Coumarins from Red Delicious Apple Seeds: Extraction, Phytochemical Analysis, and Evaluation as Antimicrobial Agents

Abstract

Eman Tareq Mohammed, Yasser Fakri Mustafa.

The evolution of resistance to many valid antimicrobial agents and the demand for exploring novel agents to deal with this emerge are well-highlighted. In this report, the seeds of Red Delicious apples were extracted by four solvents; n-hexane, chloroform, methanol and water. This was carried out using three methods, which are kinetic maceration, ultrasound- and microwaves- expedited extraction techniques. These methods were performed in three modes including non-serial, serial rising- and falling- arranged in polarity. Phytochemical study indicated the presence of coumarins in the methanol and chloroform extracts obtained from the applied methods and modes. Four novel furanocoumarins were isolated and their chemical structures characterized by corresponding their spectroscopic data with those detected in literature. Two in vitro antimicrobial studies were verified for the isolated products via a broth dilution method; the antibacterial activity versus the following standard strains: Pseudomonas aeruginosa, Klebsiella pneumonia, Haemophilus influenzae and Escherichia coli utilizing Ciprofloxacin as a reference, and the antifungal activity versus the following standard strains: Candida albicans and Aspergillus niger using Nystatin as a reference. The results indicated that the isolated furanocoumarins have a promising antimicrobial activity against the test microorganisms with superiority attributed to compound R1. Also, the isolated products showed encouraging bactericidal and fungicidal activities according to the values of MBC/MIC and MFC/MIC ratios. It is concluded that these novel furanocoumarins may provide a convenient scaffold for the development of new antimicrobial agents.