- Antibacterial compounds from zanthoxylum rhetsa
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A new amide, zanthorhetsamide (1), along with nine known compounds (2-10) was isolated from the roots and stem barks of Zanthoxylum rhetsa. The structure was characterized by spectroscopic methods. In addition, the antibacterial activity of the isolates was evaluated. Dihydrochelerythrine (4) exhibited strong activity against methicillin-resistant Staphylococcus aureus SK1 and moderate activity against Escherichia coli TISTR 780 with MIC values of 8 and 16 μg/mL, respectively.
- Tantapakul, Cholpisut,Phakhodee, Wong,Ritthiwigrom, Thunwadee,Yossathera, Kulsiri,Deachathai, Suwanna,Laphookhieo, Surat
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- Homochiral Dodecanuclear Lanthanide "cage in Cage" for Enantioselective Separation
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It is extremely difficult to anticipate the structure and the stereochemistry of a complex, particularly when the ligand is flexible and the metal node adopts diverse coordination numbers. When trivalent lanthanides (LnIII) and enantiopure amino acid ligands are utilized as building blocks, self-assembly sometimes yields rare chiral polynuclear structures. In this study, an enantiopure carboxyl-functionalized amino acid-based ligand with C3 symmetry reacts with lanthanum cations to give a homochiral porous coordination cage, (Δ/λ)12-PCC-57. The dodecanuclear lanthanide cage has an unprecedented octahedral "cage-in-cage"framework. During the self-assembly, the chirality is transferred from the enantiopure ligand and fixed by the binuclear lanthanide cluster to give 12 metal centers that have either Δor λ homochiral stereochemistry. The cage exhibits excellent enantioselective separation of racemic alcohols, 2,3-dihydroquinazolinones, and multiple commercially available drugs. This finding exhibits a rare example of a multinuclear lanthanide complex with a dual-walled topology and homochirality. The highly ordered self-assembly and self-sorting of flexible amino acids and lanthanides shed light on the chiral transformation between different complicated artificial systems that mimic natural enzymes.
- Zhu, Chengfeng,Tang, Haitong,Yang, Keke,Fang, Yu,Wang, Kun-Yu,Xiao, Zhifeng,Wu, Xiang,Li, Yougui,Powell, Joshua A.,Zhou, Hong-Cai
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supporting information
p. 12560 - 12566
(2021/08/23)
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- C3 The symmetry contains a chiral ligand H3L of an amide bond. Preparation method and application
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The invention discloses C. 3 Chiral ligand H with symmetric amide bond3 L Relates to the technical field of material chemistry and chiral chemistry. The invention further provides the chiral ligand H. 3 L Preparation method and application thereof. The present invention has the advantage that the chiral ligand H of the present invention is a chiral ligand. 3 The L has a higher C. 3 The symmetric and flexible amide group enables coordination of the lanthanide metal ions with high coordination number and high oxygen affinity to be assembled into a novel structure-structure lanthanide metal chiral porous coordination cage. Moreover, the abundant chiral amide groups and amino acid residues on the ligand framework can be directly introduced into the synthesized lanthanide metal chiral porous coordination cage, thereby being beneficial to generating multiple chiral recognition sites and unique chiral microenvironments which mimic the biological enzyme binding pocket and further realize the purpose of high enantioselectivity separation of a series of chiral small molecule compounds.
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Paragraph 0067; 0111-0114
(2021/09/08)
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- Enantioselective Aminohydroxylation of Styrenyl Olefins Catalyzed by an Engineered Hemoprotein
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Chiral 1,2-amino alcohols are widely represented in biologically active compounds from neurotransmitters to antivirals. While many synthetic methods have been developed for accessing amino alcohols, the direct aminohydroxylation of alkenes to unprotected, enantioenriched amino alcohols remains a challenge. Using directed evolution, we have engineered a hemoprotein biocatalyst based on a thermostable cytochrome c that directly transforms alkenes to amino alcohols with high enantioselectivity (up to 2500 TTN and 90 % ee) under anaerobic conditions with O-pivaloylhydroxylamine as an aminating reagent. The reaction is proposed to proceed via a reactive iron-nitrogen species generated in the enzyme active site, enabling tuning of the catalyst's activity and selectivity by protein engineering.
