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1.
Three new withanolides have been isolated from hybrids obtained by crossing a chemotype of Withania somnifera received from South Africa and chemotype II originating in Israel. The compounds have been characterized as 4β,20α-dihydroxy-1-oxo-5β,6β-epoxy-20R,22R-witha-24-enolide, 20α-hydroxy-1,4-dioxo-5β,6β-epoxy-20R,22R-witha-2,24-dienolide, and 20α-hydroxy-1,4-dioxo-5β,6β-epoxy-20R,22R-witha-2-enolide. The major steroid of the plant is withanolide D, while the other known withanolides present are 4β,20α-dihydroxy-1-oxo-5β,6β-epoxy-20R,22R,24S,25R-witha-2-enolide and withaferin A. The structures assigned to the new compounds are based on spectral evidence, analysis of their fragmentation under electron impact, and on chemical correlation with known compounds. The formation of these withanolides in this new hybrid is discussed briefly.  相似文献   

2.
Hybrid plants of Withania somnifera from cross-pollinations of either chemotypes II or III (Israel) and Indian I (Delhi) have been examined. From both hybrids, 14β-hydroxywithanone (5,14β,17-trihydroxy-6,7-epoxy-1-oxo-22R-witha-2,24-dienolide) has been identified. This compound is the first example of a 14β-substitution among withanolides. From the second hybrid three additional new compounds were characterized: a 2,4,6-trien-1-one (14,2OF-dihydroxy-i-oxo-22R-witha-2,4,6,24-tetraenolide), a 14-hydroxywithanone (5,14,17-trihydroxy-6,7-epoxy-1-oxo-22R-witha-2,24-dienolide) and a 6β,7β-epoxywithanone (5,14,17-trihydroxy-6β,7β-epoxy-1-oxo-22R-witha-2,24-dienolide). An analysis of the inheritance characteristics of various substituents on the withanolide skeleton was based on the occurrence in per cent of each substituent in relation to the total withanolide content in the hybrid plants and their respective parents.  相似文献   

3.
The structure of a new chlorinated withanolide isolated from the hybrid plants of Withania somnifera, chemotypes III (Israel) by Indian I, is established as the chlorohydrin of withanolide D (6α-chloro-4β,5β,20αF-trihydroxy-l-oxo-22R-witha-2,24-dienolide). Two other known chlorinated withanolides had been isolated from different sources and additional data are provided, including the X-ray diffraction study of 4-deoxyphysalolactone (chlorohydrin of withanolide E). All available data are used for comparative analysis of the six known chlorinated withanolides. The origin of the chlorine atom in these compounds in the plants has been determined by carrying out a simple reaction of withanolide D with NaCl on silica gel.  相似文献   

4.
Recently Dhar et al. reported the isolation of two new steroidal lactones from the leaves of Datura quercifolia HBK and formulated them as 5α,12α,17α-trihydroxy-1-oxo-6α, 7α-epoxy-22 S-witha-2,24-dienolide and 5α,17α-dihydroxy-1, 12-dioxo-6α,7α-epoxy-22 S-witha-2,24-dienolide on the basis of UV, IR, NMR and MS studies. Further detailed chemical and spectral studies have led to revised structures, namely 5α, 12α-dihydroxy-1-oxo-6α,7α: 24α, 25α-diepoxy-20 S, 22 R-with-2-enolide and 5α-hydroxy-1, 12-dioxo-6α, 7α: 24α, 25α-diepoxy-20 S, 22 R-with-2-enolide, respectively, for the above two compounds.  相似文献   

5.
The structure of 1α,3β,20αF-trihydroxy-20R,22R-witha-5,24-dienolide, a new naturally occurring steroidal lactone of the withanolide g  相似文献   

6.
A new steroidal lactone of the withanolide group has been isolated from two Datura species and three hybrids and characterized as (20R,22R-5α,12α-dihydroxy-1-oxo-6α, 7α-epoxywitha-2,24-dienolide. The distribution of six withanolides throughout section Stramonium of the genus has been investigated.  相似文献   

7.
A novel withanolide, 5α,12β-dihydroxy-1-oxo-6α,7α-epoxy-(22R)-witha-2,24 dienolide was isolated from a benzene extract of fresh leaves of Datura quercifolia. The structure was established by chemical and spectroscopic methods.  相似文献   

