qNMR quantification of phenolic compounds in dry extract of Myrcia multiflora leaves and its antioxidant, anti-AGE, and enzymatic inhibition activities

[Display omitted] •Phenolic compounds were identified by HRMS and NMR from Myrcia multiflora leaves.•Six phenolic compounds were quantified by qHNMR in M. multiflora leaves extract.•The method’s effectiveness for extracting constituents was evaluated by qHNMR.•The dry extract from Myrcia multiflora leaves inhibits the enzyme α-glucosidase.•Antioxidant, anti-AGE, and cytotoxicity activities of the dry extract are shown. Myrcia multiflora (Lam.) DC. is often used in Brazilian folk medicine to control diabetes. Analysis using HPLC-HRMS and NMR of the dry extract from the infusion of leaves of this species revealed twelve phenolic compounds. Among these compounds, chlorogenic acid (1), 4-O-caffeoylquinic acid (2), corilagin (3), chebulagic acid (4), pedunculagin (5), quercetin-3-O-β-2″-galloylglucoside (7), and kaempferol-3-O-rhamnoside (12) are described for the first time in this matrix. Furthermore, six compounds were quantified using qNMR. The compounds in the dry extracts are 3, 6 (myricetin-3-O-d-glucoside), 8 (myricitrin), 9 (hyperoside), 10 (guaijaverin) and 11 (quercitrin). These compounds may be considered chemical markers in this matrix. In addition, this extract presents activities of α-glucosidase inhibition (IC50 = 79.9 μg mL−1) and glycation in vitro (IC50 = 10.2 μg mL−1), in addition to antioxidant activity against DPPH and ABTS radicals (1,856.7 and 1,032.0 μmol TEq, respectively). This extract did not show significant cytotoxicity in human fibroblasts. Therefore, the enzymatic inhibition, anti-AGE (advanced glycation end-products) and antioxidant activities of Myrcia multiflora leaves corroborated its antidiabetic therapeutic potential and instigates future preclinical studies aimed at the treatment of diabetes mellitus and its complications.