Isolation and structure elucidation of the bioactive secondary metabolites from endemic polygonum sivasicum kit tan & yildiz

48 genera and 1200 species worldwide represent the Polygonace family. Our country is home to 10 genera that belong to this family. The genus Polygonum includes 40 species, making it the biggest member of this family in Turkey. Polygonum sivasicum Kit tan & Yıldız, which is one of the 7 endemic Polygonum species, grows naturally in Sivas at 1700 m altitude. The purpose of this thesis is to isolate the bioactive secondary metabolites from P. sivasicum and elucidate their chemical structures. Aerial parts of the plant were collected and dried under optimum conditions. The ground plant material was macerated with hexane, ethyl acetate, chloroform, and methanol consecutively. The plant residue was infused with 80 ºC demineralised water. After filtration, the water infusion was frozen at -80 ºC, then the extract was dried by using a freeze dryer. Hereby, a total of five extracts were prepared. Antioxidant activity of the extracts was tested using DPPH free radical scavenging, ABTS cation radical scavenging, CUPRAC cupric reducing antioxidant activity, metal chelating, and β-carotene-linoleic acid methods using a microplate reader. Fractions from the extracts were obtained with silica gel, C18, and sephadex LH-20 column packing materials. Structure identification and elucidation of isolated pure compounds were performed using one- and two-dimensional Nuclear magnetic resonance (1D- and 2D-NMR) and high-resolution mass spectrometry (HR-MS) spectroscopic methods. β-sitosterol and Di(2-ethylhexyl) phthalate were isolated from the hexane extract of P. sivasicum. The methanol extract afforded three compounds; annphenone, hyperoside, and daucosterol. The fatty acid profile of hexane extract was obtained using GC-MS. A phenolic profile study was conducted using LC-HR/MS. This master's thesis is the first study on the isolation of the secondary metabolites of Polygonum sivasicum Kit Tan & Yıldız that led to the identification of five compounds. Annphenone was isolated from a Polygonum genus for the first time. Hyperoside, detected as one of the major phenolics by LC-HR/MS, was also isolated during this study.