Prenylated 4-phenylcoumarins and 4-alkylcoumarins from Kielmeyera argentea and their cytotoxic activity

Abstract

Two new prenylated 4-phenylcoumarins, named kielcoumarin A (1) and kielcoumarin B (2) together with three known compounds, mammea B/BA (3), mammea B/BA cyclo F (4) and ferruol A (5), were obtained from stems and roots of Kielmeyera argentea (Calophyllaceae). Their structures were elucidated based on spectroscopic data. Cytotoxic activity of the 4-alkylcoumarins 3-5 was evaluated in vitro against human U251 glioblastoma cell line. Compound 3 showed significative activity with EC₅₀ value of 6.6 μM while compounds 4 and 5 showed respective EC₅₀ values of 52.0 and 37.0 μM.

Keywords: 4-alkylcoumarin; 4-phenylcoumarin; Calophyllaceae; Human U251 glioblastoma cell line; Kielmeyera argentea; ferruol A (PubChem CID: 12309873).; mammea B/BA (PubChem CID: 5489487); mammea B/BA cyclo F (PubChem CID: 101967071).