13C NMR-based dereplication analysis of cytotoxic styryl lactones from Goniothalamus giganteus against OSCC

Styryl lactones, which are ubiquitous in the genus Goniothalamus, have emerged as promising candidates in combating cancer due to their ability to inhibit the growth of cancer cells. Therefore, this study aimed to rapidly identify styryl lactones from the bark of a Malaysian plant, Goniothalamus giganteus, by combining conventional phytochemical methods with 13C NMR-based dereplication analysis to speed up the chemical profiling and structural elucidation processes. From the 13C NMR-based dereplication analysis of Goniothalamus giganteus using MixONat software, a total of nineteen compounds were identified; two terpenes (1-2), one flavonoid (3), and sixteen styryl lactones (4-19). Purification exercise led to the isolation of thirteen compounds, including two new compounds possessing a bis-styryllactone skeleton; goniogigantone A (20) and goniogigantone A (21), along with other eleven known compounds (1, 3, 9, 11, 12, 14, 17, 22-25). Altholactone (11), the major compound isolated from this species had showed the highest cytotoxic effect against both H103 and H400 oral squamous cell carcinoma (OSCC) cell lines with IC50 values of 5.68 μM and 5.08 μM, respectively via MTT assay.