Bioassay-guided fractionation technique of roots of Paeonia officinalis led to isolation and structure elucidation of seven known compounds, including four monoterpene glycosides: lactiflorin (1), paeoniflorin (4), galloyl paeoniflorin (5), and (Z)-(1S,5R)-β-pinen-10-yl β-vicianoside (7); two phenolics: benzoic acid (2) and methyl gallate (3); and one sterol glycoside: β-sitosterol 3-O-β-D-glucopyranoside (6). The different fractions and the isolated compounds were evaluated for their antimicrobial and antimalarial activities. Fraction II and III showed antifungal activity against Candida neoformans with IC50 values of 28.11 and 74.37 µg/mL, respectively, compared with the standard fluconazole (IC50 = 4.68 µg/mL), and antibacterial potential against Pseudomonas aeruginosa (IC50 = 20.27 and 24.82 µg/mL, respectively) and Klebsiella pneumoniae (IC50 = 43.21 and 94.4 µg/mL, respectively), compared with the standard meropenem (IC50 = 28.67 and 43.94 µg/mL, respectively). Compounds 3 and 5 showed antimalarial activity against Plasmodium falciparum D6 with IC50 values of 1.57 and 4.72 µg/mL and P. falciparum W2 with IC50 values of 0.61 and 2.91 µg/mL, respectively, compared with the standard chloroquine (IC50 = 0.026 and 0.14 µg/mL, respectively).
Keywords: Paeonia officinalis; antimalarial; antimicrobial; phytoconstituents.