Corylus avellana as source of antioxidant diarylheptanoids

Hazelnut (Corylus avellana L.), belonging to the family Betulaceae, is one of the most popular tree nuts [1]. Among Italian cultivars, ‘Tonda di Giffoni’ and ‘Tonda Gentile delle Langhe’ gained the European Protected Geographical Indication (PGI) label for their processing quality, which guarantees the origin, the typical features, the high physico-chemical quality and the organoleptic properties [2].

In the frame of a research programme aimed at exploiting C. avellana biomasses as source of bioactive compounds, cyclic diarylheptanoids and diaryletherheptanoids named giffonins A-V have been isolated from leaves, leafy covers, male flowers and seeds of C. avellana, cultivar ‘Tonda di Giffoni’ [1]-[5]. Diarylheptanoids are a class of natural products based on the 1,7-diphenylheptane skeleton. The most representative compound belonging to this class is the well known curcumin, possessing various biological activities, including antioxidant, cancer-preventing, anti-inflammatory [4]. The isolated compounds have been evaluated in different models showing that, as for curcumin, some isolated giffonins were able to prevent oxidative damages of human plasma lipids, induced by H₂O₂ and H₂O₂/Fe²⁺.

Our work has been extended to the leaves and seeds of the cultivar ‘Tonda Gentile delle Langhe’ explored by analytical approaches based on LC-HRMS/MS and NMR. In the phenolic profiles the occurrence of cyclic diarylheptanoids corresponding to giffonins or to closely related compounds along with linear diarylheptanoids has been highlighted, confirming C. avellana leaves as a rich source of antioxidant diarylheptanoids.

Fig. 1

• References

• 1 Masullo M, Cerulli A, Olas B, Pizza C, Piacente S. Giffonins A-I, antioxidant cyclized diarylheptanoids from the leaves of the hazelnut tree (Corylus avellana), Source of the Italian PGI Product “Nocciola di Giffoni”. J Nat Prod 2015; 78: 17-25.
• 2 Masullo M, Cerulli A, Mari A, CCdS Santos, Pizza C, Piacente S. LC-MS profiling highlights hazelnut (Nocciola di Giffoni PGI) shells as a byproduct rich in antioxidant phenolics. Food Res Int 2017; 101: 180-187.
• 3 Cerulli A, Lauro G, Masullo M, Cantone V, Olas B, Kontek B, Nazzaro F, Bifulco G, Piacente S. Cyclic Diarylheptanoids from Corylus avellana Green Leafy Covers: Determination of Their Absolute Configurations and Evaluation of Their Antioxidant and Antimicrobial Activities. J Nat Prod 2017; 80: 1703-1713.
• 4 Masullo M, Cantone V, Cerulli A, Lauro G, Messano F, Russo GL, Pizza C, Bifulco G, Piacente S. Giffonins J-P, highly hydroxylated cyclized diarylheptanoids from the leaves of Corylus avellana cultivar “Tonda di Giffoni”. J Nat Prod 2015; 78: 2975-2982.
• 5 Masullo M, Mari A, Cerulli A, Bottone A, Kontek B, Olas B, Pizza C, Piacente S. Quali-quantitative analysis of the phenolic fraction of the flowers of Corylus avellana, source of the Italian PGI product “Nocciola di Giffoni”: Isolation of antioxidant diarylheptanoids. Phytochemistry 2016; 130: 273-281.