Novel coumarins isolated from the seeds of Citrullus lanatus as potential antimicrobial agents

In this study, four different solvents were utilized (acetone, chloroform, dichloromethane, and ether), with three extraction approaches as motion, ultrasonic bath-, and microwave oven-fostered maceration and also, this was performed in three modalities: non-serial, serial ascending-, and descending-design polarity. Among the thirty extracts resulting from the mentioned approaches and modalities, only an ether extract from the descending design polarity was chosen to extract our novel coumarins. This choice is based on the phytochemical examination performed. Extracted coumarins’ structure identification was achieved via gathering and interpretation of the spectral data to those found in the chemical guide. The isolated chemicals’ antimicrobial potential was assessed in vitro via broth-micro dilution technology. The targeted pathogen strains were: six strains of standard pathogenic aerobic gram negative bacteria, four strains of anaerobic bacteria, as well as two strains of fungi. In addition to one strain that is a nonpathogenic intestinal flora. In this assessment, the references used were Ciprofloxacin, Metronidazole, and Nystatin for the aerobic G-, anaerobic, and fungi, respectively. The five novel isolates all indicated antimicrobial potential, but RA4 still exceeded the others. All the tested chemicals exhibited bactericidal and fungicidal potential against all the tested strains of pathogenic bacteria and fungi, based upon PF readings of more than four. On the other hand, RA4 and RA2 were the only two that revealed bacteriostatic effects on the normal flora. Finally, this study concluded the possibility of utilizing these isolated compounds as a source for creating novel antimicrobials.