共查询到20条相似文献,搜索用时 78 毫秒
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本文报导以胆甾醇为原料经五步反应合成了4α—甲基—5α—胆甾烷与4β—甲基—5α—胆甾烷的混合物。其关键反应是利用胆甾—4—烯—3,6—二酮和重氮甲烷反应而引入4—甲基。 相似文献
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西松烷型二萜天然产物全合成最新进展 总被引:3,自引:0,他引:3
西松烷型二萜类化合物是近年来相继发现的一大类结构新颖,特殊且具有重要生物活性的天然产物。本文将扼要地论述近几年此类化合物的全合成最新研究进展,其中包括我国近年来的研究成果。 相似文献
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Kang LP Liu ZJ Zhang L Tan DW Zhao Y Zhao Y Chen HB Ma BP 《Magnetic resonance in chemistry : MRC》2007,45(9):725-733
An analysis of the polar extracts from Allium ascalonicum L. led to the isolation of two new furostanol saponins (compound 1 and 2) and two known furostanol saponins (compound 3 and 4). On the basis of 1D and 2D NMR (including (1)H, (13)C NMR, (1)H--(1)H COSY, HSQC, TOCSY, HMBC, and NOESY), FAB-MS spectrometry, and chemical methods, their structures were elucidated as (25R)-26-O-beta-D-glucopyranosyl-22-hydroxy-5alpha-furost-2-one-3beta, 5, 6beta, 26-tetraol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside (ascalonicoside C, 1), (25R)-26-O-beta-D-glucopyranosyl-22-methoxy-5alpha-furost-2-one-3beta, 5, 6beta, 26-tetraol- 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside (ascalonicoside D, 2), (25R)-26-O-beta-D-glucopyranosyl-22-hydroxy-5-ene-furostan-3beta, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->4)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-glucopyranoside (dichotomin, 3), and (25R)-26-O-beta-D-glucopyranosyl-22-hydroxy-5-ene-furostan-3beta, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-arabinofuranosyl-(1-->4)]-beta-D- glucopyranoside (parisaponin I, 4). 相似文献
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Zou P Fu J Yu HS Zhang J Kang LP Ma BP Yan XZ 《Magnetic resonance in chemistry : MRC》2006,44(12):1090-1095
The detailed NMR studies and full assignments of the 1H and 13C spectral data for two new furostanol saponins isolated from Agave sisalana leaves are described. Their structures were established using a combination of 1D and 2D NMR techniques including 1H, 13C, 1H-1H COSY, TOCSY, HSQC, HMBC and HSQC-TOCSY, and also FAB-MS spectrometry and chemical methods. The structures were established as (25S)-26-(beta-D-glucopyranosyl)-22 xi-hydroxyfurost-12-one-3beta-yl-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galacto- pyranoside (1) and (25S)-26-(beta-D-glucopyranosyl)-22xi-hydroxyfurost-5-en-12-one-3beta-yl-O-alpha-L-rhamno- pyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl- (1-->4)-beta-D-galactopyranoside (2). 相似文献
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Three new steroidal saponins including two spirostanol glycosides (1–2) and one furostanol glycoside 1-sulphate (3) were isolated from the dried roots and rhizomes of Helleborus thibetanus. Structures of the compounds were determined on the basis of extensive use of 1-D and 2-D NMR experiments, together with HR–ESI–MS and IR measurements, as well as the results of acid hydrolysis. Compounds 1–2 represented steroidal saponins with an unusual substitution pattern, which possessed a double bond at C-25 and were glycosylated at 1-OH. 相似文献
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Kun Zou Jun‐zhi Wang Zhi‐yong Guo Ming Du Jun Wu Yuan Zhou Fei‐jun Dan Chuang Liu 《Magnetic resonance in chemistry : MRC》2009,47(1):87-91
Four new furostanol saponins (1–4), two pairs of diastereoisomers, were isolated from methanolic extracts of Tupistra chinensis rhizomes and their structures were assigned from 1H and 13C NMR spectra, DEPT, and by 2D COSY, NOESY, HMQC, and HMBC experiments. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Agrawal PK 《Magnetic resonance in chemistry : MRC》2004,42(11):990-993
An approach based on the difference (Delta(ab) = delta(a) - delta(b)) between the 1H NMR chemical shifts (delta(a), delta(b)) of the geminal protons of glycosyloxy methylene (H2-26) (Delta(ab) = <0.48 for 25R; Delta(ab) = >0.57 for 25S) is proposed for ascertaining 25R/25S orientation of the 27-methyl group of furostane-type steroidal saponins. These studies suggested the 25R-orientation of the 27-Me group for the furostanol glycosides isolated by Wu et al. from Tribulus terrestris. 相似文献
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Zhiyong Guo Kun Zou Junzhi Wang Chuang Liu Zichun Tang Chunyan Yang 《Magnetic resonance in chemistry : MRC》2009,47(7):613-616
