排序方式: 共有21条查询结果,搜索用时 0 毫秒
1.
Bark and wood of the creeper Dalbergia variabilis contain the previously described friedelin, O-acetyl-oleanolic acid, formononetin, 8-O-methylretusin, (+)-vestitol, (±)-mucronulatol, (+)- and (±)-medicarpin, besides (+)-variabilin [(6aR,11aR)-6a-hydroxy-3,9-dimethoxypterocarpan]. This structure was confirmed by the conversion of (+)-variabilin into di-O-methylcoumestrol. 相似文献
2.
Kazu Kurosawa W.David Ollis Brian T. Redman Ian O. Sutherland Herbert M. Alves Otto R. Gottlieb 《Phytochemistry》1978,17(8):1423-1426
The absolute configurations of isoflavans and isoflavanquinones isolated from Cyclolobium, Dalbergia and Machaerium species were established by comparison of their ORD curves with that of (3S)-5,7,3′,4′-tetra-methoxyisoflavan and (3S)-7,4′-dimethoxyisoflavan-2′,5′-quinone, respectively. The assignments were checked by the ozonolysis of the isoflavan (?)-duartin to (R)-paraconic acid and the oxidation of isoflavans to isoflavanquinones. The PMR spectra of the dihydropyran ring of the isoflavans are discussed in terms of the preferred conformation of this ring. 相似文献
3.
4.
Kazu Kurosawa W.David Ollis Ian O. Sutherland Otto R. Gottlieb Alaide B. de Oliveira 《Phytochemistry》1978,17(8):1405-1411
Additionally to the cinnamylphenols described in a previous paper, wood samples of Machaerium mucronulatum and M. villosum contain isoflavones, besides (?)-duartin, (?)- and (±)-mucronulatol [(3S)- and rac-7,3′-dihydroxy-2′,4′-dimethoxyisoflavan], (?)-mucroquinone [(3S)-2-methoxy-5-(7-hydroxy-8-methoxychroman-3-yl)-1,4-benzoquinone] and (+)-mucronucarpan [(6aS,11aS)-2,10-dihydroxy-3,9-dimethoxypterocarpan]. The constitutions of mucronulatol, mucroquinone and mucronucarpan were deduced by spectra and degradations, and confirmed by syntheses. 相似文献
5.
6.
John L. Ingham 《Biochemical Systematics and Ecology》1981,9(4):275-281
Using the drop-diffusate technique, a number of isoflavonoid phytoalexins have been obtained from the excised, fungus-inoculated leaflets of 41 species belonging to the legume genus Trigonella. Leaf diffusates variously contained pterocarpan (medicarpin and maackiain) and isoflavan (vestitol and sativan) derivatives previously associated with genera closely allied to Trigonella. In diffusates from T. calliceras, medicarpin was accompanied by a phytoalexin (designated TC-1) provisionally identified as a new hydroxylated pterocarpan. Most of the Trigonella species were also examined for their ability to release coumarin upon tissue maceration. The combined phytoalexin/coumarin data suggest that three major intrageneric chemical divisions occur in Trigonella; two of these apparently link the genus to Medicado/Factorovskya and Melilotus respectively, whilst the third provides some evidence for a connection with Trifolium. The taxonomic aspects of these findings are discussed in the light of earlier morphological studies which provided evidence for a distinct floral dichotomy amongst Trigonella species. 相似文献
7.
A phytoalexin isolated from the fungus-inoculated leaflets of Lotus angustissimus and L. edulis has been characterised as 5,7-dimethoxy-2′,4′-dihydroxyisoflavan (lotisoflavan). The total synthesis of lotisoflavan is described. 相似文献
8.
Two phytoalexins, (-)-sativan, previously named sativin, [(-)-7-hydroxy-2′,4′-dimethoxyisoflavan], and (-)-vestitol, [(-)-7,2′-dihydroxy-4′-methoxyisoflavan], were induced by a spore suspension of Helminthosporium turcicum Pass. to accumulate in leaves of birdsfoot trefoil (Lotus corniculatus L.). 相似文献
9.
W.David Ollis Ian O. Sutherland Herbert M. Alves Otto R. Gottlieb 《Phytochemistry》1978,17(8):1401-1403
The heartwood of Machaerium opacum contains 2,3-dimethoxyphenol, the stilbenes pinosylvin monomethyl ether and dimethyl ether, and the isoflavans (?)-duartin and (?)-mucronulatol. The structure of (3S)-7,3′-dihydroxy-8,2′,4′-trimethoxyisoflavan was deduced for duartin and the constitution confirmed by synthesis of the racemate. 相似文献
10.
膜荚黄芪中的紫檀烷和异黄烷化合物 总被引:10,自引:0,他引:10
前文[1]报道了从膜荚芪(Astragalus membranaceus(Fish.)Bunge)根的乙醇提取物中分离得到的2 相似文献