NMR-based phytochemical analysis of Vitis vinifera cv Falanghina leaves. Characterization of a previously undescribed biflavonoid with antiproliferative activity

Vitis vinifera cv Falanghina is an ancient grape variety of Southern Italy. A thorough phytochemical analysis of the Falanghina leaves was conducted to investigate its specialised metabolite content. Along with already known molecules, such as caftaric acid, quercetin-3-O-β-D-glucopyranoside, quercetin-3-O-β-D-glucuronide, kaempferol- 3-O-β-D-glucopyranoside and kaempferol-3-O-β-D-glucuronide, a previously undescribed biflavonoid was identified. For this last compound, a moderate bioactivity against metastatic melanoma cells proliferation was discovered. This datum can be of some interest to researchers studying human melanoma. The high content in antioxidant glycosylated flavonoids supports the exploitation of grape vine leaves as an inexpensive source of natural products for the food industry and for both pharmaceutical and nutraceutical companies. Additionally, this study offers important insights into the plant physiology, thus prompting possible technological researches of genetic selection based on the vine adaptation to specific pedo-climatic environments.