- Cho, Inha,Prier, Christopher K.,Jia, Zhi-Jun,Zhang, Ruijie K.,G?rbe, Tamás,Arnold, Frances H.
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supporting information
p. 3138 - 3142
(2019/02/01)
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- Nitration-Peroxidation of Alkenes: A Selective Approach to β-Peroxyl Nitroalkanes
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Nitration-peroxidation of alkenes for the synthesis of β-peroxyl nitroalkanes has been developed by using tert-butyl nitrite and tert-butyl hydroperoxide. The method presents a new and selective difunctionalization of alkenes to introduce a nitro group and a peroxyl group across the double bonds of alkenes under mild conditions. A radical reaction pathway is proposed by experimental and theoretical studies.
- Chen, Yuanjin,Ma, Yangyang,Li, Liangkui,Jiang, Hao,Li, Zhiping
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p. 1480 - 1483
(2019/02/26)
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- Strengthening the Combination between Enzymes and Metals in Aqueous Medium: Concurrent Ruthenium-Catalyzed Nitrile Hydration - Asymmetric Ketone Bioreduction
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A dual ruthenium/ketoreductase catalytic system has been developed for the conversion of β-ketonitriles into optically active β-hydroxyamides through an unprecedented hydration/bioreduction cascade process in aqueous medium working in concurrent mode. The ketoreductase-mediated ketone reduction took place with exquisite stereoselectivity and it was simultaneous to the nitrile hydration promoted by the ruthenium catalyst. The overall transformation occurred: (i) employing commercially and readily available catalytic systems (ii) under mild reaction conditions, (iii) with high degree of conversion and excellent stereoselectivity, and (iv) without the need to isolate intermediates and with high final product yields. This genuine process demonstrates the benefits of combining metal and enzymatic catalysis to tackle the limitations arising from each field.
- Liardo, Elisa,González-Fernández, Rebeca,Ríos-Lombardía, Nicolás,Morís, Francisco,García-álvarez, Joaquín,Cadierno, Victorio,Crochet, Pascale,Rebolledo, Francisca,González-Sabín, Javier
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p. 4676 - 4682
(2018/09/25)
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- In silico prioritization, synthesis and in vitro evaluation of tembamide analogs for anti-HIV activity
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Background: High attrition rate in late drug discovery and development stages leads to financial loss to industries and Governments. Despite the global prevalence of HIV infection and lack of promising treatment for AIDS patients, there are only a few drugs approved for the management of infected patients. There is an urgent need to discover newer anti-HIV drugs with novel mechanism of action and with efforts to reduce attrition rate in early drug discovery stages. Objective: Prioritization of reported potential anti-HIV-1 leads according to their quantitative estimation of druglikeness (QED), carcinogenicity, mutagenicity, absorption, metabolism and toxic properties. Synthesis of analogs of the best lead and evaluation of their anti-HIV-1 activity is shown. Methods: In silico anti-HIV lead prioritization was performed on a set of known anti-HIV natural products in order to obtain a lead with better druglikeness and ADMET properties. Prioritized lead tembamide and its four analogs were synthesized and their anti-HIV-1 activity was evaluated. Results: Tembamide was found to be a lead with better QED, absorption and metabolism properties and with no carcinogenicity, mutagenicity and toxic potential. (+)-Tembamide is previously reported to show potent anti-HIV-1 activity against laboratory adapted strains HIV-1IIIB (X4, subtype B) and HIV-1Ada5 (R5, subtype B) in H9 cell line. It was observed during this study that synthesized tembamide and its four analogs were weakly active against primary isolates HIV-1UG070 (X4, subtype D) and HIV-1VB59 (R5, subtype C) in TZM-bl cell line. Conclusion: The results showed that there is scope for the improvement of activity of tembamide analogs to discover a potent anti-HIV compound.
