Abstract: Eleven compounds were isolated from the stem and leaf of Piper austrosinense by using the method of Toyopearl HW-40c,silica gel,ODS,MCI and pre-HPLC,including one benzaldehyde derivative,one benzoic acid derivative,three phenylpropanoids,two flavonoids,two alkaloids,two sesquiterpenes,and one ionone.The compounds were identified as protocatechualdehyde (1),protocatechuate (2),4-allyl catechol (3),caffeic aldehyde (4),cynaroside (luteolin-7-O-β-D-glucoside,5),rhoifolin (apigenin-7-O-neohesperidoside,6),pipernonaline (7),indole-3-formic acid (8),aromadendrane-4β,10β-diol (9),(-)-clovane-2,9-diol (10),and (3S,5R,6S,7E)-3,5,6-trihydroxy-7-megastigmen-9-one (11).Compounds 5-11 were firstly isolated from the title plant.Among them,it is the first time to report compounds 5,6,8-11 isolated in the genus Piper.In addition,compound 7 showed selective butyrylcholinesterase inhibitory activity with IC₅₀ value of 29.06 ± 0.32 μM,while other compounds showed no acetylcholinesterase and butyrylcholinesterase inhibitory activities at the concentration of 30 μM.The cytotoxic activities of all compounds against HepG2 cell line were tested by MTT assay.However,no compounds showed cytotoxicity at the concentration of 30 μM.

Key words: Piper austrosinense, chemical constituents, Piper, cholinesterase inhibitory activity