Chem. Pharm. Bull. 53(12) 1600—1603 (2005)

(Euphorbiaceae) (Vietnamese name: Don mat troi) is a small plant, about 1 m high and endemic to eastern Indochina. Growing wild and also being cultivated as a medicinal and ornamental plant, the plant is characterized by the features that its leaves are nearly opposite, deep green above, and purple red beneath, and the margins denticulate. Its leaves are usually used in a Vietnamese folk medicine to treat furuncles, pruritus, prolonged diarrhoea, urethrorrhagia, and dysentery. Until now, there has been no information on glycosidic compounds from E. cochinchinensis var. cochinchinensis. This paper describes the isolation and structure elucidation of two new megastigmane glucosides (3, 4), together with seven known compounds (1, 2, 5—9) from the leaves of the title plant. The air-dried and powdered leaves of E. cochinchinensis var. cochinchinensis were extracted with MeOH at room temperature, and the successive partition of the concentrated MeOH extract between H2O and organic solvents of increasing polarity, n-hexane, EtOAc, and 1-BuOH, gave three corresponding soluble fractions. The 1-BuOH-soluble fraction was subjected to a general separation procedure (see Experimental) to give compounds 1—9. Excoecarioside A (3), an amorphous powder, gave a molecular formula of C19H32O8 at m/z 387.2028 ([M H] ) in the negative-ion high-resolution (HR)-FAB-MS. The IR spectrum indicated the presence of hydroxy (3368 cm ) and an a ,b-unsaturated ketone (1643 cm ) group. The H-, CNMR (Table 1), distortionless enhancement by polarization transfer (DEPT), and heteronuclear single quantum correlation (HSQC) spectra of 3 showed the presence of 13 carbons of a megastigmane skeleton and six carbons of b-glucopyranose [dC 104.3 (d), 77.8 (d), 77.6 (d), 74.8 (d), 71.3 (d), and 62.2 (t); anomeric proton: dH 4.15 (d, J 7.8 Hz)]. A similar 1600 Notes Chem. Pharm. Bull. 53(12) 1600—1603 (2005) Vol. 53, No. 12