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1.
H. Dronia U. Gruß G. Hägele T. Friedrich H. Weiss 《Journal of computer-aided molecular design》1996,10(2):100-106
Summary The structural and electronic properties of fluorinated 1-N-arylamino-1-arylmethanephosphonic acid esters were studied and related to the inhibitory effects on NADH:ubiquinone oxidoreductase (complex I). Electrostatic potential surfaces, dipole moments and molecular geometries were analysed. Based on the conformational analysis and the electronic parameters, a simple model for the active site of the fluorinated 1-N-arylamino-1-arylmethanephosphonic acid esters was developed, explaining the inhibitory power. The strongest inhibition effects were found for the 1-(N-4-trifluoromethoxyphenyl)-amino-1-phenylmethanephosphonic acid diethyl ester 1bab. 相似文献
2.
Csaba Petotilde Gyula Batta Zoltán Györgydeák Ferenc Sztaricskai 《Journal of carbohydrate chemistry》2013,32(4):465-483
Abstract 1,3-Dipolar cycloaddition of the acetylated 1,2-trans- and 1,2-cis-cellobiosyl, -lactosyl, -maltosyl, and -melibiosyl azides with various acetylenedicarboxylic acid esters gave the corresponding 1-N-glycobiosyl-1,2,3-triazoles (1a,b,c-8a,b,c) which have been used as glycosyl donors for the synthesis of oligosaccharides (15-17) and an anthracycline type antibiotic (18). 相似文献
3.
Susana Dias Lucas Amélia Pilar Rauter Josef Schneider Hans Peter Wessel 《Journal of carbohydrate chemistry》2013,32(7-8):431-446
Starting from d-xylose, 2,4-anhydro-5-N-(tert-butoxycarbonyl)amino-5-deoxy-3-fluoro-d-arabinonic acid 11 was synthesized over 10 steps including ring contraction, fluorination, and ester hydrolysis. Bromine oxidation of d-xylose followed by benzylidenation in a one-pot procedure led to a ca. 1:1 mixture of lactone 3 and 2,4;3,5-dibenzylidene xylonic acid (4) as by-product. For the synthesis of the d-xylo derivative 24, the chosen starting material was 1,2-O-isopropylidene-α-d-xylofuranose. A total of 14 steps including epimerization, ring contraction, fluorination, and saponification led to the desired fluoro-oxetane δ-amino acid 24. Hydrolysis of the 3-fluoro-oxetane δ-amino esters 10 and 23 by means of LiOH was successful in agreement with the results previously reported for similar 3-methoxy oxetanes, whereas chemical hydrolysis was not possible for 3-hydroxy derivatives. 相似文献
4.
Two new sucrose esters, β-D-(1-O-acetyl-3,6-O-trans-diferuloyl)fructofuranosyl-α-D-2′-O-acetylglucopyranoside (1) and β-D-(1-O-acetyl-3-O-cis-feruloyl-6-O-trans-feruloyl)fructofuranosyl-α-D-2′,4′,6′-O-triacetylglucopyranoside (2), together with four known sucrose esters (3–6) have been isolated from the rhizome of Sparganium stoloniferum Buch.-Ham. Their structures were elucidated by physical and chemical evidence and spectral analysis. 相似文献
5.
Fabrice Burel Jean-Pierre Couvercelle Claude Bunel Jean-Marc Saiter 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(6):1091-1102
Abstract A series of α-n-alkyl acrylic acid monomers was synthesized and homopolymerized by a radical route. Methylation of polyacids using diazomethane led to the corresponding methyl esters and allowed physicochemical analysis. The thermal stability of polyacids and polymethyl esters is insensitive to the nature of the alkyl group and to the molecular weight. The glass transition temperature, T g, classically decreases with increases in alkyl group length such as alkyl polymethacrylates. Molecular weight has a drastic influence on T g for short alkyl groups. 相似文献
6.
Minas P. Georgiadis Violetta Constantinou-Kokotou George Kokotos 《Journal of carbohydrate chemistry》2013,32(5):739-748
ABSTRACT 6′-N derivatives of neamine with alanine, phenylalanine and lysine were synthesized either using an active esters method in one step under controlled conditions, or using a mixed anhydride method after blocking every functional group of neamine and leaving the 6′-amino group free to react. Similarly N,N′-diamino acid and monoamino acid derivatives of 2-deoxystreptamine were synthesized. 相似文献
7.
High-Performance Liquid Chromatographic Behavior of 2-,4- and 6-Hydroxylated Bile Acid Stereoisomers
《液相色谱法及相关技术杂志》2012,35(13):2527-2539
Abstract High-performance liquid chromatographic behavior has been investigated for 40 stereoisomeric 2-, 4- and 6-hydroxylated bile acids, most of which possess a vicinal glycol structure, as their 4-nitrophthalimidomethyl (NPM) ester derivatives on a reversed-phase column using methanol-water systems as a mobile phase. The bile acid NPM esters were further derivatized to the so-called “mixed” acetonide-NPM esters, whereby the stereochemical relationships (α, α-and β,β-cis, diaxial trans or diequatorial trans) of 2,3-, 3,4-and 6,7-diol groups in the molecules were reflected to changes in the capacity factors of bile acids. 相似文献
8.
