Characterization of phenolic compounds by UHPLC-QTOF-MS/MS and functional properties of Syzygium malaccense leaves

Abstract Syzygium malaccense leaves are used in Brazilian folk medicine for its hypoglycemic and anti-inflammatory activities. In this context, the nutritional, chemical and biological characteristics were determined. The crude extract (E-CJ) of S malaccense leaves showed high nutritional parameters and was further purified yielding five fractions. The UHPLC-ESI-QTOF-MS/MS analysis of the acetone fraction (Fr-Ace) allowed identifying 23 compounds for the first time in S. malaccense leaves. Flavonoid derivatives were the most abundant group and mearnsetin, mearnsitrin, myricitrin, guaijaverin, afzelin, phlorizin, and phloretin were tentatively identified. The phenolics myricitrin (14.12 mg g−1), quercetin (0.88 mg g−1), catechin (0.84 mg g−1) and gallic acid (3.57 mg g−1) were quantified by HPLC-DAD-FL. The in vitro anti-inflammatory activity assay showed NF-κβ inhibition of 30 and 52% for E-CJ and Fr-Ace, respectively.