8.
The structure of a new withanolide was elucidated as 3β,14α,2OαF,27-tetrahydroxy-1-oxo-20R,22R-witha-5,24-dienolide using chemical and spectroscopic methods. The structure was corroborated by comparative studies with known closely related withanolides. Sitosterol-β-d-glucoside was identified through chemical and spectroscopic means.  相似文献   

9.
The structure of a new naturally occurring steroidal lactone of the withanolide group isolated from Withania somnifera chemotype III has been elucidated as (20R,22R)-14α,2OαF-dihydroxy-1-oxowitha-2,5,16,24-tetraenolid. This compound is considered to be an intermediate in the biosynthesis of withanolide E, and is at the origin of the unusual α-oriented side-chain in this compound. The comparative composition of withanolides in different sub-chemotypes of III is provided.  相似文献   

10.
From Acnistus breviflorus the new 27-hydroxy-5β,6β-epoxy-1-oxo-(22R)-witha-24-enolide (2,3-dihydrojaborosalactone A) as well as seven known withanolides, withaferin A, 2,3-dihydrowithaferin A, 6α-chloro-5β-hydroxywithaferin A, 5,6-deoxywithaferin A, jaborosalactone A, jaborosalactone D and jaborosalactone E were isolated and characterized by means of spectroscopic (1H NMR, 13 C NMR and mass spectral) methods. Depending on the extraction solvent (methanol or ethanol), a known artifact (3β-methoxy-2,3-dihydrowithaferin A) and the new 5α-methoxy-4,5-dihydrojaborosalactone B and 5α-ethoxy-4,5-dihydrojaborosalactone B were also isolated and characterized.  相似文献   

11.
Two withanolides, 20beta-hydroxy-1-oxo-(22R)-witha-2,5,24-trienolide (1) and withacoagulin (2), along with a known withanolide, 17beta-hydroxy-14alpha, 20alpha-epoxy-1-oxo-(22R)-witha-3,5,24-trienolide (3) were isolated from Withania coagulans. Their structures were elucidated with the help of different spectroscopic techniques.  相似文献   

12.
《Phytochemistry》1987,26(6):1791-1795
The structure of a new withanolide type isolated from Trechonaetes laciniata, having a hemiacetal ring system and a 5-member ring lactone has been elucidated by X-ray analysis as (23R)-5β,6β-epoxy-12β,17β-dihydroxy-1-oxo-12,22-hemiacetal-ergosta-2,24-dien-23,26-olide (trechonolide A). A second compound (trechonolide B) having at C-12 a β-methoxy group, has also been isolated and assumed to be an artifact since, by heating trechonolide A in methanol with a trace of acid, the methoxy derivative was produced.  相似文献   

13.
《Phytochemistry》1987,26(9):2641-2643
A novel withanolide, daturilin, has been isolated from the alcohol soluble extract of the fresh leaves of D. metel and its structure established as 1-oxo-21,24S-epoxy- (20S,22S)-witha-2,5,25-trienolide through spectral studies including 2D NMR.  相似文献   

14.
Withanolide D, 7β-acetoxy-withanolide D and two new withanolide glycosides, named dunawithanines A and B, were isolated from Dunalia australis. From physical data and chemical transformations, the structures of the new compounds were determined as (20R,22R-O(3)-[2′,3′-di-O-(β-D-glucopyranosyl)-β-D-glucopyranosyl]-3β,20-dihydroxy-1α-acetoxy-witha-5,24-dienolide and the corresponding O(3)-[β-D-glucopyranosyl(1′ → x)-β-D- glucopyranosyl] compound, representing the first withanolide glycosides found in the plant kingdom.  相似文献   

15.
Strophasterols E (1) and F (2) were isolated from the fruiting bodies of Pleurotus eryngii, together with four new ergostane-type sterols (36). Single-crystal X-ray diffraction analysis performed on the tris-p-bromobenzoate derivatives of compounds 1 and 2 allowed these two compounds to be identified as the structurally rare (22S,23R)- and (22S,23S)-5α,6α-epoxy-3β,7β,23-trihydroxy-15(14 → 22)-abeo-ergost-8-en-14-one, respectively. The inhibitory effects on nitric oxide production of the six new steroids thus isolated from the fruiting bodies of P. eryngii were also evaluated.  相似文献   

