Stilbenoid profiling of grapevine cane extract and evaluation of their bioactivity on plants

Every year, more than a billion of tons of agricultural wastes is produced; these residues could be a priceless source of income since they still possess different high value compounds, such as polyphenols, well known for exerting benefits in humans and plants due to their biological properties (e.g., antioxidant, anti-microbial). Pruning canes are the major by-product of grapevine production. The extracts derived from this biomass contain several bioactives, among which we can find stilbenes and in particular resveratrol oligomers. The aim of our research is the optimization of convenient extractive methodologies for the production of polyphenol enriched extracts from grape pruning canes to be used as crop protective agents and biostimulants. For this purpose, different techniques (ASE, MW, EAE) and experimental parameters (solvents, temperature, pressure) have been evaluated and combined. The extracts were analysed by NMR spectroscopy to obtain a fingerprint of the crude, and the mass recovery was calculated. The most promising extracts were then further analysed by mass spectrometry and more than 40 different stilbenes (including dimers, trimers, and tetramers) were identified.