A new benzophenanthridine alkaloid and other bioactive constituents from the stem bark of Zanthoxylum heitzii.

Heitziquinone ( 7 ), a new benzophenanthridine alkaloid, together with five known compounds; isoarnottianamide ( 5 ), rhoifoline B ( 6 ), isobauerenol ( 8 ), 6-hydroxypellitorine ( 9 ) and sylvamide ( 10 ), were isolated as minor compounds from the hexane extract of stem bark from Zanthoxylum heitzii . Four previously reported compounds ( 1 – 4 ) were found, as well. Compounds 5 and 7 were both found to exist as 4:1 mixtures of two atropisomers. The structures were elucidated by 1D and 2D NMR spectroscopy and by mass spectrometry. Compounds 5 – 10 were identified for the first time in this species, and they are all rare natural compounds. Pellitorine ( 4 ), one of the main compounds from the hexane bark extract, was found to be responsible for the brine shrimp larvae toxicity (LC 50 37 μM, 8 μg/ml) of the crude extract (LC 50 24 μg/ml). Low cytotoxicity against a macrophage cell line was observed. [ABSTRACT FROM AUTHOR]