Boguslawa Piekarska-Bartoszewicz Andrzej Tcmeriusz 《Journal of carbohydrate chemistry》2013,32(7):913-921
Abstract Amino acid methyl, ethyl or benzyl esters have been used as amination agents in reaction with methyl 3,4,6-tri-O-acetyl-2-deoxy-2-(4-nitrophenoxycarbonylamino)-β-D-glucopyranoside (1). Fourteen new ureido sugars, derivatives of 2-amino-2-deoxy-D-glucopyranoside and glycine, L-alanine, L-valine, L-leucine, L-phenylalanine, L-pro-line, L-aspartic acid and L-glutamic acid were obtained. 相似文献
9.
Li-juan Yang Xiao-dong Yang Shu Yang Jing-feng Zhao Hong-bin Zhang Liang Li 《Chemistry of Natural Compounds》2006,42(6):649-651
Two new benzoyl esters of glucose 1-O-(E)-4′-methoxybenzoyl-β-D-glucopyranose (1) and 1-O-(E)-4′-methoxybenzoyl-β-D-gluconic acid (2) were isolated from Lagotis yunnanensis, together with six previously known iridoid glucosides. The structures of these compounds were elucidated on the basis of
spectral analysis, including 2D NMR spectroscopy.
Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 529–530, November–December, 2006. 相似文献
10.
Several heterocyclic acetic acids and esters were synthesized by allowing the appropriate thiourea, ethylenethiourea or trimethylenethiourea to react with 4-chloroacetoacetic esters, followed by acid hydrolysis to the hydrochlorides of the free acids. Both esters and acids of 2-aminothiazole-4-acetic acid, 5,6-dihydro-imidazo[2,1-b]thiazole-3-acetic acid and 6,7-dihydro-5H-thiazolo[3,2-c]pyrimidine-3-acetic acid were obtained. 相似文献
11.
Palladium-catalyzed hydrostannylation of alkynyl esters in benzene at room temperature gives stereoselectively (E)-α-stannyl-α,β-unsaturated esters 1 in good yields. (E)-α-Stannyl-α,β-unsaturated esters 1 are difunctional group reagents that undergo Stille coupling reactions with alkenyl halides 2 in the presence of Pd(PPh3)4 and CuI co-catalyst to afford stereoselectively (1Z,3E)-2-ethoxycarbonyl-substituted 1,3-dienes 3 in good yields. 相似文献
12.
One novel triterpenoid ester, oleanol 28-aldehyde 3-O-β-palmitate (1), was isolated from the aerial part of Lobelia sessilifolia Lamb. along with seven known compounds, namely two triterpenoid esters (2, 3), one sterol (4), two coumarins (5, 6), and two triterpenes (7, 8). The structure of 1 was established on the basis of spectroscopic and chemical data. 相似文献
13.
贫电子环丙烷衍生物1以精制四氢呋喃为溶剂, 与2-巯基苯骈噻唑(2)封管加热反应, 得到产物3和4. 产物3经IR, MS, 1H NMR, 13C NMR和元素分析等数据确定其结构为: (R)-β-取代-(R)-γ-(2-巯基)苯骈噻唑基-γ-对位取代苯基丁酸或(S)-β-取代-(S)-γ-(2-巯基)苯骈噻唑基-γ-对位取代苯基丁酸(3); 产物4通过IR, MS, 1H NMR, 13C NMR, 2D-NOESY谱和元素分析等数据确定其结构为: 反式-β-取代-γ-对位取代苯基-3-丁烯酸(4). 对生成产物的机理也进行了推测. 相似文献
14.
Roccellatol, a new (2′R,3′S)-erythrityl-2,6-dihydroxy-4-methylbenzoate was isolated along with nine known compounds from the fruticose lichen, Roccella montagnei Bel. em. D.D. Awasthi. The structure of the new compound was elucidated by detailed spectroscopic analysis (1H, 13C, DEPT and HRMS). The present isolation of roccellatol (10) assumes significance as the esters of p-orcellinic acid are rare in lichens. Interestingly, among the known compounds, (+)-montagnetol (9) was now isolated in very large quantity (4.66%). 相似文献
15.
D. J. Byron A. S. Matharu S. N. R. Shirazi A. R. Tajbakhsh R. C. Wilson 《Liquid crystals》2013,40(3):645-652
Abstract Seventeen esters, derived from 4-n-alkoxy-3-fluorophenols and 4-(5-n-alkyl-2-thienyl)benzoic acids, have been prepared and their liquid crystal transition temperatures determined by thermal optical microscopy. On cooling the isotropic liquid, the SA-SC-SA sequence of phases reported for the octyloxy-octyl and octyloxy-nonyl esters has been observed for certain other homologues, principally members of the 4-(5-n-nonyl-2-thienyl)benzoates. For these compounds, the temperature range of occurrence of the intermediate SC phase decreases as the length of the alkoxy chain increases (for the hexyloxy-nonyl to dodecyloxy-nonyl esters) and the Sc phase is absent for the tetradecyloxy-nonyl homologue. 相似文献
16.
