Difference in flavonoid and isoflavone profile between soybean and soy leaf.
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.
Ho
Hing Man
HM
Department of Biochemistry, The Chinese University of Hong Kong, Shatin, New Territories.
Chen
Ruo Yun
RY
Leung
Lai Kwok
LK
Chan
Franky L
FL
Huang
Yu
Y
Chen
Zhen-Yu
ZY
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
D005419:Flavonoids; D007529:Isoflavones; D010936:Plant Extracts; C065753:isoflavanone