New alpha-pyrrolidinonoids and glycosides from Euphorbia humifusa

A phytochemical investigation on the constituents from Euphorbia humifusa Willd. has resulted in the isolation of three new alpha-pyrrolidinonoidal compounds, 5beta-methoxy-4beta-hydroxy-3-methylene-alpha-pyrrolidinone (1), 5beta-methoxy-4alpha-hydroxy-3-methylene-alpha-pyrrolidinone (2), and 5beta-butoxy-4alpha-hydroxy-3-methylene-alpha-pyrrolidinone (3), and three new glycosides including an indole glycoside, 3-(2-hydroxyethyl)-5-(1-O-beta-glucopyranosyloxy)-indole (4), an ionone glycoside, 3-oxo-7,8-dihydro-alpha-ionone-11-O-beta-glucoside (5), and a hemiterpene glycoside, 1-(4-hydroxy-2-methyl-2-buten-1-yl)-6- (3,4,5-trihydroxybenzoyl)-beta-d-glucose (6), along with 10 known compounds. Their structures were elucidated by analysis of 1D and 2D NMR spectral data. The structure of 1 was further confirmed by a single-crystal X-ray diffraction analysis.