Two new iridoid glycosides, named productasperulosidic acid butyl ester (1) and E-6-O-3-hydroxy-p-methoxycinnamoyl scandoside methyl ester (2), along with nine known ones (3-11), were isolated from Hedyotis diffusa Willd. The structures of them were elucidated by extensive 1D, 2D NMR and HR-ESI-MS spectral data. Compounds 1-11 showed no significant cytotoxic activity against HeLa cells.
Keywords: E-6-O-3-hydroxy-p-methoxycinnamoyl scandoside methyl ester; Hedyotis diffusa; Rubiaceae; asperulosidic acid butyl ester; cytotoxic activity; iridoid glycoside.