LC-HRMS identification of sterols and triterpenes compounds from antitrypanosomal active fractions of Ocimum gratissimum Linn from Benin

The bio-guided study showed the ethyl acetate fractions of the crude ethanolic extracts of leaves and seeds of Ocimum gratissimum in full flowering stage as the most active against Trypanosoma brucei brucei. The LC/HRMS analysis of these fractions allowed us to identify 13 molecules of the sterol and triterpene families, namely: asian, abietic, trans-ferulic, ursolic and oleanolic acids, campestanol, cholesterol, campherol, ergosterol, lupeol, ?-sitosterol, sitostanol and santonin. These compounds were identified for the first time in this species collected from Benin. Among these compounds, ursolic acid (IC50 = 1.0±0.2 ?g/mL) and oleanolic acid (IC = 2.9±0.4 ?g/mL) showed very interesting antitrypanosomal activities with good selectivity on WI38 and J774 cells. These results explain in part, the antitrypanosomal activities of the O. gratissimum extracts.