排序方式: 共有21条查询结果,搜索用时 15 毫秒
11.
John L. Ingham 《Biochemical Systematics and Ecology》1978,6(3):217-223
The fungus-inoculated leaflets of 55 Trifolium species have been examined for the presence of isoflavonoid and non-flavonoid phytoalexins. Isoflavonoid derivatives belonging to the pterocarpan (medicarpin, maackiain and 4-methoxymaackiain) and isoflavan (vestitol, isovestitol, sativan, isosativan and arvensan) classes were isolated from 50 species whilst T. campestre and T. dubium accumulated the trihydroxy stilbene, transresveratrol. Three other species (T. badium, T. scutatum and T. spadiceum) apparently did not produce phytoalexins in response to fungal inoculation. The distribution and biosynthetic relationship of Trifolium phytoalexins is discussed and the genus compared with others belonging to the Trifolieae and related tribes. 相似文献
12.
Otto R. Gottlieb Alaíde Braga de Oliveira Terezinha M. Machado Gonçalves Geovane G. de Oliveira Sebastião A. Pereira 《Phytochemistry》1975,14(11):2495-2499
(3R)-Claussequinone (7-hydroxy-4′-methoxyisoflavanquinone is the principal constituent of Cyclolobium clausseni Benth. and C. vecchii A. 相似文献
13.
Eight flavonoids have been isolated from the root of Abrus precatorius L. Among them, six isoflavanquinones, designated (3R)-abruquinone A, B, D and E, (3S)-abruquinone F and G, are characterized by chemical and spectral means including 1H-1H COSY, 1H-13C COSY and CD methods. 相似文献
14.
Oliver R.W. Sutherland Graeme B. Russell David R. Biggs Geoffrey A. Lane 《Biochemical Systematics and Ecology》1980,8(1):73-75
When incorporated into an agar-cellulose medium containing feeding stimulants, phytoalexin isoflavonoids from several legumes show feeding deterrent activity against larvae of the insect Costelytra zealandica and Heteronychus arator. The levels at which these compounds deter feeding are of the same order of magnitude as those at which they reduce fungal growth. The most active compound tested was phaseollin. These results suggest that phytoalexin isoflavonoids show a dual acitvity against insects and fungi. 相似文献
15.
A new phytoalexin isolated from the fungus-inoculated leaflets of Astragalus cicer has been identified as 7-hydroxy-2′-methoxy-4′,5′-methylenedioxyisoflavan (astraciceran). The synthesis of astraciceran and its 3′,4′-methylenedioxy analogue is described. 相似文献
16.
A new pterocarpan, (6aR, llaR)-3, 9-dimethoxy-l0-hydroxypterocarpan with four known compounds, (6aR,11aR)-3,9,10-tri-methoxypterocarpan,9,l0-di-methoxypterocarpan-3-O-β-D-glucopyranoside, (3R)-2'-hydroxy-7, 3', 4'-trimethoxy-isoflavan, 2'-hydroxy-3', 4'- dimethoxyisoflavan-7-O-β-D-glucopyranoside, were isolated from ethanolic extract of the root of Astragalus membranaceus (Fisch.) Bunge. Their structures were elucidated by means of spectral analysis and chemical conversions. 相似文献
17.
A new isoflavonoid phytoalexin isolated from the fungus-inoculated leaflets of Lotus hispidus (hairy birdsfoot trefoil) has been identified as 5,4′-dimethoxy-7,2′-dihydroxyisoflavan (5-methoxyvestitol). Three known isoflavans (demethylvestitol, vestitol and sativan) are also produced by L. hispidus. The synthesis of 5-, 6- and 8-methoxyvestitol is described. Preparation of the pterocarpan analogues of 6- and 8-methoxyvestitol has allowed the structures of two additional legume phytoalexins to be unequivocally confirmed. 相似文献
18.
Kazu Kurosawa W.David Ollis Brian T. Redman Ian O. Sutherland Otto R. Gottlieb 《Phytochemistry》1978,17(8):1413-1415
The wood of Machaerium vestitum contains the previously described O-acetyloleanolic aldehyde, formononetin, (+)-medicarpin, and (?)-mucronulatol, besides (+)-vestitol [(3S)-7,2′-dihydroxy-4-methoxyisoflavan] and (+)-vesticarpan [(6aS,11aS)-3,10-dihydroxy-9-methoxypterocarpan]. The constitutions of vestitol and vesticarpan were deduced by spectra and confirmed by syntheses. 相似文献
19.
John L. Ingham 《Phytochemistry》1977,16(8):1279-1282
Two previously unreported phytoalexins, 7,4′dihydroxy-2′-methoxy- and 7,2′,4′-trihydroxyisoflavan, have been isolated from the fungus-inoculated leaves of Anthyllis vulneraria and 5 Tetragonolobus species. Examination of Lotus corniculatus revealed the co-occurrence of the latter with the known isoflavans, vestitol and sativan. Only 7,2′4′-trihydroxyisoflavan and vestitol were produced by the closely related L. uliginosus. 相似文献
20.
John L. Ingham 《Biochemical Systematics and Ecology》1979,7(1):29-34
Detached leaves of 25 annual and perennial Medicago species have been inoculated with the fungus, Helminthosporium carbonum, and examined for subsequent production of isoflavonoid phytoalexins. Hydroxylated pterocarpan (medicarpin) and isoflavan (vestitol, sativan and isosativan) phytoalexins were obtained from most of the species investigated. Although large quantities of two flavonoid derivatives, isoliquiritigenin and liquiritigenin, were isolated from leaves of M. lupulina, this species was apparently unable to produce isoflavonoid compounds. Traces of 7-hydroxy-2′,4′-dimethoxyisoflavanone (a substance not previously recorded in the tribe Trifolieae) were obtained (together with medicarpin, vestitol and sativan) from M. sativa cv Du Puits. Some taxonomic aspects of phytoalexin induction are discussed with reference to the generic location of certain controversial Medicago species including M. (Trigonella) radiata. 相似文献