全文获取类型
收费全文 | 164篇 |
免费 | 4篇 |
国内免费 | 7篇 |
出版年
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 2篇 |
2017年 | 10篇 |
2016年 | 5篇 |
2015年 | 12篇 |
2014年 | 9篇 |
2013年 | 8篇 |
2012年 | 2篇 |
2011年 | 8篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 9篇 |
2005年 | 6篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2002年 | 11篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有175条查询结果,搜索用时 15 毫秒
91.
柴胡皂甙p的结构鉴定 总被引:4,自引:0,他引:4
从小叶黑柴胡 Bupleurum smithii Wolff var.parvifolium 的根中分离得到 5个化合物 ~ .经化学和波谱方法鉴定 ,化合物 为 3β,1 6β,2 3,2 8-四羟基齐墩果 - 1 1 ,1 3 1 8 -二烯 - 3- O- β- D-吡喃葡萄糖基 1→ 6 - [β- D-吡喃葡萄糖基 1→ 2 ]- β- D-吡喃葡萄糖甙 ,为新化合物 ,命名为柴胡皂甙 p saikosaponin p .化合物 ~ 分别为已知化合物柴胡皂甙元 D 、柴胡皂甙 g 、柴胡次皂甙 H 和柴胡皂甙 b2 .它们均首次从小叶黑柴胡中获得 相似文献
92.
藏玄参中的抑精三萜皂甙 总被引:1,自引:0,他引:1
从藏药植物藏玄参(OreosolenwattiiHook.f.)的全草中分离到4个三萜皂甙,密蒙花甙(mimengoside)A和B及醉鱼草甙(buddlejasaponin)I和Ia,另外还得到阿克甙(acteoside)和6-羟基木犀草素-7-O-葡萄糖甙(6-hydroxyluteolin-7-O-glucoside)。体外抑精实验表明,4个三萜皂甙均有较强的抑精活性,其中密蒙花甙A和醉鱼草 相似文献
93.
梁光义 《Acta Botanica Sinica》1988,(4)
从刺梨中分离出两个五环三萜酯甙,通过光谱分析和衍生物的制备确定其为刺梨甙和野蔷薇甙,这两个化合物互为差向异构体。 相似文献
94.
Constituents from the Roots of Actinidia chinensis and Their Cytochrome P450 Enzyme Inhibitory Activities 下载免费PDF全文
Yi‐Xin Xu Zhao‐Bao Xiang Yong‐Sheng Jin Wen Xu Lian‐Na Sun Wan‐Sheng Chen Hai‐Sheng Chen 《化学与生物多样性》2016,13(11):1454-1459
A newly discovered triterpenoid, (2α,3β)‐2,3,23‐trihydroxyurs‐13(18)‐en‐28‐oic acid ( 1 ), along with twelve known compounds ( 2 – 13 ), were isolated from the roots of Actinidia chinensis Planch (Actinidiaceae). Their chemical structures were determined by 1D‐ and 2D‐NMR spectra and mass spectrometry (MS). The crude extracts and six main constituents ( 8 – 13 ) were tested for cytochrome P450 (CYPs) enzyme inhibitory activity. The results showed that, except for compound 8 , compounds 9 – 13 had different inhibitory effects on the cytochrome P450 (CYPs) enzyme, and compound 9 significantly inhibited the catalytic activities of CYP3A4 to < 10% of its control activities. 相似文献
95.
A phytochemical analysis of Dianthus erinaceus Boiss. var. erinaceus (Caryophyllaceae) has led to the isolation of two novel triterpenoid saponins, containing an oleane type skeleton, named dianosides K and L (1, 2), along with six known triterpenoid saponins (3–8). On the basis of chemical and spectrometric data, the structures of the new compounds were elucidated as 3-O-[β-d-glucopyranosyl (1 → 3)]–[β-d-glucopyranosyl (1 → 6)]-β-d-glucopyranosyl-olean-12-ene-23α,28-β–dioic acid 28-O-β-d-glucopyranosyl ester (1) and 3-O-[β-d-glucopyranosyl (1 → 3)]–[β-d-glucopyranosyl(1 → 6)]-β-d-glucopyranosyl-olean-12-ene-23α,28-β-dioic acid 28-O-α-l-mannopyranosyl (1 → 6)-β-d-glucopyranosyl ester (2). All isolated natural compounds were structurally characterized by 1D- (1H, 13C, DEPT); 2D- (COSY, HMQC, HMBC) NMR and HR-ESI/MS methods. The antimicrobial activity of compounds 1 and 2 were tested against four Gram-negative, three Gram-positive bacteria and the yeast Candida albicans by the MIC method. 相似文献
96.
