Chemical Constituents and Biological Activities of Curcuma Xanthorrhiza and Curcuma Heyneana

Abstract

Five compounds were isolated from Curcuma xanthorrhiza. The hexane extract afforded three pure compounds, which were identified as α- curcumene (21), germacrone (17) and zederone (66), while dichloromethane extract gave yellow powder product, which was characterized as curcumin (5) together with colourless oil, xanthorrhizol (16). The studies on Curcuma heyneana afforded four compounds. The hexane extract yielded oxycurcumenol epoxide (64), which is a new natural product, isocurcumenol (31) and curcumenol (32). In addition, dichloromethane extract produced stigmasterol (65). The following biological activities; larvicidal, cytotoxicity and antimicrobial activities carried out on these plants have not been reported previously. However the antioxidant activity has been reported. The results of bioactivity tests revealed that some of the plant crude extracts showed strong biological activities. Nevertheless, most of the isolated pure compounds showed only weak to moderate activity. Larvicidal test results both on the plants crude extracts showed that non polar extracts exhibited high toxicity with a LC50 value between 26.4 μg/ml and 34.9 μg/ml. On the other hand, curcumin (5) and curcumenol (32) showed antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa. The results obtained for antioxidant activity test revealed that curcumin (5) possessed stronger antioxidant activity, while the isolated pure compounds from C. heyneana were not active in the assay. Cytotoxicity activity on the isolated pure compounds from C. heyneana including oxycurcumenol epoxide (64), curcumenol (32) and isocurcumenol (31) exhibited moderate cytotoxic activity with IC50 values 11.9, 12.6 and 13.3 μg/ml, respectively, while curcumin (5) showed strongest inhibitory activity with IC50 value 9.1 μg/ml.