- Gupta, Shiv,Kumar, Sanjay,Jariwala, Nisha,Bhadane, Deepali,Bhutani, Kamlesh Kumar,Kulkarni, Smita,Singh, Inder Pal
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p. 1455 - 1464
(2017/12/28)
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- Chiral metal?Organic framework as a platform for cooperative catalysis in asymmetric cyanosilylation of aldehydes
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In this work, we demonstrate cooperative asymmetric catalysis by a metal?organic framework (MOF) as exemplified in the context of catalyzing cyanation of aldehydes with a VO(salen)-MOF, which after oxidation affords remarkably increased stereoselectivity (up to >99% ee) compared to the homogeneous VO(salen) counterpart as a result of the pairs of VO(salen) units in close proximity within its open channels. The cooperative asymmetric catalysis has been evidenced by the significantly decreased stereoselectivity and activity when one VO(salen) in such pairs of VO(salen) units is replaced with one Cu(salen), which results in blocking the VO?VO synergistic pathway while prompting unimolecular activation of substrates. The heterogeneous nature of VO(salen)-MOF has been verified by the fact that it can be easily recycled and reused without significant loss of catalytic activity and enantioselectivity, and its practical utility as asymmetric cyanation catalysist has been illustrated in the gram-scale synthesis of the antiviral natural products (R)- and (S)-enantiomers of tembamide. Our work therefore advances chiral MOF as an attractive platform for cooperative asymmetric catalysis in a variety of syntheses.
- Zhu, Chengfeng,Xia, Qingchun,Chen, Xu,Liu, Yan,Du, Xia,Cui, Yong
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p. 7590 - 7596
(2018/05/23)
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- Anti-inflammatory alkaloid glycoside and quinoline alkaloid derivates from the stems of Clausena lansium
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Six new alkaloid glycosides, Clausenasides A-F (1-6), along with two new quinoline alkaloids, Clausenasides G-H (7-8), and ten known compounds (9-18) were obtained from the stems of C. lansium. The structures of the new compounds were elucidated on the basis of their spectroscopic analysis, and the absolute configurations of 1, 2, 3 and 7 were confirmed by Mosher's method, CD and ECD spectra, respectively. Compounds 4, 6, 9, 17, and 18 showed moderate inhibitory effects on LPS-induced NO production in murine microglial BV2 cells (IC50 values 10 μM).
- Liu, Jie,Li, Chuang-Jun,Ni, Lin,Yang, Jing-Zhi,Li, Li,Zang, Cai-Xia,Bao, Xiu-Qi,Zhang, Dan,Zhang, Dong-Ming
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p. 80553 - 80560
(2015/10/05)
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- Enantioselective Henry and aza-Henry reaction in the synthesis of (R)-tembamide using efficient, recyclable polymeric CuII complexes as catalyst
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Chiral copper(II) polymeric [H4]salen (salen=bis[(salicylidene) ethylenediaminato]) complexes CuII-1-3 were generated in situ and used as efficient catalysts in the asymmetric Henry and aza-Henry reaction of various aromatic and alip
- Das, Anjan,Choudhary, Manoj K.,Kureshy, Rukhsana I.,Roy, Tamal,Khan, Noor-Ul H.,Abdi, Sayed H.R.,Bajaj, Hari C.
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p. 1138 - 1146
(2014/10/16)
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- One-pot combination of enzyme and Pd nanoparticle catalysis for the synthesis of enantiomerically pure 1,2-amino alcohols
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One-pot combinations of sequential catalytic reactions can offer practical and ecological advantages over classical multi-step synthesis schemes. In this context, the integration of enzymatic and chemo-catalytic transformations holds particular potential for efficient and selective reaction sequences that would not be possible using either method alone. Here, we report the one-pot combination of alcohol dehydrogenase-catalysed asymmetric reduction of 2-azido ketones and Pd nanoparticle-catalysed hydrogenation of the resulting azido alcohols, which gives access to both enantiomers of aromatic 1,2-amino alcohols in high yields and excellent optical purity (ee >99%). Furthermore, we demonstrate the incorporation of an upstream azidolysis and a downstream acylation step into the one-pot system, thus establishing a highly integrated synthesis of the antiviral natural product (S)-tembamide in 73% yield (ee >99%) over 4 steps. Avoiding the purification and isolation of intermediates in this synthetic sequence leads to an unprecedentedly low ecological footprint, as quantified by the E-factor and solvent demand.
