PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

The papaya plant yields a lot of by-products after its fruit is harvested. Papaya leaves contain a bio-active phytochemical that can serve as a potential source of natural antibacterial agents. Phytochemical screening has discovered that papaya leaf extract contains compounds such as alkaloids, tannins and saponins. Crude alkaloid detection by Dragendorff's test was positive. Chemical structure characterisation of extracted crude alkaloids revealed by ¹H-NMR spectrum testing was partial, as the spectrum identified only the chemical structure corresponding to aliphatic carbon compounds. Crude alkaloid dissolved in organic solvent dichloromethane showed no antifungal properties towards Candida albicans. Antibacterial properties of crude alkaloid dissolved in dichloromethane were selective on both Gram positive and negative bacteria. Kirby Bauer test results showed negative inhibition for both Staphylococcus aureus (Gram positive) and Salmonella typhi (Gram negative) but inhibition was positive for antibiotic resistant bacteria, MRSA (Gram positive) and Escherichia coli (Gram negative) bacteria. Inhibition efficacy increased with the amount of crude alkaloids used. The present study supports the use of papaya by-products as an alternative natural antibiotic for both the community and healthcare personnel.