Extraction and UPLC-MS-MS identification of active ingredients of Henophyton deserti: Antibacterial, antifungal and...

The plant extracts are gaining importance as natural antibiotic agents in this time of increasing antibiotic resistance. Therefore, the active ingredients of the Henophyton deserti plant were extracted and identified by UPLC-MS-MS analysis. The major constituents analyzed by UPLC-MS-MS were (-) catechin, curcumin, ferulic acid, quercetin-3-glucoside, resveratrol, and rutin, with different concentrations in various extracting solvents. The active ingredients were eluted from 1.60 to 10.11 min. The plant extract showed strong activity and efficacy against Gram-positive bacterial strains and the Candida albicans fungus. The MIC and MBC values were in the range of 0.78 to 12.5 and 1.56 to 50.0 mg/mL. The ratio of MBC and MIC was about 4.0 for both bacteria and fungi. The mechanism of antimicrobial activities was determined by modelling in silico studies of the identified molecules with dihydrofolate reductase (DHFR), isoleucyl-t-RNA synthetase (LeuRS), and sterol 14α-demethylase (CYP51). The molecular docking analyses found that rutin and quercetin-3-glucoside were stable at the DHFR active site, with binding energies of -8.9 and - 8.5 kcal/mol. The curcumin, rutin, and quercetin-3-glucoside were stable with LeuRS, with binding energies of -8.4, -9.2, and - 8.7 kcal/mol. For CYP51, curcumin, rutin, and quercetin-3-glucoside showed stability with binding energies of -9.1, -8.1, and - 8.4 kcal/mol. The molecular dynamics simulations results indicated that quercetin-3-glucoside had the highest stability at the DHFR active site and with LeuRS, while curcumin was a strong candidate for inhibiting CYP51. Briefly, the plant extract may be considered a promising candidate for developing new antibiotics.