Chem. Pharm. Bull., 47(10),1444-1447, October 1999
Three new compounds; 4'-O-b-D-glucopyranosyl rosmarinic acid (2), 4,4'-O-di-b-D-glucopyranosyl rosmarinic acid(3) and 2R-O-(4'-O-b-D-glucopyranosyl caffeoyl)-3-(4-hydroxyphenyl) lactic acid named as 4'-O-b-D-glucopyranosyl isorinic acid (4) were isolated together with rosmarinic acid (1) from the fruit of Helicteres isora L. (Sterculiaceae), an Indonesian medicinal plant. The structures of these compounds, including the absolute stereochemistry of 4, were elucidated by spectroscopic analysis and chemical means. Compound 3 had greater scavenging activity against superoxide anion produced with xanthine and xanthine oxidase (XOD) than rosmarinic acid (1).
Key words Helicteres isora; isorinic acid; rosmarinic acid glycoside; rosmarinic acid; Sterculiaceae