Development of a Simple and Rapid HPLC-UV Method for Ultrasound-assisted Deep Eutectic Solvent Extraction optimization of Ferulic Acid and Antioxidant Activity from Ixora javanica Flowers

• The used of choline chloride-based Deep Eutectic Solvent as an optimal alternative solvent for phenolic compound extraction. • Validation of HPLC-UV method as a simple and rapid method for Ferulic acid determination. • Simultaneously optimization of ferulic acid and antioxidant activity using Response Surface Method. • Developing an extraction method that can replace the use of organic solvent for the extraction of ferulic acid as antioxidant compound and increase the extraction yields. In this work, we developed an environmental friendly extraction method to enhance ferulic acid yields and antioxidant activity of I. javanica flowers using Ultrasound-assisted extraction (UAE) method and Deep Eutectic Solvents as green solvent. To optimize the extraction method, response surface method analysis using Box Behnken designs were conducted. The results showed that the optimum extraction conditions for ferulic acid yields, DPPH scavenging capacity, ABTS scavenging capacity and Ferric-Reducing Antioxidant Power featured an extraction time of 40 min, 25% water content, and solid-to-liquid ratio of 1/27 g/mL. In this study, a rapid and simple analytical method was also validated for the quantification of ferulic acid in I. javanica flower extract using LC-UV method. The developed method was carried out under following condition: isocratic mobile phase of acetonitrile/formic acid pH 2.55 (30:70), a flow rate of 0.8 ml/min, detection at 321 nm, and C-18 column (250 mm x 4.6 mm, 5 µm). The ferulic acid and antioxidant activity of the extract obtained from the developed were higher than ethanolic extract under same extraction condition. In summary, the results of this study can provide more effective and efficient extraction method by applying the green extraction principle and be recommended to provide new potential antioxidant raw material.