摘要：

Chemical profiling and characterization of bioactive metabolites of the rhizome Curcuma xanthorrhiza from Tawau was investigated. It involved bioassay (Antibacterial and Antioxidant) guided separation of bioactive metabolites the isolation, purification and characterization of the active metabolite. Its yellow essential oil was extracted via hydrodistillation and 30 constituents were identified with the aid of GCMS. The major constituent of the essential oil was Cycloisolongifolene (8, 9-dehydro-9-formyl) and it makes up 40.79% of the essential oil. Disc diffusion assay showed that essential oil had minimal antibacterial activity against Clostridium cellobioparum. Dark brown crude extract paste was extracted via Soxhlet extraction. A DPPH antioxidant test was carried out on the crude producing a high average scavenging activity of 92.03% and an average total antioxidant activity of 0.57 after 24 h. This implies the strong presence of antioxidant compounds within the crude extract. Isolated active compound was obtainedas pale yellow paste (Compound A). Preliminary PTLC bioassay showed strong antibacterial properties with four out of five positive inhibitions. The bacteria that were positively inhibited are Clostridium cellobioparum, Clostridium sordelli, Clostridium noryi and Vibrio alginolyticus. Structure elucidation via ¹H-NMR, ¹³3C-NMR and FTIR showed that compound A consists of a benzene ring, 3 methyls and an exo-methylene and is most likely to be a phenolic compound with an alkyl branch.

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