Natural Products Catalog of Allsweet Watermelon Seeds and Evaluation of Their Novel Coumarins as Antimicrobial Candidates

The infections resistant to the current antimicrobials are becoming more prevalent today. So, in an attempt to discover the novel pharmacologically active scaffolding for the development of anti-microbial agents, five naturally simple coumarins were isolated from Allsweet watermelon seeds using four solvents (acetone, chloroform, dichloromethane, and ether). In this project, three extraction approaches were used as dynamic, microwave-, and ultrasonic-promoted maceration, and each one was achieved in three patterns, which were non-serial, as well as serial ascending-and descending-organized polarity. Relying on the phytochemical-screening data, only one of the 30 obtained extracts was picked to isolate the simple coumarin-based scaffolds. The chemical backbones of these isolates were depicted by comparing their spectral findings with those reported in the literature. The in vitro antimicrobial investigations were performed on the separated compounds using a broth dilution manner. This investigation was conducted against six pathogenic aerobic Gram-negative bacterial strains as well as a non-pathogenic one, using Ciprofloxacin as a control, four anaerobic bacterial strains utilizing Metronidazole as a control, and two fungal strains utilizing Nystatatin as a control. The results showed that the extracted simple coumarins have hopeful antimicrobial potential against the pathogens tested, with product RA4 outperforming the others. In addition, based on the PF values, the separated compounds revealed favorable bactericidal as well as fungicidal properties. According to these research findings, these advent natural, simple coumarins may serve as a useful scaffold for preparing novel anti-microbial medicines.