Six new iridoid glycosides from the whole plants of Hedyotis diffusa .

Six new iridoid glycosides were isolated from the ethyl acetate fraction of the whole plants of Hedyotis diffusa Willd. They were identified as E -6- O-p -methoxycinnamoyl-10- O -acetyl scandoside acid methyl ester ( 1 ), Z -6- O-p -methoxycinnamoyl-10- O -acetyl scandoside acid methyl ester ( 2 ), E -6- O -caffeoyl scandoside methyl ester ( 3 ), E -6- O - p -coumaroyl-6'- O -acetyl scandoside methyl ester ( 4 ), Z -6- O - p -coumaroyl-6'- O -acetyl scandoside methyl ester ( 5 ), and E -6- O - p -coumaroyl-4'- O -acetyl scandoside methyl ester ( 6 ). The structures of them were elucidated based on unambiguous spectroscopic data (UV, IR, HRESIMS, and NMR). They were screened for anti-inflammatory effect, antioxidant effect, antitumor effect, and neuroprotective effect and did not show potent activities.