Analysis of anticancer taxanes in hazelnuts (Corylus avellana L.) grown in Turkey

Taxol®, a taxane-derived substance was first obtained from Taxus brevifolia in 1971 as a result of the plant screening program initiated in the USA in 1960 for cancer treatment. Taxol® is used as a chemotherapy drug to stabilize microtubules in many types of cancer. As it is difficult to grow Taxus spp. and to use biotechnological methods such as cell culture in order to meet the need for taxol substances which are derivatives of taxane have been searched for in different plants. Turkey is the biggest hazelnut producer and exporter in the world. In this thesis, Çakıldak, Sivri, Tombul, Palaz, Kalınkara hazelnut varieties and Ham, Sivri Yağlı hazelnut genotypes were analysed in 5 different tissues of these hazelnut varieties and genotypes (green shells, hard shells, thin skins, thin skinned kernels and kernels) were examined in terms of their taxane types and their amount for the first time. Five tissues from each hazelnut varieties were extracted and the taxane derivetive components in the extracts were analysed both qualitatively and quantitatively with HPLC. Different quantities of taxane derivatives 10 deacetilybaccatin baccatin III and cephalomannine were identified in all hazelnuts. Paclitaxel was seen only in Ham, Palaz, Sivri ve Kalınkara hazelnuts. 10 deacetylbaccatin III was found in hard shell compared to all the other analysed hazelnut varieties and tissues mostly. Hazelnuts which included 10 deacetilybaccatin III with the highest amount were Ham (9,48 μg/g), Tombul (5,76 μg/g), Sivri (4,75 μg/g), Sivri Yağlı (4,26 μg/g), Kalınkara (2,72 μg/g), Çakıldak (2,26 μg/g) ve Palaz (2,12 μg/g) respectively. Baccatin III was found to have the highest amount of thin skins compared to other hazelnut tissues. The highest amount of hazelnut and baccatin III was detected in Tombul (10,44 μg/g), Kalınkara (7,53 μg/g), Ham (6,21 μg/g) ve Sivri Yağlı (4,65 μg/g) respectively. It was determined that the higher amount of cephalomanine was in thin skinned kernels and thin skins compared to other tissues of all hazelnuts. Cephalomanine was found mostly thin skins (6,37 μg/g) and thin skinned kernels (5,34 μg/g) of Sivri Yağlı, thin skinned kernels of Sivri (5,14 μg/g) and Palaz (4,74 μg/g), thin skins of Ham (4,31 μg/g) respectively. Paclitaxel, the raw material of Taxol®, which is widely used for cancer treatment in the world. It was found to be significantly higher in the tissues of 5 different hazelnut varieties and 2 genotypes analyzed for the first time in this thesis than the other tissues. The quantities of paclitaxel were analyzed by Palaz (3.37 μg / g), Ham (1.98 μg / g) and Kalınkara (1.80 μg / g), respectively. Another important result for paclitaxel analysis was that the amount of paclitaxel detected in the thin skinned kernel of the hazelnut (4.36 μg / g) was higher than the other tissues. These results showed that hazelnut (Corylus avellana L.) may be an alternative source of raw material for Taxol, which is the most common chemotherapy drug in the World. July 2019, 82 pages. Keywords: Hazelnut, Corylus avellana L., Taxane diterpenoid, HPLC, Anticancer.