Thirty-four reported compounds were obtained from Anemone vitifolia Buch.-Ham., and were identified as triterpenoid saponins (1–28), flavonoid glycosides (29–32) and steroidal saponins (33–34). The structure of these compounds was determined by physicochemical constants and spectral analyses (NMR, MS, IR). Twelve compounds (7, 8, 10, 14, 20, 21, 23, 26–28, 30 and 32) were firstly identified in genus Anemone. Compounds 2, 4 and 14 can be considered as characteristic components of A. vitifolia. Finally, the chemotaxonomic significance of these compounds is discussed. 相似文献
97.
Phytochemical investigation of a Chinese fern Lepidogrammitis drymoglossoides led to the isolation of five compounds, including one triterpenoid, two lignans and two glycosides. Their structures were determined to be filic-3-ene-28-oic acid (1), (−)-syringaresinol-4-O-beta-d-glucopyranoside (2), lyoniresinol (3), 4-O-beta-d-glucopyranosyl caffeic acid (4) and n-butyl-O-beta-d-fructopyranoside (5) on the basis of mass and NMR spectra and chemical and physical properties. Filic-3-ene-28-oic acid (1) is a new triterpenoid, while compounds 2–5 were isolated from the genus Lepidogrammitis for the first time. Chemotaxonomic significance of this investigation is summarized. 相似文献
98.
99.
Three new oleanane-type saponins, leptocarposide B-D (1–3), were isolated from the whole plant of Ludwigia leptocarpa (Nutt.) Hara, together with ten known compounds 4–13.The structures of these compounds were determined by interpretation of their spectral data, mainly HR-TOFESIMS, 1D-NMR (1H, 13C) and 2D-NMR (1H–1H COSY, HSQC, HMBC, and NOESY), and by comparison with the literature data. The structures of the new compounds were established as 28-O-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-[α-l-arabinopyranosyl-(1 → 3)]-4-O-(3′-hydroxybutanoyloxy-3-hydroxybutanoyloxy)-β-d-fucopyranosyl zanhic acid (1); 3-O-β-d-glucopyranosyl-28-O-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-4-O-(3′-hydroxybutanoyloxy-3-hydroxybutanoyloxy)-β-d-fucopyranosyl medicagenic acid (2); 3-O-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl-28-O-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-[α-l- arabinopyranosyl-(1 → 3)]-4-O-(3′-hydroxybutanoyloxy-3-hydroxybutanoyloxy)-β-d-fucopyranosyl zanhic acid (3). 相似文献
100.
Phytochemical investigation of the stem bark of Ficus natalensis afforded eleven compounds including one ceramide (1), two anthraquinones (2, 3), four triterpenes (4–7), two polyols (8, 9) and two steroids (10, 11). The structures of the compounds were determined by spectroscopic analyses including IR, UV, MS, 1D- and 2D- NMR (1H, 13C, 1H–1H COSY, HMQC, HMBC and NOESY), as well as by comparison with literature data. The antibacterial activity and the cytotoxicity of the extract, fractions and some isolated compounds (3, 5, 8 and 9) were evaluated. Some fractions and sub-fractions from various column chromatography displayed moderate antibacterial activity with diameter zone of inhibition (DZI) ranging from 7 to 10 mm. None of the compounds tested had activity. In the present study, all the compounds are isolated for the first time from the species F. natalensis. Compounds 2, 4–7, 10 and 11 were previously reported from the genus Ficus. The chemophenetic significance of the isolated compounds is discussed. 相似文献