Antiproliferative activity of compounds isolated from the root bark of Lannea acida in multiple myeloma cell lines.

Lannea acida A. Rich. is a native plant of West Africa used in traditional medicine against diarrhea, dysentery, rheumatism, and women infertility. Eleven compounds were isolated from the dichloromethane root bark extract using various chromatographic techniques. Among those, nine compounds have not been previously reported, i.e. one cardanol derivative, two alkenyl 5-hydroxycyclohex-2-en-1-ones, three alkenyl cyclohex-4-ene-1,3-diols, two alkenyl 7-oxabicyclo[4.1.0]hept-4-en-3-ols, and one alkenyl 4,5-dihydroxycyclohex-2-en-1-one, together with two known cardanols. The structure of the compounds was elucidated using NMR, HRESIMS, ECD, IR, and UV. Their antiproliferative activity was evaluated in three multiple myeloma cell lines: RPMI 8226, MM.1S, and MM.1R. Two compounds showed activity in all cell lines with IC50 values < 5 µM. Further investigations are needed to understand the mechanism of action.