A new and highly efficient source of t-resveratrol: Cephalaria Syriaca (L.) Roem. & Schult

Recently, interest in bioactive plant compounds has increased due to their properties in preventing and treating diseases like cancer and neurodegenerative disorders. In this study, caffeic acid and t-resveratrol were extracted from Cephalaria syriaca seeds using ultrasonic assisted extraction (UAE) and supercritical carbon dioxide (Sc-CO₂) extraction methods. Independent variables were temperature (40, 60, 80 °C), pressure (130, 215, and 300 bar), and co-solvent ratio (ethanol v/v (3.0, 6.5, 10.0%)) were selected. While extraction process conditions were optimized using response surface methodology, polyphenols were determined by an HPLC system. As a result of the Sc-CO₂ experimental studies, maximum caffeic acid (88.75 ± 1.71 μg/g dw) was obtained at 80 °C, 130 bar, and 10% ethanol conditions and maximum t-resveratrol (2949.45 ± 51.78 μg/g dw) was obtained at 60 °C, 130 bar, and 6.5% ethanol conditions. The results of the UAE method were found to be 76.21 ± 2.40 μg/g dw caffeic acid and 4629 ± 123.2 μg/g dw t-resveratrol.