Grape Canes from Typical Cultivars of Campania (Southern Italy) as a Source of High-Value Bioactive Compounds: Phenolic Profile, Antioxidant and Antimicrobial Activities.

The purpose of the current study was to determine the phenolic composition, antioxidant,and antimicrobial activities in grape cane extracts from typical cultivars of Southern Italy. Aqueousextracts at different pHs (1-13) were prepared from "Aglianico", "Fiano", and "Greco" grape canes.The results demonstrated that an alkaline pH (13.00) produced the best polyphenol-rich extracts, asthe total phenolic content was more than double when compared to the respective extracts preparedat pH 1.00. "Greco" grape canes gave the highest quantity of phenolic compounds at each pH,ranging from 42.7 0.4 to 104.3 3.0 mg Gallic Acid Equivalents (GAE)/g Dry Extract (DE) frompH 1.00 to 13.00. The Radical Scavenging Activity (RSA) and the Ferric Reducing Antioxidant Power(FRAP) were measured. The highest antioxidant activity was showed by "Greco" extract at pH 7.00.Seventy-five compounds were identified in the extracts by HPLC-MS with six of them described forthe first time in grape canes. Procyanidins were highly abundant in extracts at pH 7.00, whereasstilbenoids were the most represented compounds at pH 13.00. Very strong antiviral activity againstherpes simplex viruses was recorded for the extracts at pH 7.00 and 13.00 that were active in theearly stages of infection by acting directly against the viral particles. The overall results suggest thatgrape canes, currently underutilized, can be usefully valorised by providing active extracts to use asantioxidant and antiviral agents.