Chemical phytoconstituents of Amyris pinnata

Amyris is a plant genus usually very aromatic. Some species have been used for timber and as a source of incense and oil with several attributed medicinal properties. As part of our research on Colombian Rutaceae plants, a phytochemical exploration was carried out on Amyris pinnata Kunth (bark and leaves), as well as the antitumor activity evaluation on P-388, M-17 and H-116 tumor cell lines. So far, only a work had described the isolation and the cytotoxic activity of five coumarins and three butyrolactone lignans from A. pinnata leading to the identification of the cytotoxic lignan austrobailignan-1. Herein described is the isolation of six lignans, three coumarins, a sesquiterpene, an oxazole alkaloid and a prenylated flavonoid, whose chemical structures were established by fully analyses of spectroscopic data (1D and 2D NMR, MS) in comparison with data in the literature. All compounds exhibited antitumor activity at different levels. Butyrolactone and aryltetralin lignans exhibited the best cytotoxic activity (ED₅₀= 2.0 – 20µM) against cell lines. Sesquiterpene was only active against H-116 cell line. Remaining test compounds exhibiting low cytotoxic activity.