A new tricyclic alkaloid from twigs of Cassia fistula and its cytotoxicity / 中草药

Objective: To study the chemical constituents in the twigs of Cassia fistula. Methods: The chemical constituents in the twigs of C. fistula were isolated by silica gel, Sephadex LH-20 column chromatography, and RP-HPLC methods. And their structures were elucidated by using various spectroscopic techniques, including extensive 1D and 2D NMR techniques. Results: A new tricyclic alkaloid, named as cassiarin L (1) was isolated from 95% ethanol extract of the twigs of C. fistula. Conclusion: Compound 1 is a new compound and it displays obvious cytotoxicity against NB4, SH-SY5Y, PC3, A549, and MCF7 cells with IC50 values of 1.8, 2.6, 3.5, 4.2, and 2.3 μmol/L, respectively.