Microwave Ultrasound Assisted Extraction: Determination of Quercetin for Antibacterial and Antioxidant Activities of Iranian Propolis

Propolis was used as medicine, cosmetic and beverage additives since past decades. The most important active compounds in the propolis are phenolic and flavonoids, which are in the resin category. The purpose of this study was to measure the total amount of flavonoids and quercetin in propolis of northern Iran and compare obtain data with different extraction methods. The soxhlet, maceration and microwave-ultrasound-assisted extraction (MUAE) were conducted for comparison of the extraction efficiency. Total amount of flavonoids measured by Spectrophotometry and the amount of quercetin were determined by using high performance liquid chromatography (HPLC). Here in this work, the best extraction yield for the total flavonoids was obtained 70.88 % and for quercetin was 44.53% at 300 W, 1.5 min for microwave and ultrasound 10 min and 40 °C. Also extraction yield of quercetin for soxhlet (as reference method) was determined 67.85% and for maceration was 13.9%. UV-vis, HPLC and FTIR analyses were used to determine the extraction yield and chemical structure of the active compounds. Then antioxidant and antibacterial effects of propolis extract were evaluated and the obtained results were compared with the related literature.