Constituents of the Stem Bark of Symphonia globulifera Linn. f. with Antileishmanial and Antibacterial Activities

Abstract

The chemical investigation of the n-hexane fraction from the methanol extract of the stem bark of Symphonia globulifera Linn f., which displayed good in vitro activity against Leishmania donovani NR-48822 promastigotes (IC50 43.11 µg/mL), led to the isolation of three previously unreported polyprenylated benzophenones, guttiferone U (1), V (2)/W (3), and a new tocotrienol derivative named globuliferanol (4), along with 11 known compounds (5–15). Their structures were elucidated based on their NMR and MS data. Some isolated compounds were assessed for both their antileishmanial and cytotoxic activities against L. donovani and Vero cells, respectively. Guttiferone K (5) exhibited the best potency (IC50 3.30 μg/mL), but with low selectivity to Vero cells. The n-hexane fraction and some compounds were also assessed in vitro for their antibacterial activity against seven bacterial strains. All the samples exhibited moderate to potent antibacterial activity (MICs ≤ 15.6 µg/mL) against at least one of the tested strains.

Polyoxygenated Stigmastane-Type Steroids from Vernonia kotschyana Sch. Bip. ex Walp. and Their Chemophenetic Significance

“…The antibacterial assay was performed on five bacteria strains including four standards ( Escherichia coli ATCC25322, Staphylococcus aureus ATCC25923, Staphylococcus pneumoniae ATCC461916, and Pseudomonas aeruginosa HM801) and the clinical Klebsiella pneumonia CPC. They were maintained on fresh Mueller Hinton Agar (MHA) for 24 h prior to any antibacterial assay, and the minimal inhibitory concentrations (MICs) of the tested samples were determined as reported previously [ 33 ].…”