GC-MS Analysis and Antimicrobial Assessment of Syzygium cumini (L.) Skeels Seed Ethanol Extract

Abstract

People use plants to treat infections, and this has led to search of antimicrobials from medicinal plants. In this work, we evaluated the ethanol extract of Syzygium cumini seeds for their antibacterial and antifungal activities. Extraction was performed by maceration method using ethanol. The antimicrobial efficacy of the extract was assessed by agar well diffusion method against ten bacterial species, Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Serratia marcescens, Staphylococcus aureus and Streptococcus mutans, and five fungal species, Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Candida albicans and Mucor sp. Minimum inhibitory concentrations (MICs) of the extract were determined by resazurin microtiter plate assay.  Phytochemicals in the extract was identified by gas chromatography mass spectrometry (GC-MS) information.  In agar well diffusion method, Gram-negative bacteria such as P. aeruginosa and S. marcescens, Gram-positive bacteria such as B. subtilis and E. faecalis and fungi A. fumigatus were more susceptible showing larger zones of inhibition.  In resazurin method, low MICs were recorded for bacteria, B. cereus (<7.8 µg) and P. aeruginosa (15.6 µg) and fungi, A. fumigatus (31.2 µg).  Fifteen compounds were identified by GC-MS profiling of the extract.  The antimicrobial activity of the extract can be rightly related to the secondary metabolites in the ethanol extract of Syzygium cumini seeds.