New 2-o-methylrhamno-isoflavones from Streptomyces sp.
Chemical screening with extracts of Actinomycetes strains resulted in the detection, isolation and structure elucidation of five new isoflavone glycosides from Streptomyces sp. (GT 51173): 5-O-alpha-L-rhamnopyranosyl genestein (genestein G1, 1), 5-O-alpha-L-rhamnopyranosyl-7-O-[2-O-(methyl)-alpha-L-rhamnopyranosyl] genestein (genestein G2, 2), 7,4'-O-di-[2-O-(methyl)-alpha-L-rhamnopyranosyl] daidzein (daidzein G1, 3), 6-O-methyl-7-O-[2-O-(methyl)-alpha-L-rhamnopyranosyl] daidzein (daidzein G2, 4) and 7-O-[2-O-(methyl)-alpha-L-rhamnopyranosyl] daidzein (daidzein G3, 5). As a striking structural feature, 2-5 bear one or two alpha-L-rhamnopyranosyl sugar moieties with methoxy groups in an axial position at C-2.
Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Xian Nong Tan Street, Beijing 100050, P. R. China.
Jin-Feng
JF
Hu
Dirk
D
Wunderlich
Isabel
I
Sattler
Ralf
R
Thiericke
Susanne
S
Grabley
Xiao-Zhang
XZ
Feng
D007529:Isoflavones / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D013302:Streptomyces / Q000737:chemistry*
D007529:Isoflavones