, Naoki,Usui, Makio
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p. 303 - 306
(2008/02/10)
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- Synthesis of diketopiperazines containing prolinyl unit - Cyclo(L-prolinyl-L-leucine), cyclo(L-prolinyl-L-isoleucine) and cyclo(L-tryptophyl-L-proline)
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Diketopiperazines cyclo(L-prolinyl-L-isoleucine) 4a, cyclo(L-prolinyl-L-leucine) 4b and cyclo(L-tryptophyl-L-proline) 6 were prepared from their respective suitably protected amino acid derivatives by standard peptide chemistry. Cyclo(L-(4-hydroxyprolinyl)-L-phenylalanine) 3, 4a and cyclo(L-prolinyl-L-tyrosine) 5 were tested for their antibacterial activity.
- Jhaumeer-Laulloo,Khodabocus,Jugoo,Jheengut,Sobha
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p. 765 - 768
(2007/10/03)
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- Asymmetric synthesis of (R)-(+)-etomoxir
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An asymmetric synthesis of etomoxir 1, involving bromolactonization by using (S)-(-)-proline as a chiral auxiliary, is reported.
- Jew, Sang-Sup,Kim, Hyung-Ook,Jeong, Byeong-Seon,Park, Hyeung-Geun
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p. 1187 - 1192
(2007/10/03)
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- LARGE SCALE PREPARATION OF VERSATILE CHIRAL AUXILIARIES DERIVED FROM (S)-PROLINE
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The synthesis of a variety of enantiomerically pure chiral auxiliaries based on (S)-proline and bearing sterically demanding side chains at the pyrrolidine moiety, such as the secondary amines (S)-3,5 and 7 and the hydrazines (S)-6, is described on a molar scale.As key step, the Grignard or RLi addition to the N-benzylated proline ester (S)-1 is used.
- Enders, Dieter,Kipphardt, Helmut,Gerdes, Peter,Brena-Valle, Leonardo J.,Bhushan, Vidya
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p. 691 - 704
(2007/10/02)
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