Abstract: AimTo investigate the antidepressant constituents of Piper laetispicumC. DC. Methods The compounds were enriched by column chromatography on silica gel. Structural determination of the pure compounds was based on extensive analyses of modern spectroscopic methods including MS, HR-MS, UV, IR, 1D- and 2D-NMR spectra. The mouse forced swimming test was used for chasing antidepressant activity. ResultsThree amides were isolated and identified as N-isobutyl-(3,4-methylendioxyphenyl)-2E,4E,9E-undecatrienoamide (I), N-isobutyl-9-phenyl-2E,4E-nonadienamide (II) and N-isobutyl-7-phenyl-2E,4E-heptadienamide (III). ConclusionN-Isobutyl-(3,4-methylendioxyphenyl)-2E,4E,9E-undecatrienoamide (I) is a new compound named as laetispicine. N-Isobutyl-9-phenyl-2E,4E-nonadienamide (II) and N-isobutyl-7-phenyl-2E,4E-heptadienamide (III) were isolated for the first time as natural substance.