Cytotoxic Meroterpenes: A Review

Abstract

Meroterpenes are mixed natural products. They consist of one terpene and one polyketide skeletons. Due to their structural varieties, meroterpenoids display diverse bioactivities, like anticancer, anti-inflammatory, antibiotic , and antifibrotic activities. Our aim is to highlight the importance of the meroterpenes which have been the most studied on and reported among the bioactive natural products last years. According to our literature survey, the three most effective meroterpene groups have been determined. One group is the meroterpenes isolated from the brown alga Sargassum siliquastrum: Sargachromanol E, D, and P have exerted strong cytotoxicity against AGS (gastric cancer cells), HT-29 (colorectal adenocarcinoma cancer cell), and HT-1080 (human fibrosarcoma cells) cell lines, with IC 50 values varying from 0.5 to 5.7 μg/mL [100]. The other most effective meroterpene is Eucalypglobulusal F, which is isolated from E. globulus fruit, has shown cytotoxicity against the human acute lymphoblastic cell line (CCRF-CEM) with an IC 50 value of 3.3 μM [89]. Also, the last one is 11-dehydroxy epoxyphomalin A (4), from the endophytic fungus Peyronellaea coffeae-arabicae FT238, which was obtained from the native Hawaiian plant Pritchardia lowreyana showed a strong antiproliferative effect with an IC 50 of 0.5 μM against OVCAR3 (Ovarian carsinoma cells) [102]. Conclusively, meroterpenes have potential nominees as an anticancer drug. Moreover, the structure of naturally isolated meroterpenes has a moderate anticancer activity that can easliy be modified by semi-synthetic ways due to their simple structures comparing to other natural compounds such as triterpenes or phenolic compounds.