Isolation of Hesperidin from Orange Peels and Synthesis of Its Semi-Synthetic Derivatives

The flavonoids found in the petals of many flowers are attracting the attention of researchers in different disciplines with their structural diversity, biological and ecological importance, healing effects and anticancer activities. The binding of different groups such as hydroxyl, methoxy, methyl, isoprenil and benzyl to the fifteen carbon flavonoid skeleton makes theoretically possible for a large number of different flavonoid structures. The most well-known flavonoids are anthocyanidins found in blueberries, hesperidin in turgans, flavan-3-ols in black tea. Hesperidine and aglyconin, which are found in large amounts in citrus fruits (Rutaceae), show a wide range of biopharmaceutical activity such as anti-cancer, anti-inflammatory, antioxidant and anti-tumor. Our country, which is at the forefront of citrus production, exports the orange shells rich in hesperidin mainly in Germany, France and imports processed precious chemicals-hesperidin, hesperetin and their derivatives. This imported hesperidin, hesperetin and its derivatives are used as active ingredients of drugs sold as circulation regulators in our country's pharmaceutical market such as Daflon® and Vendios®. In this thesis, the extraction of hesperidine was obtained as a result of the extraction of orange peels from orange grown in our country under different conditions.After finding the optimum extraction conditions, hesperidin reach extract was purified by acidic precipitation in order to obtain hesperidin. Hesperetin, that is an aglycone of hesperidin was obtained after acidic hydrolysis of hesperidin in different conditions such as acid type, temperature, duration, etc. once hesperetin was obtained both hesperidin and hesperetin were converted into their alpha beta unsaturated derivatives, diosmin and diosmetin respectively, by elimination reaction. Then, semi-synthetic derivatives of these compounds i.e. Wittig reaction, fully and partly methylation were performed. All the synthesized and obtained compounds were purified and then their structural identifications were performed by spectroscopic techniques such as 1H- NMR, 13C-NMR and FT-IR.