Two new 30-norfriedelane triterpenes from Caloncoba glauca (P. Beauv.) Gilg (Achariaceae)

Tamba, Charlemagne Ndoumbe; Tsopgni, Willifred Dongmo Tekapi; Fotso, Bernard Samuel Hodjie; Ekon, Jean Pierre Longue; Nsangou, Mohamed Foundikou; Nyobe, Judith Caroline Ngo; Sewald, Norbert; Ndom, Jean Claude

doi:10.6084/m9.figshare.23998339.v1

Two new 30-norfriedelane triterpenes from Caloncoba glauca (P. Beauv.) Gilg (Achariaceae)

journal contribution

posted on 2023-08-21, 11:00 authored by Charlemagne Ndoumbe Tamba, Willifred Dongmo Tekapi Tsopgni, Bernard Samuel Hodjie Fotso, Jean Pierre Longue Ekon, Mohamed Foundikou Nsangou, Judith Caroline Ngo Nyobe, Norbert Sewald, Jean Claude Ndom

The chemical investigation of the methanolic root extract of Caloncoba glauca (P. Beauv.) Gilg exhibited two new 30-norfriedelane triterpenes, glaucalactones A and B (1–2), together with eight known compounds, caloncobalactone (3), friedelin (4), friedelanol (5), 3-oxo-friedelan-28-oic acid (6), stigmasterol (7), β-sitosterol (8), β-sitosterol-3-O-β-D-glucopyranoside (9) and pentacosanoic acid (10). The structures of the isolates were elucidated by extensive spectroscopic and spectrometric analyses (1D and 2D NMR, ESI-MS) and by comparison with previously reported data. All the compounds were tested for their antioxidant, antifungal and antibacterial activities. Compound 1 displayed weak antibacterial effect with MIC value of 125 μg/mL against Staphylococcus aureus and Escherishia coli. Compound 6 exhibited moderated antifungal activity against Candida krusei with MIC value of 62.5 μg/mL. All the isolates were found to be inactive as antioxidants in the DPPH, ABTS and FRAP assays.