16.
The stem of Cabralea canjerana (Vell.) Mart. yielded three new dammarane triterpenes 20S,24S-epoxy-7β,25-dihydroxy-3,4-secodammar-4(28)-en-3-oic acid, 20S,24S-epoxy-7β,15α,25-trihydroxy-3,4-secodammar-4(28)-en-3-oic acid and 20S,24R-epoxy-7β,22ξ,25-trihydroxy-3,4-secodammar-4(28)-en-3-oic acid, which were identified on the basis of spectroscopic methods. The known dammarane triterpenes ocotillone, eichlerianic acid, shoreic acid and the sterols sitosterol, campesterol, stigmasterol, sitostenone and stigmast-5-en-3-one were also isolated and identified. The branches yielded the above three known dammaranes and eichlerialactone. The dammaranes in C. canjerana display strong similarities with Trichilieae tribe, which contains several dammaranes. The data reported herein thus provide firm support for placing Cabralea within the subfamily Melioideae, Trichilieae tribe.  相似文献   

17.
From bulbs of Tristagma uniflorum the known sapogenins tigogenin, neotigogenin and (20S,22R,25S)-5α-spirostan-3β,25-diol, as well as the new (20S,22R,25R)-5α-spirostan-3β,25-diol, (20S,22S,25S)-5α-furostan-22,25-epoxy-3β,26-diol and (20S,22S,25R) -5α-furostan-22,25-epoxy-3β,26-diol, were isolated and characterized by spectroscopic (IR, 1H NMR, 13C NMR, MS) methods.  相似文献   

18.
Withanolide-type steroids, withametelin Q (1) and 12α-hydroxydaturametelin B (2) along with three known withanolides, were isolated from leaves of Datura metel L. (Solanaceae). The respective structures, characterized mainly by NMR spectroscopy, were identified as (20R,22R,24R)-21,24-epoxy-1α,3β-dihydroxywitha-5,25(27)-dienolide-3-O-β-d-glucopyranoside (1) and (20R,22R,24R)-12α,21,27-trihydroxy-1-oxowitha-2,5,24-trienolide-27-O-β-d-glucopyranoside (2). The cytotoxicity of isolated compounds was evaluated against human lung carcinoma cells (A549) and human colorectal adenocarcinoma cells (DLD-1), respectively. Compound 2 exhibited cytotoxicity against A549 and DLD-1 cell lines, with IC50 values of 7 and 2.0 μM, respectively. However, for compounds 6 and 7, cytotoxicities were higher against DLD-1 cells with IC50 values of 0.6 and 0.7 μM. Both compounds blocked the cell cycle in the S-phase and induced apoptosis.  相似文献   

19.
Seven new withanolides (1-7), along with three known ones (8-10), were isolated from the leaves of Withania aristata. Their structures were elucidated on the basis of spectroscopic analysis, including 2D NMR experiments and spectrometric techniques, and the absolute configuration of 1 and 2 was established by CD analysis. In the search for new cytotoxic compounds from Withania species, the isolated compounds 1-9, along with two derivatives, were assayed for their cytotoxicity against HeLa, MCF-7 and A-549 human tumor cell lines. Derivative (4S,20R,22R)-27-acetoxy-4-p-bromobenzoyloxy-1-oxo-witha-2,5,16,24-tetraenolide (13) showed cytotoxicity against all the cell lines assayed with IC50 values ranging from 2.8 to 3.6 μM, and (4S,20R,22R)-4,27-diacetoxy-4-hydroxy-1-oxo-witha-2,5,16,24-tetraenolide (12) exhibited an IC50 value of 5.4 μM on the MCF-7 cell line.  相似文献   

20.
The chemical examination of Acnistus breviflorus afforded nine withanolides, four of which are new and were established as 2,3,24,25-tetrahydro-27-desoxywithaferin A (4β-hydroxy-5β,6β-epoxy-1-oxo-22R-withanolide), 2,3-dihydro-27-desoxywithaferin A (4β-hydroxy-5β,6β-epoxy-22R-witha-24-enolide), 5,6-desoxywithaferin A (4β,27-dihydroxy-1-oxo-22R-witha-2,5,24-trienolide) and 2,3-dihydro-5,6-desoxywithaferin A (4β,27-dihydroxy-1-oxo-22R-witha-5,24-dienolide). The five known compounds were: withaferin A; 2,3-dihydrowithaferin A; 24,25-dihydro-27-desoxywithaferin A and withaferin A-6,5β-chlorohydrin.  相似文献   

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