A saponin conjugated with 2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one from Dolichos lablab.
A new 2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP)-conjugated saponin, lablab saponin I, was isolated from the hypocotyl of hyacinth bean (Dolichos lablab). The structure was elucidated by 1H NMR and 13C NMR spectroscopy and chemical techniques as 3-O-[alpha-L-rhamnopyranosyl- (1-->2)-beta-D-galactopyranosyl(1-->2)-beta-D-glucuronopyranosyl(1 -->)]-22-O- [2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one(2'-->)]-3 beta, 22 beta, 24-trihy-droxyolean-12-en-28-al. SOD (superoxide dismutase)-like activity depended upon the DDMP group and the aldehyde group (C-28) of the aglycone was observed in the order of lablab saponin I > glutathione > soyasaponin beta g > maltol. The soybean saponin Bb, lacking the DDMP moiety was found not to exhibit the SOD-like activity.
Yoshiki
Y
Y
Department of Applied Biological Chemistry, Faculty of Agriculture, Tohoku University, Miyagi, Japan.
Kim
J H
JH
Okubo
K
K
Nagoya
I
I
Sakabe
T
T
Tamura
N
N
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009828:Oleanolic Acid / Q000031:analogs & derivatives*; D010944:Plants / Q000737:chemistry*; D012503:Saponins / Q000737:chemistry* / Q000302:isolation & purification; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013482:Superoxide Dismutase / Q000378:metabolism
C093057:3-O--(rhamnopyranosyl-1-2-galactopyranosyl-1-2-glucuronopyranosyl-1-)-22-O-(2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyrano-4-one-2'-)-3,22,24-trihydroxy-olean-12-en-28-al; D012503:Saponins; D009828:Oleanolic Acid; D013482:Superoxide Dismutase