Title : Phytochemical investigation and antibacterial evaluation of Musanga Cecropioides: First report of sterols and triterpenoids from stem bark extracts
Abstract:
Musanga cecropioides, commonly known as African corkwood, was studied for its phytochemical composition and antibacterial properties. Stem bark extracts were prepared using a dichloromethane-methanol mixture and subjected to chromatographic techniques, including column chromatography and thin-layer chromatography for compound isolation. Six known bioactive compounds were successfully isolated and identified: three sterols, stigmasterol (1), cupreol (2), and daucosterol (3), and three pentacyclic triterpenoids, friedelin (4), oleanolic acid (5), and betulinic acid (6). Structural elucidation was accomplished through spectroscopic analysis using one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR), Fourier-transform infrared (FTIR) spectroscopy, and high-resolution electrospray ionization mass spectrometry (HRESIMS). Spectral data were cross-referenced with literature reports to confirm compound identities. The antibacterial efficacy of the isolated compounds and crude extract was assessed using the microdilution method against twelve bacterial strains. Among these, Bacillus subtilis and Klebsiella aerogenes were the most susceptible. Most isolated compounds exhibited minimum inhibitory concentrations (MICs) of 18.5 µg/mL against these bacterial strains. However, friedelin (4) was significantly less active, with an MIC of 294 µg/mL against Klebsiella aerogenes. Of particular note, oleanolic acid (5) displayed the highest antibacterial potency, outperforming three standard antibiotics in activity against certain bacterial strains. This study provides new insights into the chemical constituents of Musanga cecropioides, marking the first report of stigmasterol, cupreol, daucosterol, friedelin, and betulinic acid being isolated from this species. The findings highlight the considerable antibacterial potential of these natural compounds, positioning Musanga cecropioides as a promising source for novel antibacterial agents. Further research may explore its therapeutic applications and contribute to the development of plant-derived antimicrobials.
