Antileishmanial and pharmacophore modeling of abietane-type diterpenoids extracted from the roots of Salvia hydrangea.

• Four abietane-type diterpenoids were isolated and identified from roots of Salvia hydrangea. • Antileishmanial activity of purified compounds was tested against the promastigotes of leishmania major. • The cytotoxicity of the plant's root extract was assessed against two human cancer cell lines, MCF-7 and MOLT-4. • A pharmacophore modeling study for antileishmanial activity was carried out. Four abietane diterpenoids, agastanol, (1), 6, 7-dehydroroyleanone (2), 7 α -acetoxyroyleanone (3), and ferruginol (4) were isolated from root extract of Salvia hydrangea. The chemical structures of compounds were identified using EI-MS, ESI-MS, 1D, and 2D NMR spectroscopic analyses. Antileishmanial activity of 1 – 4 was tested against the promastigotes of Leishmania major using in vitro antiparasitic activity assay. Compound 4 (IC 50 = 12.1 ± 2.1 µg/mL) showed considerable antileishmanial activity. The root extract showed significant cytotoxicity against two cancer cell lines including, MCF-7 (IC 50 = 7.0 ± 2.0 µg/mL), and, MOLT-4 (IC 50 = 2.8 ± 0.7 µg/mL) using the MTT bioassay. A pharmacophore modeling study for antileishmanial activity was carried out to render essential features for an effective inhibition. The model has 7 features, including 1 hydrogen bond acceptor, 1 aromatic, and 5 hydrophobic features. In conclusion, the roots of S. hydrangea are presented as the potential source for further investigation of antileishmanial and cytotoxic compounds. Image, graphical abstract [ABSTRACT FROM AUTHOR]