Antibacterial and antioxidant activities of a new phenolic coumpound from the roots barks of Cassia arereh Delile (Fabaceae)

Phytochemical study of the root barks of Cassia arereh resulted in the isolation of a new phenolic ester, 3′-hydroxy-4′-methoxystyrenyl-( E )- p -coumarate ( 1 ) isolated for the first time from natural source, alongside eight known compounds (2 – 9) . Compounds 1, 7 and 8 are depicted for the first time from Cassia genus. The structures of all compounds were established through NMR analysis (1D and 2D), High Resolution Mass Spectrometry (HRMS) and comparison with previously reported data in literature. Antioxidant activity was investigated through DPPH method while the antibacterial activity was done by the disc diffusion method on Escherichia coli and Salmonella typhimurium strains. Results showed that the methanol extract and compound 7 displayed significant (p < 0.01) DPPH radical scavenging activity which is comparable to BHT used as standard with IC 50 values of 118.04 and 122.24 µg/mL respectively. Otherwise, the same extract and compound 7 also showed significant antibacterial activity against S. typhi and E. coli with MIC values of 30 and 40 µg/mL, respectively. This research confirm the traditional use of Cassia arereh to treat ailments and provide supplementary data on its chemical profile and pharmacological potential.