Terpenoids from Myrrh and Their Cytotoxic Activity against HeLa Cells

The oleo-gum resin of Commiphora myrrha (Nees) Engl. has a long history of medicinal use, although many of its constituents are still unknown. In the present investigation, 34 secondary metabolites were isolated from myrrh resin using different chromatographic techniques (silica flash chromatography, CPC, and preparative HPLC) and their structures were elucidated with NMR spectroscopy, HRESIMS, CD spectroscopy, and ECD calculations. Among the isolated substances are seven sesquiterpenes (1-7), one disesquiterpene (8), and two triterpenes (23, 24), which were hitherto unknown, and numerous substances are described here for the first time for C. myrrha or the genus Commiphora. Furthermore, the effects of selected terpenes on cervix cancer cells (HeLa) were studied in an MTT-based in vitro assay. Three triterpenes were observed to be the most toxic with moderate IC₅₀ values of 60.3 (29), 74.5 (33), and 78.9 µM (26). Due to the different activity of the structurally similar triterpenoids, the impact of different structural elements on the cytotoxic effect could be discussed and linked to the presence of a 1,2,3-trihydroxy substructure in the A ring. The influence on TNF-α dependent expression of the intercellular adhesion molecule 1 (ICAM-1) in human microvascular endothelial cells (HMEC-1) was also tested for 4-6, 9-11, 17, 18, 20, and 27 in vitro, but revealed less than 20% ICAM-1 reduction and, therefore, no significant anti-inflammatory activity.

Linderolide U, a new sesquiterpene from Lindera aggregata root

A new sesquiterpene, namely linderolide U (1), was isolated from the root of Lindera aggregata (Sims) Kosterm along with five known sesquiterpenes (2-6). The structures of the obtained compounds were identified by spectroscopic methods, specifically nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). The acquired data were compared with those previously reported in the literature. The anticancer effects of the isolated natural products were studied using the HCT116 human colon cancer cell line. Compound 5 was found to significantly suppress cell proliferation, which was associated with induction of apoptosis and cell cycle arrest (G2/M and S phase). The findings of the present study suggest derivative 5 as a potential agent for the treatment of colon cancer.