Chemical investigation of the petroleum ether extract of heartwood of Tecomella undulata led to the isolation of tectonaquinone B (1), 2-methylquinizarin (2) along with tecomaquinone I (3), lapachol (4), 2-isopropenylnaphtho[2,3-b]-furan-4,9-quinone (5), dehydro-α-lapachone (6), α-lapachone (7), and β-lapachone (8). This is the first report of isolation of tectonaquinone B and 2-methylquinizarin from this plant. The structures of compounds were elucidated by advanced spectroscopic methods. Molecular docking study for potential inhibitory action toward CDK7 (cyclin-dependent kinase 7) were performed, which proved that these compounds have high binding affinities with the receptor protein (CDK7). 2-Methylquinizarin exhibited best docking score (-7.70 kcal/mol) among all the tested compounds. The present study showed that 2-methylquinizarin may exhibit potent anticancer activity through inhibiting CDK7 via interaction with Met94.
Keywords: CDK7; Tecomella undulata; bignoniaceae; docking; extraction; isolation.