Eleven indole alkaloids were isolated from the stem bark of Kopsia hainanensis, collected at Hainan island, China. They were: (—)-kopsinine, (—)-kopsininic acid, (—)-kopsinoline, kopsinilam, kopsanone, (+)-5,22 dioxokopsane, eburnamenine, (+ )-eburnamine, (—)-isoeburnamine, (+ )-tubotaiwine, and (+)-kopsoffine; A water extract of the Oriental crude drug "yokui-nin" (coix seeds), Coix lachryma-jobi var, ma-yuen seeds, disclosed a marked hypoglycemic action when administered to mice. Fractionation of the extract, by monitoring the pharmacological activity, led to isolation of three glycans, coixans A, B and C. These components elicited remarkable hypoglycemic effects in normal and hyperglycemic mice treated with alloxan.