- Schrittwieser, Joerg H.,Coccia, Francesca,Kara, Selin,Grischek, Barbara,Kroutil, Wolfgang,D'Alessandro, Nicola,Hollmann, Frank
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p. 3318 - 3331
(2013/12/04)
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- Synthesis of (R)-tembamide and (R)-aegeline via asymmetric transfer hydrogenation in water
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The synthesis of (R)-tembamide and (R)-aegeline via asymmetric transfer hydrogenation involving enantioenriched monosulfonamide-RhCp a - complex in aqueous sodium formate as hydride donor is described.
- Cortez, Norma A.,Aguirre, Gerardo,Parra-Hake, Miguel,Somanathan, Ratnasamy
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p. 1297 - 1302
(2013/11/19)
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- Catalytic asymmetric hydrogenation of N-Boc-imidazoles and oxazoles
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Substituted imidazoles and oxazoles were respectively hydrogenated into the corresponding chiral imidazolines and oxazolines (up to 99% ee). The highly enantioselective hydrogenation was achieved by using the chiral ruthenium catalyst, which is generated
- Kuwano, Ryoichi,Kameyama, Nao,Ikeda, Ryuhei
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p. 7312 - 7315
(2011/06/24)
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- Asymmetric transfer hydrogenation of 2-tosyloxy-1-(4-hydroxyphenyl)ethanone derivatives: synthesis of (R)-tembamide, (R)-aegeline, (R)-octopamine, and (R)-denopamine
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Catalytic transfer hydrogenation of 2-tosyloxy-1-(4-hydroxyphenyl)ethanone derivatives leads to efficient synthesis of β-adrenergic agonists, (R)-tembamide, (R)-aegeline, (R)-octopamine, and (R)-denopamine.
- Lee, Do-Min,Lee, Jong-Cheol,Jeong, Nakcheol,Lee, Kee-In
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p. 2662 - 2667
(2008/09/16)
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- Binolam-AlCl: A two-centre catalyst for the synthesis of enantioenriched cyanohydrin O-phosphates
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The enantioselective synthesis of cyanohydrin O-phosphates by using in situ generated bifunctional catalysts (R)- or (S)-3,3′-bis(diethylaminomethyl) -1, 1′-binaphthol-aluminium chloride (binolam-AlCl) is reported. The reaction, which can be described as an overall cyano-O-phosphorylation of aldehydes, has a wide scope and applicability. Evidence is also provided, including ab initio and DFT calculations, in support of supported by the Lewis acid/Bronsted base (LABB) dual role of the catalyst in inducing first the key enantioselective hydrocyanation, which is then followed by O-phosphorylation. A brief screening of the synthetic usefulness of the resulting cyanohydrin O-phosphates unveiles some interesting applications. Among them, chemoselective hydrolysis, reduction and palladium-catalysed nucleophilic allyl substitution, thereby leading to enantiomerically enriched α-O-phosphorylated α-hydroxy esters, β-amino alcohols and γ-cyanoallyl alcohols, respectively. Naturally occurring (-)-tembamide and (-)-aegeline are synthesised accordingly.
- Baeza, Alcjandro,Najera, Carmen,Sansano, Jose M.,Saa, Jose M.
