In this study, various extracts of Hypericum perforatum L. were investigated in terms of their extraction yields. For this purpose, five solvent systems including 70%EtOH-30% H2O (A), 50%EtOH-50% H2O (B), 30%EtOH-70% H2O (C), 100% EtOH (D), and 100% H2O (E) were used. Ultrasonic-assisted extraction was used for extraction and extraction processes were performed at different temperatures (30°-70oC) and extraction times (30-70 min.). The optimum extraction conditions for H. perforatum was determined based on extraction yield, total phenolic contents, and DPPH radical scavenging activities of the crude extracts, as well. The best ultrasound extraction conditions are achieved in the presence of 70%EtOH-30% H2O solvent system, for 40 min, at 30°C for H. perforatum.

For a long time, many cultures around the world have used Tribulus terrestris L. in the prevention and treatment of various diseases. In this study, the antioxidant activity and total phenolic and flavonoid content of extracts obtained with various solvents from T. terrestris plant collected from different localities in Kahramanmaraş were investigated. In addition, the fixed oil content of the extracts was examined by GC-MS analysis and as a result, 26 different fatty acids were determined. The main fatty acid components of plant extracts are linoleic acid, oleic acid and palmitic acid. The total phenolic substance value of plant extracts varies between 2.20-18-77 mg g-1, total flavonoid amount varies between 0.06-0.50 mg g-1, FRAP value varies between 6.16-23.50 µg g-1 and DPPH value varies between 1.54-10.54 µg mL-1. It was observed that the solvents used in extraction affected the bioactivity values rather than the locations. Although the absorbance values of the extracts obtained with hexane were high, low extract yield affected the results. The highest values in all characters examined were obtained from ethanolic extracts.