Pharmacokinetics, drug-likeness, antibacterial and antioxidant activity of secondary metabolites from the roots extracts of Crinum abyssinicum and Calotropis procera and in silico molecular docking study

Crinum abyssinicum and Calotropis procera were traditionally used for the treatment of different diseases such as hypertension, diabetes, hepatitis B, skin infection, anticancer, asthma, fever, and diarrhea. The structures of the compounds were characterized by 1H NMR, 13C NMR, and DEPT-135 spectra. Compounds 1-3 were reported herein for the first time from the species of C. abyssinicum. The DCM/MeOH (1:1) and MeOH roots extracts of C. abyssinicum showed significant inhibitory activity against S. aureus and P. aeruginosa with a mean inhibition zone of 16.67 ± 1.20 and 16.33 ± 0.33 mm, respectively. Compounds 4 and 5 showed promising activity against E. coli with a mean inhibition zone of 17.7  0.8 and 17.7  1.2 mm, respectively. The results of DPPH activity showed the DCM: MeOH (1:1) and MeOH roots extracts of C. abyssinicum inhibited the DPPH radical by 52.86  0.24 % and 45.6  0.11 %, respectively, whereas compound 5 displayed 85.7 % of inhibition. The drug-likeness analysis showed that compounds 2-4 satisfy Lipinski’s rule of five with zero violations. Compounds 2, and 6 showed binding affinities of −6.0, and −6.7 kcal/mol against E. coli DNA gyrase B, respectively, while 3 and 5 showed −5.0 and −5.0 kcal/mol, respectively against human peroxiredoxin 5. Therefore, the in vitro antibacterial, radical scavenging activity along with the molecular docking analysis suggest the potential use of the extracts of C. abyssinicum and compounds 2, 5, 6, and 3, 5 can be considered as promising antibacterial agents and free radical scavengers, respectively.