Nobuyasu Matsuura

Isoflavones from stems of Euchresta horsfieldii

Abstract Four new prenyl(=3-methyl-2-butenyl)isoflavones, euchrenones b6-b9, were isolated from stems of Euchresta horsfieldii from Thailand in addition to four known isoflavones (warangalone, osajin, 6,8-di(3-methyl-2-butenyl)genistein and 8-O-methylretusin) and two pterocarpans (maackiain and sophoracarpan B). 1H NMR spectral properties of regio-isomers, such as warangalone and osajin, are also discussed.

Flavonoids in the roots of Euchresta horsfieldii in Thailand

Abstract In addition to known compounds [kushenol E, 6,8-di(3,3-dimethylally)genistein, osajin, warangalone, derrone 4′- O -methyl ether, alpinumisoflavone 4′-methyl ether and feruloyl hexadecayl ester], three new flavonoids were isolated from the roots of Euchresta horsfieldii in Thailand. By means of the spectroscopic analysis, the structures of new compounds were characterized as 5,2′,4′-trihydroxy-6-(3,3-dimethylallyl-6‴,6‴-dimethylpyrano[2‴,3‴: 7,8)] flavanone(euchrenone a 9 ),5, 4′-dihydroxy-6-(3,3-dimethylallyl)-5‴-hydroxyisoproyldihydrofurano [2″,3″: 7,8]isoflavone (euchrenone b 10 )and 2-methoxymaackiain.

Two flavanones from Euchresta horsfieldii

Abstract Two new prenylflavanones, euchrenones a 7 and a 8 , were isolated from roots and stems of Euchresta horsfieldii distributed in Yunnan, China, in addition to a known flavanone (glabrol), a pterocarpan (maackiain) and a ferulic acid ester. By means of spectroscopic analysis, the structures of euchrenones a 7 and a 8 were determined to be 7,2′,4′-trihydroxy-8-γ,γ-dimethylallyl- and 7,2′-dihydroxy-8,5′-di(γ,γ-dimethylallyl)-4′-methoxyflavanone, respectively.

Four Flavonoids in the Roots of Euchresta formosana.

Abstract Four new flavonoids from the roots of Euchresta formosana were characterized as 5,5′-dihydroxy-8-γ,γ-dimethylallyl-{(6″,6″-dimethylpyrano(2″,3″:7,6)}-{(6 ,6 -dimethylpyrano-(2 ,3 :4′,3′)}-coumaronochromone (euchretin D), 5,5′-dihydroxy-6-γ,γ-dimethylallyl-{(6″,6″-dimethylpyrano(2″,3″: 7,8)}-{(6 ,6 -dimethyl-pyrano(2 ,3 :4′,3′)}-coumaronochromone euchretin E), 5,2′-dihydroxy-8-γ,γ-dimethylallyl-{(6″,6″-dimethylpyrano (2″,3″:7,6)}-{(6 ,6 -dimethylpyrano-(2 ,3 :4′,5′)}flavanone euchrenone a11 and 5,2′-dihydroxy-6-γ,γ-dimethylallyl-{(6″,6″-dimethylpyrano(2′,3″:7,8)}-{6 ,6 -dimethylpyrano(2 ,3 :4′,5′)} flavanone (euchrenone a12) by means of spectroscopic analysis.

Flavonoids and a benzofuran in roots of Euchresta tubulosa

Abstract Five new flavonoid compounds and a new benzofuran were isolated from the roots of Euchresta tubulosa in addition to eight known compounds [euchrenones a 1 , a 4 and b 2 and euchretins A–E]. The structures of the new compounds were characterized as 8-γ,γ-dimethylallyl-5-hydroxy-{6″,6″-dimethylpyrano(2″,3″:7,6)}-{6″″,6″″-dimethylpyrano(2″″,3″″:4′,3′)} flavanone (euchrenone a 14 ), 6-γ,γ-dimethylallyl-5-hydroxy-{6″,6″-dimethylpyrano-(2″, 3″:7,8)}-{6″″,6″″-dimethylpyrano(2″″,3″″:4′,3′)}flavanone (euchrenone a 15 ), 8-γ,γ-dimethylallyl-5,2′-dihydroxy-{6″, 6″-dimethylpyrano(2″,3″:7,6)}-{6″″,6″″-dimethylpyrano(2″″,3″″:4′,3′)}isoflavone (euchrenone b 18 ), 6-γ,γ-dimethyl-allyl-5, 2′-dihydroxy-{6″,6″-dimethylpyrano(2″,3″:7,8)}-{6″″,6″″-dimethylpyrano(2″″,3″″:4′,3′)}isoflavone (euchrenone b 17 ), 6,3′-di(γ,γ-dimethylallyl)-5,4′,5′-trihydroxy-{6″,6″-dimethylpyrano(2″,3″:7,8)}coumaronochromone (euchretin I) and 2-[{6″,6″-dimethylpyrano(2″,3″:2′,3′)}-{6″′,6″′-dimethylpyrano(2″′,3″′:4′,5′)}phenyl] -5,6-methylenedioxybenzofuran (euchrestafuran), respectively, by means of spectroscopic analysis.

