Bioassay-Guided Fractionation with Antimalarial and Antimicrobial Activities of Paeonia officinalis

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).