title: Difference in flavonoid and isoflavone profile between soybean and soy leaf.
abstract: The present study was to compare the flavonoid profile between soybean and soy leaves. Soybean was most abundant in malonyl-genistin followed by malonyl-daidzin, genistin, daidzin, genistein and daidzein in a decreasing order. In contrast, soy leaves contained only trace amounts of malonyl-genistin and genistin, but they had the six unknown flavonoids that were absent in soybean. The six unknown compounds were isolated by using various chromatographic techniques and the structures were identified by studying their varying spectra of ultraviolet (UV), infrared (IR), Mass, 1H-NMR and 13C-NMR. It was found that the six unknown compounds were all kaempferol glycosides namely kaempferol-3-O-alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->6)-beta-D-galactopyranoside, kaempferol-3-O-(2,6-di-O-alpha-rhamnopyranosyl)-beta-galactopyranoside, kaempferol-3-O-alpha-L-rhamnopyranosyl (1-->6)-beta-D-galactopyranoside, kaempferol-3-O-digalactopyranoside, kaempferol-3-O-diglucopyranoside and kaempferol-3-O-rutinoside. It was concluded that the flavonoids in soy leaves were mainly kaempferol glycosides, whereas those in soybean were mainly isoflavone glycosides and derivatives.
authors.affiliation: Department of Biochemistry, The Chinese University of Hong Kong, Shatin, New Territories.
authors.forename: Hing Man
authors.initials: HM
authors.lastname: Ho
authors.forename: Ruo Yun
authors.initials: RY
authors.lastname: Chen
authors.forename: Lai Kwok
authors.initials: LK
authors.lastname: Leung
authors.forename: Franky L
authors.initials: FL
authors.lastname: Chan
authors.forename: Yu
authors.initials: Y
authors.lastname: Huang
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Chen
mesh_terms: D005419:Flavonoids / Q000032:analysis* / Q000737:chemistry; D007529:Isoflavones / Q000032:analysis / Q000737:chemistry; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D013025:Glycine max / Q000737:chemistry
chemical_list: D005419:Flavonoids; D007529:Isoflavones; D010936:Plant Extracts; C065753:isoflavanone