Tarik E. Ali Mohammed A. Assiri Hafez M. El-Shaaer Mohamed M. Hassan Ahmed M. Fouda Noha M. Hassanin 《合成通讯》2013,43(21):2983-2994
AbstractNovel chromenyl α-aminophosphonic acid 4 and dialkyl chromenyl phosphonate 6 have been obtained. In addition, some novel types of chromene fused with phosphorus heterocycles such as chromeno[4,3-c][1,2]azaphospholes 5 and 7, chromeno[2,3-d][1,3,2]diazaphosphinine 8 and 1,2-oxaphosphinino[3,4-c]pyridine 10 have been synthesized. The methodology depended on treatment of 2-imino-2H-chromene-3-carboxamide (1) with some phosphorus esters. The synthesized compounds were evaluated for antioxidant and cytotoxic activities. Among the synthesized compounds, compound 5 exhibited the most antioxidant activity with IC50 = 2.8?μg/mL in comparison with ascorbic acid as standard antioxidant. Also, compound 5 had significant cytotoxic effects against four cancer cell lines. Its IC50 values ranged between 4.96 and 7.44?μg/mL in comparison to doxorubicin (IC50 = 0.426–0.493?μg/mL). 相似文献
17.
Gerhard Buchbauer Waltraud Pernold Dorothea Rassl Brigitte Blach 《Monatshefte für Chemie / Chemical Monthly》1981,112(4):517-527
The synthesis of some new potentially, nitrogenefree spasmolytics is described. Formally the benzene nucleus in some mandelic acid esters, known by their mild spasmolytic activity, is substituted for the isocamphane bicyclus by a) SeO2 oxidation of 1-(3,3-Dimethyl-2-exo-norbornyl)-ethanone (5) to the corresponding ketoaldehyde6, b) oxidation of6 to the isocamphane analogous mandelic acid4 and c) esterification of derivatives of4 with isoamylalcohol and benzylalcohol. Attemps to dehydrate the methylester7 to camphenylideneacetic acid methylester (12) by various methods failed, probably because of the ring strain.
Teil der Diplomarbeit vonB. Blach, Universität Wien 1981. 相似文献
18.
Harry Raaijmakers Binne Zwanenburg Gordon J. F. Chittenden 《Journal of carbohydrate chemistry》2013,32(8):1117-1125
Abstract The reaction of methyl 4, 6-0-benzylidene-α-D-glucopyranoside 2, 3-cyclic carbonate (2) with 1-dodecanol in the presence of a catalytic amount of triethylamine to yield the 2-O-and the 3-O-alkoxycarbonyl esters 5 and 6 is described. Catalytic hydrogenation of 5 and 6 gave the deprotected mono-esters 3 and 4 which are of interest as potential non-ionic surfactants. The corresponding ethoxycarbonyl esters 7 and 8 were also prepared and their possible role as intermediates in the formation of 2 is discussed. 相似文献
19.
The preparation of furo[3,2-b]indoles via Dieckmann cyclization is described. The precursor diesters were obtained from 3-hydroxy-1H-indole-2-carboxylic acid esters and methyl or ethyl bromoacetate. Reactions of the furo[3,2-b]indole enolic esters prepared are discussed. 相似文献
20.
Lunli Xiang Lu Zhang Xuanqin Chen Xueshan Xia Rongtao Li 《Natural product research》2019,33(9):1349-1356
Investigation of the n-BuOH extract of the aerial parts of Elsholtzia bodinieri led to the isolation of two new ursane-type triterpenoid saponins, bodiniosides O (1) and P (2), along with five known saponins, rotungenoside (3), 3,28-O-bis-β-d-glucopyranosides of 19α-hydroxyarjunolic acid (4), oblonganosides I (5), rotungenic acid 28-O-α-L-rhamnopyranosyl-(1→2)-β-d-glucopyranoside (6), and bodinioside M (7) isolated from the species. The structures of compounds 1 and 2 were characterized by spectroscopic data as well as acid hydrolysis and GC analysis as 3-O-β-d-xylopyranosyl-23-acetoxy-urs-12(13)-en-28-oic acid 28-O-β-d-xylopyranosyl-(1→6)-[β-d-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)]-β-d-glucopyranoside and 3-O-β-d-xylopyranosyl-23-hydroxy-urs-12(13)-en-28-oic acid 28-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside. Compounds 1 and 2 exhibited potent anti-HCV activities in vitro with a selective index of 30.63 and 9.08, respectively. 相似文献