Piperolactam C

J Nat Prod. 2007 Dec;70(12):2036-9.

Antifungal amides from Piper scutifolium and Piper hoffmanseggianum.[Pubmed: 18031016 ]

METHODS AND RESULTS:
Chromatographic fractionation of a dichloromethane extract from the leaves of Piper scutifolium yielded two new isobutyl amides, scutifoliamide A ( 1) and scutifoliamide B ( 2), together with the known compounds Piperolactam C ( 3), piperovatine ( 4), piperlonguminine ( 5), corcovadine ( 6), isopiperlonguminine ( 7), and isocorcovadine ( 8). From the dichloromethane extract from the leaves of P. hoffmannseggianum two new isobutyl amides, hoffmannseggiamide A ( 9) and hoffmannseggiamide B ( 10), were obtained together with the known compounds isopiperlonguminine ( 7) and isocorcovadine ( 8), sitosterol, and stigmasterol. The structures of the new compounds were established on the basis of spectroscopic data analysis.
CONCLUSIONS:
The inhibitory activity of compounds 1-10 against the growth of the fungi Cladosporium sphaerospermum and C. cladosporioides was determined by bioautography.

Planta Med. 2005 Jun;71(6):535-42.

New cytotoxic cyclobutanoid amides, a new furanoid lignan and anti-platelet aggregation constituents from Piper arborescens.[Pubmed: 15971125 ]

METHODS AND RESULTS:
Three new cyclobutanoid amides with trans-trans-trans configurations, piperarborenine C, piperarborenine D and piperarborenine E, and a new furanoid lignan, (+)-arborone, together with twelve known compounds, were isolated from the stems of Piper arborescens. The structures of these new compounds were determined by means of spectral analyses. Piperarborenine C, (+)-diayangambin, piplartine, piperolactam B, Piperolactam C, aristolactam BIII, goniothalactam, and methyl trans-3,4,5-trimethoxycinnamate possessed anti-platelet aggregation activity in vitro.
CONCLUSIONS:
Among them, piplartine showed the most potent anti-platelet aggregation activity induced by collagen and showed an IC50 value of 21.5 microM. Piperarborenines A - E, piperarborenine, aristololactam BIII and goniothalactam showed significant cytotoxic activity (IC50 values < 4 microg/mL) against P-388, HT-29 and A549 cell lines in vitro.