Relationship Between Bioactive Compounds and Biological Activities (Antioxidant, Antimicrobial, Antihaemolytic) of...

The genus Miconia is used in traditional medicine, but there are few studies supporting the bioactive potential of Miconia crocea. This study aimed to evaluate the physicochemical properties, bioactive compound content, and antioxidant, antimicrobial and antihaemolytic activities at four different phenological stages of M. crocea. The pH, soluble solids, titratable acidity, moisture and ash content were determined. Mineral contents were determined by atomic absorption. Vitamin C, organic acids, carotenoids, chlorophylls and derivatives and phenols were determined by chromatography. Total anthocyanins were determined by spectrophotometry. The antioxidant capacity was evaluated using ABTS and DPPH assays, and the antimicrobial activity was tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus mutans, Candida albicans and Candida tropicalis. Potassium was the predominant mineral (>1000 mg/100 g DW), while malic acid was the predominant organic acid. Lutein was the most abundant carotenoid, as among the phenolic compounds, m-coumaric acid and chlorogenic acid were most abundant (>1000 mg/100 g DW). The optimal method for preparing the extract for antimicrobial and haemolytic activity, with a focus on phenols, involved using 50% ethanol, applying ultrasound for six minutes, and carrying out three extractions. The M0% extract exhibited the most potent antimicrobial activity against S. mutans (MIC: 7.8 mg/mL). Anti-haemolytic activity indicates biocompatibility. The results emphasise the bioactive and antimicrobial potential of M. crocea, suggesting its possible application in various industries. However, further research is needed in the form of in vivo studies.