Cytotoxic sesquiterpenes and diterpenes from the rhizomes of Curcuma zedoaroides Chaveer. & Tanee

A phytochemical investigation of Curcuma zedoaroides rhizomes resulted in the isolation of ten sesquiterpenes (1–10) and two diterpenes (11−12). The structure of compounds 1–12 was identified as phaeocaulisin E (1), zedoarondiol (2), isozedoarondiol (3), isoprocurcumenol (4), neoprocurcumenol (5), procurcumenol (6), 1-epi-procurcumenol (7), aerugidiol (8), curcumenol (9), curcumenone (10), curcuminol E (11), and zerumin A (12) using MS and NMR methods. Remarkably, all these compounds were found in C. zedoaroides for the first time and their chemotaxonomic significance was also discussed. Moreover, the fractionated extracts of C. zedoaroides (n-hexane, ethyl acetate, and water) were demonstrated to have effects on eight cancer cell lines (A549, MCF-7, HT-29, MB49, HepG2, MDA-MB231, JB6-C141, and K562), exhibiting IC₅₀ values ranging from 5.43 to 11.96 μg/mL. Compounds 1–9 and 11−12 displayed significant activity against five cancer cell lines (A549, MCF-7, MDA-MB231, HL-60, and HepG2), with IC₅₀ values ranging from 3.13 μM to 30.10 μM. The most potent effect was observed in the A549 cell line (IC₅₀: 3.13–13.54 μM).