Anonazepine, a new alkaloid from the leaves of (Annonaceae).

From the CHCl-soluble extract of L. (Annonaceae) leaves, one new 3-benzazepine-type alkaloid, anonazepine (), and four known aporphine-type alkaloids, (+)-laurotetanine (), (+)-norglaucine (), (-)-xylopine (), and lanuginosine (), were isolated. Except for (-)-xylopine (), these remaining known alkaloids were first reported in . The structures of the isolated alkaloids were established by 1D and 2D NMR spectroscopy and MS, as well as comparison with literature data. The new 3-benzazepine-type alkaloid existed in an inseparable mixture of two equilibrium conformers. Its absolute configuration was determined based on comparing their experimental and calculated ECD data. The anti-inflammatory activity of the isolated alkaloids was investigated, but none of the alkaloids showed a significant result.