Two new sesquiterpenes from the stems of Miliusa velutina

From the ethyl acetate extract of the stems of Miliusa velutina, seven compounds (1-7) were isolated, including two new compounds such as mivelutina A acid (1), mivelutina B acid (2) and one known compound mivelutina B methyl ester (3). For this NMR data were not known previously. Their relative structures were elucidated based on NMR spectroscopic analysis. The absolute configuartions were determined based on DFT calculations of ¹³C chemical shifts. All of the seven compounds were screened for their in vitro cytotoxic activities against HepG2 cell line using the SRB assay. Epoxyconiferyl alcohol (7) showed the highest potential for the cytotoxicity of cancer cell lines HepG2 with the IC₅₀ values of 95.94 μg/mL (527 μM).