Cytotoxic pyridone alkaloids from the leaves of Piper aborescens.

Bioactivity-guided fractionation of a CHCl3 extract of the leaves of Piper aborescens afforded a new cytotoxic pyridone alkaloid, N-(3-methoxy-4,5-methylenedioxydihydrocinnamoyl)-delta 3-pyridin-2-one [1], as well as three known cytotoxic pyridone alkaloids, N-(3-methoxy-4,5-methylenedioxycinnamoyl)-delta 3-pyridin-2-one [2], piplartine [3], and piplartine dimer A [4].