Two new phenylpropanoids from the resin of Styrax tonkinensis (Pierre) Craib ex Hartw

Two new phenylpropanoids, named stytonkinol A (1) and stytonkinol B (2), have been isolated from the resin of Styrax tonkinensis (Pierre) Craib ex Hartw. Their structures were determined by spectroscopic analysis, including 1D and 2D NMR, and HR-ESI-MS. Two isolated compounds were assayed for cytotoxic activities against five tumor cell lines (HepG-2, A549, Hela, MCF-7, and PC-3) by Cell Counting Kit-8 (CCK-8) test in vitro. The cytotoxic effectiveness observed against Hela, and MCF-7 cell lines of compound 1 were superior or similar to the positive control cisplatin (IC₅₀ values of 40.95 and 47.36 μM), with IC₅₀ values of 26.75 and 45.16 μM, respectively, while it showed moderate cytotoxic activities against the HepG-2 and PC-3 cell lines. Compound 2 showed moderate cytotoxic activities on cells MCF-7 with IC₅₀ values of 57.1 μM.

Keywords: Cytotoxic activities; Phenylpropanoids; Resin; Styrax tonkinensis.