Identification of Potent Antitubercular Secondary Metabolites from Kigelia africana: An In‐Silico Investigation

Abstract Ethyl‐acetate extract of heartwood of Kigelia africana Lam . affords tecomaquinone‐I ( 1 ), lapachol ( 2 ), dehydro‐α‐lapachone ( 3 ), cluytyl ferulate ( 4 ), kigelinone ( 5 ), D‐sesamin ( 6 ), paulownin ( 7 ), wodeshiol ( 8 ) and cycloolivil ( 9 ). Isolation of cycloolivil from this plant is being reported for the first time. The structures of these compounds were elucidated by advanced spectroscopic methods ( 1 H, 13 C NMR, IR & Mass spectrometry). Structure of cycloolivil ( 9 ) was confirmed by X‐ray crystallographic analysis. In order to study the anti‐tubercular activity and to develop new drugs from natural sources, molecular docking studies of isolated phytochemicals were performed for potential inhibitory action towards Type I polyketide synthase 13 (Pks13). For this purpose, isoniazid, and a co‐crystallized PDB ligand were used as reference drug. Tecomaquinone‐I exhibited best docking score (−12.4 kcal/mol) among all the tested compounds. Molecular simulation and QSAR study of tecomaquinone‐I favoured docking results. Hence, the present study suggests that tecomaquinone‐I exhibits potent anti‐tubercular activity.