Coumaronochromones in the roots of Euchresta japonica

Abstract In addition to eight known compounds [euchrenones a 6 , a 11 and a 12 , glabrol, euchretins AC, and lespedezaflavanone C], three new coumaronochromones were isolated from the roots of Euchresta japonica . By means of spectroscopic analysis, the structures of new compounds were characterized as 5,7,4′,5′-tetrahydroxy-6,8-di(γ,γ-dimethylallyl)-, 5,4′,5′-trihydroxy-6-γ,γ-dimethylallyl-[6″,6″-dimethylpyrano(2″,3″:7,8)]-, and 5,7,5′-trihydroxy-8-γ,γ-dimethylallyl-[6″′,6″′-dimethylpyrano(2″′3,3″′:4′,3′)]-coumaronochromone, and were named euchretins F, G and H, respectively.

A prenylated flavanone from roots of Maackia amurensis subsp. Buergeri

Abstract A prenylated flavanone was isolated from the roots of Maackia amurensis subsp. buergeri , in addition to seven known compounds; daidzein, formononetin, ononin, maackiain, trifolirhizin, isomedicarpin -9- O -glucoside and 5-hydroxysophoranone. The structure of the new compound was characterized as 8,5′-di (γ,γ-dimethylallyl-5,2′,4′-trihydroxy-7-methoxyflavanone (maackiaflavanone).

Chemotaxonomic approach to the genus Euchresta based on prenylflavonoids and prenylflavanones in roots of Euchresta formosana

Abstract The distribution of prenylflavonoid compounds in the genus Euchresta was surveyed and the chemotaxonomic value of there compounds assessed. A new prenylflavanone(1), euchrenone a10, the separation of which has been unsuccessful up to now, was isolated from the roots of Euchresta formosana (Leguminosae) in addition to two known flavanones (lupinifolin and sophranochromene). By means of spectroscopic analysis, the structure of euchrenone a10 was determined to be 5,7-dihydroxy-8-γ, γ-dimethylallyl-[6‴, 6‴-dimethylpyrano(2‴, 3‴: 4′, 3′)]flavanone. Among known flavanones, sophoranochromene in unusual in having two C5-units (a γ, γ-dimethylallyl group and a dimethylpyran ring) on the B-ring. Compounds di-prenylated on the B-ring such as sophoranochromene have been isolated from the genus Euchresta for the first time, and the chemotaxonomic value of this is evaluated.

Isoflavones from roots of Euchresta japonica

Abstract Seven new isoflavones, named euchrenones b 10 –b 16 were isolated from the roots of Euchresta japonica . By means of spectral data, the inuctures were determined to be 5,5′-dihydroxy-2′-methoxy-8-γ,γ-dimethylallyl-[6″,6″-dimethylpyrano(2″,3″:7,6)]-[6″“,6″”-dimethylpyrano(2″“,3″”:4′,3′)]-, 5,5′-dihydroxy-2′methoxy-6-γ,γ-dimethylallyl[6″,6″-dimethylpyrano(2″,3″:7,8)]-[6″“,6″”-dimethylpyrano-(2″“,3″”:4′,3′)]-, 5,4′-dihydroxy-′-methoxy-8,3′-di(γ,γ-dimethylallyl)-[6″,6″-dimethylpyrano(2″,3″:7,6)]-, 5,4′-dihydroxy-2′-methoxy-6,3′-di(γ,γ-dimethylallyl)-6″,6″-dimethylpyrano(2″,3″:7,8)]-, 5,7,4′-trihydroxy-2′-methoxy-6,8,3-tri-(γ,γ-dimethylallyl)-, 5,7,4′-trihydroxy-2′-methoxy-6,8-di(γ,γ-dimethylallyl)- and 5,2′,4′-trihydroxy-6,3′-di(γ,γ-dimethylallyl)-[6″,6″-dimethylpyrano(2″,3″:7,8)]isoflavone, respectively.

Phylogenetic analysis in genus Euchresta based on secondary metabolites

Abstract Two different phylogenetic relationships among Euchresta species have been proposed on the basis of general morphology. To confirm the relationships, we applied a cladistic analysis based on the secondary metabolites in the genus. Our accumulated data on the structures of prenylflavonoid compounds in the stems and the roots of all Euchresta species revealed the presence of presumed enzymes which contribute to their formation. The enzymes were used as characters in the phylogenetic analysis of Euchresta plants and a relative, Sophora tonkinensis. The cladistic analysis and the results of relative ratios of O- or C-apigenin glycosides in the leaves led us to propose new evolutionary trends in Euchresta.