Analysis of Lipophilic Compounds from Corylus avellana Leaves

Abstract

Hazelnut (Corylus avellana L.) is a bush of the family Betulaceae. Its nuts are widely used in the food industry [1]. Folk medicine recommends internal use of the nuts as a lactogenic, antiparasitic, and anti-atherosclerotic agent; external use, for treating burns [2]. According to the literature, hazelnuts contain paclitaxel, which exhibits antitumor activity [3]. Leaves and bark of C. avellana are also used in folk medicine. The leaf decoction is used to treat thrombophlebitis, varicose veins, and trophic lower-leg ulcers [2, 4]. Portuguese researchers proved that preparations from hazelnut leaves were effective as antimicrobial agents and antioxidants [5]. The goal of our research was to determine the most significant lipophilic compounds in C. avellana leaves collected in various regions of Ukraine. Lipophilic compounds were analyzed by GC-MS [6] using the previously developed procedure [7]. Dried and powdered leaves were extracted with CH2Cl2 (raw material:extractant ratio 1:20). Tridecane was added as an internal standard to give 50 g calculated for a certain amount of plant sample. We used an Agilent Technologies Series 6890 chromatograph with an Agilent DB-5 MS (5% phenyl) capillary chromatography column (30 m 0.25 mm) and a Series 5973 mass spectrometer. The temperature was thermostatted from 50°C (1 min) to 320°C at 4°C/min and then was held at the final temperature for 9 min. The carrier gas was He at flow rate 1.2 mL/min. Compounds were identified using NIST 05 and Wiley 138 massspectra libraries. The investigation detected 44 lipophilic compounds in C. avellana leaves. Of these, 41 were identified and quantified. They included organic acids, hydrocarbons, terpenes, alcohols, aldehydes, and phytosterols. Table 1 presents the results for the contents of the principal lipophilic compounds (>0.1% of the total peak area). The fatty-acids in C. avellana leaves were dominated by palmitic acid. The presence of hexenoic acid in the studied raw material was interesting from a scientific point of view because its structure is similar to that of GABA and its amides are included in anticonvulsive drugs. Furthermore, rather high contents of phytosterols ( -sitosterol), aldehydes (phenylacetaldehyde, trans-2-hexenal), and hydrocarbons (neophytadiene) were noted in the studied raw materials. Thus, C. avellana leaves were a promising raw material for the further study and discovery of several biologically active compounds and also for the development of original phytotherapeutic drugs based on them.