Isoflavones from Xanthocercis zambesiaca

In addition to the previously described 7-hydroxy-8,4′-dimethoxy- and 7,3′-dihydroxy-8,4′-dimethoxy-isoflavone the heartwood of Xanthocercis zambesiaca has been shown to contain 7-hydroxy-8,3′,4′-trimethoxy-,3′,4′-dimethoxy-6,7-methylenedioxy- and 8,3′,4′-trimethoxy-6,7-methylenedioxy-isoflavone. A technique of determining isoflavone hydroxylation patterns by deuterium labelling is described.     

Two isoflavones from Piscidia erythrina

Two new prenylated isoflavones were isolated from the root bark of Piscidia erythrina. The first compound was identified as 2′-deoxypiscerythrone. The second compound, the most abundant component of the extract, was identified as 3′-6′-di-Δ²-isopentenyl-5,7,2′,4′-tetrahydroxy-5′-methoxyisoflavone.     

Isoflavones from Dipteryx odorata

Five isoflavones have been isolated from the heartwood of Dipteryx odorata: retusin, retusin 8-methyl ether, 3′-hydroxyretusin 8-methyl ether, odoratin (7,3′-dihydroxy-6,4′-dimethoxyisoflavone) and dipteryxin (7,8-dihydroxy-6,4′-dimethoxyisoflavone).     

New prenylated isoflavones from Millettia pachycarpa

Isolation of four new isoflavones from a new collection of Millettia pachycarpa is reported. Proof of the structure of lupinifolol, previously isolated from M. pachycarpa, by synthesis of dehydrolupinifolol is described.     

Isoflavones of two Iris species

Analysis of the methanol extracts of the rhizomes of Iris milesii resulted in the isolation of a new isoflavone, 5,6,7,4′-tetrahydroxy-3′-methoxyisoflavone and that of Iris kumaonensis, iriskumaonin methyl ether, iriskumaonin, irisflorentin, junipegenin-A, irigenin and iridin.     

Major isoflavonoids of the jamaican dogwood Piscidia erythrina

Reverse-phase HPLC analysis of the bark extracts of Jamaican dogwood Piscidia erythrina shows three main components. Two have been isolated and their structures have been interpreted through their spectroscopic characteristics as a known monoprenylated (piscidone) and a new diprenylated isoflavone.     

Two isoprenylated isoflavone phytoalexins from Cajanus cajan

Four phytoalexins were isolated from sliced seeds of pigeonpea which had been incubated with its native microflora. Two were identified as the known pigeonpea phytoalexins, cajanin and cajanol, and the other two were characterized as new isoprenylated isoflavones.     

Isoflavones and stilbenes from Juniperus macropoda

An ethanolic extract of Juniperus macropoda, after chromatography, yielded three isoflavones, viz.irigenin, iridin and a new compound. In addition two stilbenes, resveratrol and piceid (resveratrol-3-O-β-D-glucoside), were isolated and characterized.     

Isoflavones of Iris spuria

A new isoflavone, 5,7-dihydroxy-6,2′-dimethoxyisoflavone, together with iristectorigenin A and iristectorin A were isolated and characterized from the methanol extract of Iris spuria.     

大豆异黄酮抗辐射损伤的作用

大豆异黄酮是大豆中的一类多酚化合物。近年来一些体外细胞培养及动物实验表明,大豆异黄酮通过抗氧化、抑制细胞凋亡、调节细胞基因表达等作用机制,对辐射损伤有一定的防护作用。     

汽爆葛根直接固态发酵乙醇联产葛根黄酮

针对葛根原料富含纤维和黄酮等特点, 选用低压汽爆处理代替糊化直接固态同步糖化发酵乙醇, 而后提取发酵剩余物的葛根黄酮。实验结果表明鲜葛根在0.8 MPa压力下维持3.5 min汽爆处理后, 直接加入糖化酶(65 u/g)、纤维素酶(1.5 u/g), 0.1%(NH4)2SO4、0.1%KH2PO4和活化后的酵母, 35~37oC下, 固态同步糖化发酵60 h, 100 g干葛根可生产的乙醇与葛根黄酮分别为27.47 g、4.43 g, 淀粉利用率达到95%。该方法实现了葛根分层多级转化清洁利用, 为非粮食类淀粉资源发酵乙醇提供了一条新途径。     

汽爆葛根直接固态发酵乙醇联产葛根黄酮

针对葛根原料富含纤维和黄酮等特点, 选用低压汽爆处理代替糊化直接固态同步糖化发酵乙醇, 而后提取发酵剩余物的葛根黄酮。实验结果表明鲜葛根在0.8 MPa压力下维持3.5 min汽爆处理后, 直接加入糖化酶(65 u/g)、纤维素酶(1.5 u/g), 0.1%(NH4)2SO4、0.1%KH2PO4和活化后的酵母, 35~37oC下, 固态同步糖化发酵60 h, 100 g干葛根可生产的乙醇与葛根黄酮分别为27.47 g、4.43 g, 淀粉利用率达到95%。该方法实现了葛根分层多级转化清洁利用, 为非粮食类淀粉资源发酵乙醇提供了一条新途径。     

A new isoflavone phytoalexin from fungus-inoculated stems of Glycine wightii

6-Isopentenylgenistein 1 (wighteone) has been isolated as a phytoalexin from the fungus-inoculated or CuCl₂-treated stems of Glycine wightii. Plants treated with aqueous CuCl₂, but not those inoculated with the fungus, also accumulated genistein (2) and its 2′-hydroxy derivative (3).     

A chalcone and an isoflavone from Millettia pachycarpa seeds

Chemical examination of the seeds of Millettia pachycarpa has yielded a new prenylated isoflavone and a new prenylated chalcone in addition to the previously reported isoflavones 5-hydroxy-4′-methoxy-6″,6″-dimethylpyrano (2″,3″:7,8)isoflavone, 5,7,4′-trihydroxy-6,8-diprenylisoflavone, 5,7,3′,4′-tetrahydroxy-6,8-diprenyl-isoflavone and pomiferin.     

Flavonoids from Millettia pulchra

Chemical examination of Millettia pulchra yielded (?)-maackiain, (?)-pterocarpin, (?)-sophoranone and the new compounds (6S, 6aS, 11aR)-6α-methoxypterocarpin, (6S, 6aS,11aR)-6α-methoxyhomopterocarpin, (2S)5,7,4′-trihydroxy-8,3′,5′-triprenylflavanone, (2R,3R)7,4′-dihydroxy-8,3′,5′-triprenyldihydroflavanol, 5,7,2′,4′-tetrahydroxy-6,3′-diprenylisoflavone and 5,7,4′-trihydroxy-2′-methoxy-6,3′-diprenylisoflavone.