Determination of total proanthocyanidins in hazel (Corylus Avellana L.) leaves during vegetation period

Introduction: Hazel (Corylus Avellana L.) belongs to the Betulaceae family and is a common plant in Europe and Asia. Previous studies have shown that proanthocyanidins, which belong to the class of flavonoids, are one of the main chemical components found in Corylus Avellana L. leaves [2,3]. Proanthocyanidins are important for their strong antioxidant properties and have been shown to have anti-inflammatory, cardioprotective, antithrombotic, anti-asthmatic, antimicrobial effect [1,4]. The aim of this study is to determine the amount of proanthocyanidins in hazel leaves during vegetation period. Materials and methods: Leaf samples were collected from natural habitats in Lithuania (Prienai, Kaunas) during vegetation period. The determination of total proanthocyanidins was determinated with UV-VIS spectrophotometry using the p-DMCA reagent and expressed in equivalent of epicatechin (EE). Results: Total proanthocyanidins amount in hazel leaves varies from 2.32±0.69 mg/g in Prienai region to 22.96±1.80 mg/g in Kaunas region. The highest content of total proanthocyanidins compounds was determined in Kaunas region during full leaf expansion and in Prienai region during leaf maturation and leaf senescence. Conclusions: The greatest amount of proanthocyanidins was established in Corylus avellana L. leaves collected in Kaunas region during full leaf expansion in July.