Abstract
Rhodomyrtus tomentosa fruits, endemic to the Western Ghats were analyzed for its free, bound and esterified phenolics by Ultra High Performance Liquid Chromatography-Mass Spectrometry. Overall, twenty-nine phenolic compounds were identified, amongst them 18 were detected in this fruit for the first time. Gallic acid (80.44 ± 8.74 mg/100 g) and ellagic acid (107.47 ± 7.28 mg/100 g) were the most prominent ones found in the bound phenolic fraction and gallic acid (103.76 ± 6.34 mg/100 g) in the esterified phenolic fraction of the fruit, respectively. Total Phenolic content was found to be highest in bound phenolics (7.09 ± 0.17 mg Gallic acid equivalent/g). The antioxidant and antimicrobial activities of the three extracts namely free, bound and esterified phenolic fruit fractions have been analyzed. Bound phenolics exhibited the highest antioxidant potential (DPPH-15.63 ± 0.86; ABTS-34.73 ± 0.07; FRAP-17.89 ± 0.27 mg/g Ascorbic acid equivalent). The bound phenolics showed good antimicrobial activity against Bacillus cereus, Staphylococcus aureus and Escherichia coli with a MIC of 0.156, 0.625 and 1.25 mg/mL respectively. The exploration of phenolic compounds in Indian variety of Rhodomyrtus tomentosa fruits may provide useful insights on its utilization as a functional food ingredient.