Bioassay Guided Fractionation of N-hexane Extract of Salvia verbenaca (L.) Briq. ssp verbenaca Maire (S. clandestina Batt. non L) whole Plant from Morocco and Synthetic Molecules as Antileishmanial Agents

We have previously reported on the antileishmanial potential of S. clandestina from different solvents and reported that n-hexane extract exerted the strongest antileishmanial activity against Leishmania infantum. In this paper, we now report on the bioassay-guided fractionation of n-hexane extract, its effect on L. infantum, and their GC-MS analysis. Furthermore, four synthetic molecules derived from 6-nitro-1Hindazoles were synthesized and assessed for their antileishmanial activities. Six fractions resulting from the chromatographic separation of the n-hexane extract showed antileishmanial activity, with the highest activity reported for F3 (170 μg/mL). GC-MS analysis leads to the identification of several phytocompounds such as dihydro-ar-tumerone, and β-Tumerone in F1, 1,2-Benezenedicarboxylic acid, diethyl ester, and 1-Docosene, in F2, 2-Pentadecanone, 6, 10, 14-trimethyl-, 9, 12-Octadecadienoic acid (Z, Z)-, and 24(Z)-Methyl-25-homo-cholesterol in F3. M1 and M4 exhibited strong antileishmanial activity against L. infantum, L. tropica (IC50 = 5.53 μg/mL, IC50 = 248.72 μg/mL, IC50 = 102.93 μg/mL, and IC50 = 200 μg/mL, respectively). This indicates that S. clandestina is a promising source of antileishmanial effect for developing drugs with promising results and fewer side effects. Thus, further research is being done to isolate and identify the pure bioactive antileishmanial compounds.