NEW PHYTOCONSTITUENTS FROM ORYZA SATIVA L. BRAN

Rice bran serves as an important functional food that has cholesterol-lowering and immunostimulating properties, cardiovascular health benefits and antitumor activity. Phytochemical investigation of a methanolic extract of rice bran gave three new phytoconstituents, characterised as 4,4,8β-trimethyl- 9-[13β,17β,21β-trimethyltridec-9(11)-enyl]-decalin-1-en-6-one-3β,27-olide (orizatriterpenolide, 4), β-Dxylopyranosyl- 1,2-dioleiate (1,2-dioleiyl-β-D-xyloside, 6) and ricinoleic acid-12-β-D-glucopyranoside (ricinoleic acid-5-O-β-D-glucoside, 7) together with the known compounds palmitic acid (1), stigmasterol (2), cerotic acid (3) and oleiyl-β-D-arabinopyranoside (5). The structures of all the isolated phytoconstituents were elucidated on the basis of the spectral data analysis and chemical reactions. The compounds 4 (triterpenic lactone), 5 (xylose diester) and 7 (ricinoleic acid-5-O-β-D-glucoside) were isolated for the first time from rice bran.