Oryzasesterpenolide from the Hulls of Oryza sativa and Complete NMR Assignments of Momilactones A, B and Tricin

Abstract

From the hulls of Oryza sativa was isolated one new compound oryzasesterpenolide (1) along with nine compounds hentriacontane, 1-tetratriacontanol, b-sitosterol, momilactones A, B, tricin, b-sitosterol-3-O-b-D-glucuronoside, 3,7-dimethyl-n-octan-1-yl benzoate and b-sitosterol-3-O-b-D-glucoside. The structure of the new compound is elucidated by 500 MHz NMR using 1D and 2D spectral methods viz., ¹H, ¹³C, ¹H-¹H COSY and HETCOR aided by EIMS, FABMS and IR. The complete ¹H and ¹³C NMR assignments of momilactones A, B, tricin and 3,7-dimethyl-n-octan-1-yl benzoate are reported.