Title: Rhapontin
CAS Registry Number: 155-58-8
CAS Name: (
E)-3-Hydroxy-5-[2-(3-hydroxy-4-methoxyphenyl)ethenyl]phenyl b-D-glucopyranoside
Synonyms: 4¢-methoxy-3,3¢,5-stilbenetriol 3-glucoside; rhaponticin; ponticin
Molecular Formula: C21H24O9
Molecular Weight: 420.41
Percent Composition: C 59.99%, H 5.75%, O 34.25%
Literature References: From root of
Rheum rhaponticum L.,
Polygonaceae: Hesse,
J. Prakt. Chem. 77, 321 (1908); Schürhoff, Plettner,
Arch. Pharm. 275, 281 (1937). On hydrolysis yields rhapontigenin and glucose: Kawamura,
J. Pharm. Soc. Jpn. 58, 405 (1938),
C.A. 32, 66554 (1938). Constitution of rhapontigenin: Takaoka,
Proc. Imp. Acad. Tokyo 16, 408 (1940),
C.A. 35, 13992 (1941).
Properties: Crystals, dec 236-237°. [a]D32 -59.5° (acetone). Exhibits bright blue fluorescence. Sol in dil alcohol, hot acetone, hot water; slightly sol in ether, alc, acetone, cold water; practically insol in benzene, petr ether, chloroform.
Optical Rotation: [a]D32 -59.5° (acetone)