Isolation of bioactive compounds of Clausena anisata (Willd.) Hook. growing in South Africa by liquid chromatography–mass spectroscopy profiling, and their antibacterial activities

Clausena anisata possesses several ethnopharmacological properties. It is used for the treatment of several diseases and health conditions, including oxidative stress and respiratory infections. This study was aimed at isolating and validating the potency of some bioactive compounds in this plant using Fourier transform infrared spectroscopy, liquid chromatography–mass spectroscopy and nuclear magnetic resonance techniques. A bioautography method was used for the antibacterial assay. Quercetin 3,4’-dimethyl ether was identified with a molecular mass of 330.2288 Da at a retention time of 0.72, clausine B was identified at a retention time of 24.31 and 24.37 with a molecular mass of 271.0844 Da, clausenocoumarine was identified at a retention time of 5.42 with a molecular weight of 366.1011 Da, while terpineol was also identified with the inhibition of the growth of the test organisms (Escherichia coli, Staphylococcus aureus and Subtilis cereus) to quercetin 3,4’-dimethyl ether, clausine B and clausenocoumarin observed at Rf values of 0.24, 0.52 and 0.54, respectively, on the plate using hexane/ethyl acetate (2:1) as mobile phase. A novel enantiomer of anisocoumarin derivatives and three known compounds were isolated and identified from a fraction showing a single band in the acetone leaf extract of C. anisata. Their chemical compounds were elucidated by nuclear magnetic resonance. The pharmacological potency of these compounds was discussed.