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p. 3849 - 3862
(2007/10/03)
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- Chemoenzymatic synthesis of (R)- and (S)-tembamide, aegeline and denopamine by a one-pot lipase resolution protocol
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An efficient synthesis of optically active β-azido alcohols from their ketoazides by a one-pot reduction and an in situ lipase resolution protocol is described. The synthetic utility of this procedure has been illustrated by its application in the practic
- Kamal, Ahmed,Shaik, Ahmad Ali,Sandbhor, Mahendra,Malik, M. Shaheer
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p. 3939 - 3944
(2007/10/03)
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- Short asymmetric syntheses of bioactive β-aryl ethanolamine derivatives via the highly diastereoselective delta lactol oxy-Michael addition
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Short, stereoselective and efficient total syntheses of the bioactive β-aryl ethanolamine derivatives (R)-tembamide, (R)-aegeline and (R)-pronethalol have been achieved using the highly diastereoselective oxy-Michael addition of 'naked' delta lactol anion
- Buchanan, David J.,Dixon, Darren J.,Scott, Mark S.,Laine, Dramane I.
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p. 195 - 197
(2007/10/03)
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- Application of optically active 1,2-diol monotosylates for synthesis of β-azido and β-amino alcohols with very high enantiomeric purity. Synthesis of enantiopure (R)-octopamine, (R)-tembamide and (R)-aegeline
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A very convenient and highly efficient synthesis of near enantiopure β-azido and β-amino alcohols including biologically active substances such as (R)-octopamine, (R)-tembamide and (R)-aegeline from optically active 1,2-diol monotosylates is reported.
- Tae Cho, Byung,Kyu Kang, Sang,Hye Shin, Sung
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p. 1209 - 1217
(2007/10/03)
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- Stereoselective synthesis of (R)-(-)-denopamine, (R)-(-)-tembamide and (R)-(-)-aegeline via asymmetric reduction of azidoketones by Daucus carota in aqueous medium
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A simple and efficient stereoselective synthesis of (R)-denopamine and other naturally occurring hydroxy amides from optically active (R)-2-azido-1-arylethanols, is described for the first time via reduction of the corresponding α-azidoarylketones with en
- Yadav,Reddy,Nanda,Rao
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p. 3381 - 3385
(2007/10/03)
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- Synthetic applications of optically active cyanohydrins. Enantioselective syntheses of the hydroxyamides tembamide and aegeline, the cardiac drug denopamine, and some analogues of the bronchodilator salbutamol
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The natural hydroxyamides, (-)-tembamide and (-)-aegeline, and the cardiac drug (-) -denopamine have been prepared in homochiral form in good overall yield (>65%) from para - methoxy or para-allyloxybenzaldehyde by synthetic sequences involving entantioselective hydrocyanation of the aldehydes. Similar chemistry has been used to prepare analogues of the bronchodilator (-)-salbutamol both in high yield and with good enantiomeric excess.
- Brown, Roger F. C.,Donohue, Andrew C.,Roy Jackson,McCarthy, Tom D.
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p. 13739 - 13752
(2007/10/02)
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- The Synthesis of Homochiral Naturally Occurring Hydroxy Amides
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The chiral naturally occurring hydroxy amides, (-)-tembamide and (-)-aegeline has been synthesised in two steps from (R)-2-hydroxy-2-(4-methoxyphenyl)acetonitrile
- Brown, Roger F. C.,Jackson, W. Roy,McCarthy, Tom D.
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p. 205 - 206
(2007/10/02)
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- SYNTHESES OF NATURAL HYDROXYAMIDES USING TRIMETHYLSILYL CYANIDE
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New syntheses of tembamide (1), aegeline (2), and other hydroxyamides, using trimethylsilyl cyanide, are described.
- Somanathan, Ratnasamy,Aguilar, Hugo R.,Ventura, Gmo. Rodriguez
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p. 273 - 280
(2007/10/02)
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- Carbon-13 NMR Spectra of Tembamide, Aegeline and Related Amides
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Carbon-13 NMR spectral studies of tembamide (1) and aegeline (2), constituents of Fagara hyemalis and Aegle marmelos respectively, and a series of their structurally related amides (3-13) have been carried out.The assignment of the resonances of two related dimers are also reported.The assignment of the various resonances were made by considering the changes in chemical shifts produced by the change of substituents and also by using 1, 13 and a related compound as model compounds.
- Patra, Amarendra,Mitra, Alok K.,Ghosh, Arundhati,Mukhopadhyay, Prabir K.
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