Three new furostanol saponins (1–3) were isolated from the roots of Tupistra chinensis (T. chinensis). And their structures were elucidated on the basis of NMR and mass spectrometry (MS) spectral analysis. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Two new furostanol saponins from the seeds of Allium cepa L. 总被引:1,自引:0,他引:1
Ling Yuan Teng Fei Ji Ai Guo Wang Jian Bo Yang Ya Lun Su~* Institute of Materia Medica Chinese Academy of Medical Sciences Key Laboratory of Bioactive Substances Resources Utilization of Chinese Herbal Medicine Peking Union Medical College Ministry of Education Xiannongtan Street Beijing China 《中国化学快报》2008,19(4):461-464
Phytochemical analysis of the n-BuOH extract from the seeds ofAllium cepa L.led to isolation of four furostanol saponins,two of which were new compounds,named ceparoside A(la)and ceparoside B(2a).The chemical structures of the new compounds were elucidated through a combination of NMR,MS spectral data and chemical analysis. 相似文献
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Bernadete Pereira da Silva Patricia Oliveira Campos Jose Paz Parente 《Chemistry of Natural Compounds》2006,42(3):316-321
A new bisdesmosidic furostanol saponin, along with a known spirostanol saponin, furcreastatin, were isolated from Furcraea gigantea Vent. (Agavaceae). The structure of the new saponin was elucidated as 3-[(O-6-deoxy-α-L-mannopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1å 3)-O-[O-β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→2)-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranosyl)oxy]-(3β, 5α, 25R)-26-(β-D-glucopyranosyloxy)-22-hydroxyfurost-12-one. The structural identification was performed using a combination of spectroscopic techniques and chemical conversions. Furcreastatin showed a powerful haemolytic effect in the in vitro assay, but the new bisdesmosidic furostanol saponin demonstrated only a significant inhibition of the capillary permeability activity. 相似文献
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Chao Zhang Shuyue Wang Fei Guo Ting Ma Longfei Zhang Linlin Sun Yingzi Wang Xuelan Zhang 《Biomedical chromatography : BMC》2020,34(4):e4794
Just as natural saponins transform into aglycones, secondary glycosides and their derivatives using biotransformation technology, steroidal saponins may also undergo similar transformation after stir-frying. The purpose of this study was to elucidate the variations and the reasons for these variations in the contents of steroidal saponins in Fructus Tribuli (FT) during a stir-frying treatment. Stir-fried FT was processed in different time–temperature conditions. An UHPLC–MS/MS method was established and fully validated for quantitative analysis. In addition, the simulation processing products of tribuluside A, terrestroside B, terrestrosin K, terrestrosin D and 25R-tribulosin were determined by qualitative analysis using UHPLC–Q-TOF–MS. The established UHPLC–MS/MS method provides a rapid, flexible, and reliable method for the quality assessment of FT. The present study revealed that furostanol saponins with a C22-OH group could transform into corresponding furostanol saponins with a C-20–C-22 double bond (FSDB) via dehydroxylation. Additionally, FSDB could be successively converted into its secondary glycosides via a deglycosylation reaction. The transformation of spirostanol saponins into corresponding aglycones via deglycosylation led to a decrease in spirostanol saponins and an increase in aglycones. The results of this research provided scientific evidence of variation and structural transformation among steroidal saponins. These findings might be helpful for elucidating the processing mechanism of FT. 相似文献
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Tao Lin Hui‐Lian Huang Rong‐Hua Liu Ji‐Cheng Shu Gang Ren Feng Shao Li‐sha Liu 《Magnetic resonance in chemistry : MRC》2012,50(12):813-817
Six steroidal saponins and two pregnane glycosides were isolated from the BuOH subfraction of 70% EtOH extract of Smilax microphylla C.H.Wright, among them two were new compounds (1 and 7). Pregnane glycosides were firstly isolated from the genus Smilax (Smilacaceae). Structures of the new compounds were determined on the basis of HR‐ESI‐MS, 1D and 2D NMR spectroscopic analysis. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献