Phytochemical screening and biological properties of Quintral flower polyphenolic fractions

<i>Tristerix corymbosus</i> flower is used in traditional medicine for its antioxidant and antibacterial properties, which are attributed to phenolic compounds. These compounds present different grades of associations with the plant matrix (free, esterified, and insoluble). This study aimed to determine which fraction contributes the most to total phenolic and flavonoid contents and bioactive properties. The total phenolic content was higher in the free fraction. In contrast, the esterified fraction exhibited the highest total flavonoid content and the greatest number of characterised compounds (chlorogenic, coumaric, and sinapic acids). All fractions exhibited antioxidant capacity against FRAP, DPPH, and ABTS assays. The free and esterified fractions presented antibacterial capacity against <i>E. coli, S. typhi</i>, and <i>S. aureus</i>. Chlorogenic and sinapic acids were correlated with the antibacterial capacity against <i>E. coli</i> and <i>S. typhi.</i> While coumaric acid correlated with the antibacterial capacity against <i>S. aureus</i>. These findings enable the exploration of potential applications for the different fractions.