Recovery of phenolics from the ethanolic extract of sugarcane (Saccharum officinarum L.) baggase and evaluation of the antioxidant and antiproliferative activities

Abstract

In this work, recovery of phenolics from sugarcane bagasse was performed and total phenolic content, total flavonoid content and antioxidant activities were measured. Four fractions were yielded after extraction with various solvents and ethyl acetate fraction was performed into further purification, producing 30 sub-fractions (G1–G30). Six compounds were isolated and their structures were identified by high resolution mass spectrometry (HR-MS) and high definition nuclear magnetic resonance (HD-NMR) spectroscopy as p-coumaric acid, tricin, luteolin, tricin 7-O-β-glucopyranoside, protocatechuic acid and diosmetin 6-C-glucoside which was identified in this species for the first time. Tricin expressed highest antioxidant activity in ORAC assay (9.76±1.01μmol TE/μmol) but no antioxidant activity in PSC and CAA assays. The structure-activity relationship was discussed to elucidate the different activities of the isolated phenolics in ORAC and CAA assays. Luteolin, p-coumaric acid and protocatechuic acid showed antiproliferative effect against MCF-7 cells with the EC50 at 28.45, 1856.90 and 3670.56μM, respectively. This work reported the recovery of individual phenolics from bagasse, which suggested bagasse could be an abundant source of bioactive phenolics.