UPLC/ Tandem mass and antimicrobial activity of Khaya senegalensis (A.Juss.

Characterization of flavonoids and limonoids in the defatted acetone extract of Khaya senegalensis flowers (A. Juss.) contents was performed using ultra performance liquid chromatography (UPLC) coupled with ultraviolet (UV) and electrospray ionization (ESI) mass spectrometry, furthermore, tandem mass spectrometry (MS/MS) was performed to assist in the structural elucidation. The antimicrobial effect was tested against representative gram positive and negative bacteria and candida. Cytotoxicity of extract was evaluated using the mitochondrial-dependent reduction of MTT. The method used enabled identification of five flavonoid glycosides (di and mono-sugar) and twelve limonoids of different types viz : mexicanolides, phragmalins and angolensate were tentatively identified. The extract was effective against tested microorganism revealing potent growth  inhibitory effect on Salmonella typhimurium ATCC 25566, Escherichia coli NRRN 3008 , Pseudomonas aeruginosa ATCC 10145 and fungus Candida albicans EMCC105, MIC  ≤ 25μg/μl  while MIC ≤ 50 μg/μl for Bacillus cereus , staphylococcus aureus ATCC 6538.Extract showed cytotoxicity against MCF7 (Breast carcinoma cell line) compared to doxorubicin, IC 50 =88.1(μg/mL) but no activity on HCT 116 (Colon carcinoma cell line) and HepG2 (liver cell carcinoma) was observed. Bioactive  compounds in K senegalensis  flowers acetone extract  possesses promising antimicrobial activity with low cytotoxic effect warrants  further investigation for their therapeutic and prophylactic roles.