Effect of Organic Solvents and Water Extraction on the Phytochemical Profile and Antioxidant Activity of Clitoria ternatea Flowers

Different extraction methods (organic solvent and water extraction with the assistance of heat or ultrasound) were investigated for their effects on the phytochemical profile and antioxidant activity of Clitoria ternatea flowers. For solvent extraction (30%, 50%, 80%, or 100% methanol, ethanol, or acetone), 50% ethanol was considered to be the best solvent for the extraction with an extract yield of 57.3%, a total anthocyanin content of 5.1 mg of cyanidin 3-glucoside equivalent/g of dry weight of extract, and a total phenolic content of 59.4 mg of gallic acid equivalent/g of dry weight of extract. Similar results were obtained for the best water extract at 50 degrees C for 1 h. A larger number of phytochemicals were identified using LC-MS analysis in the solvent extract (28 compounds). Kaempferol hexosyl-rhamnosyl-rhamnoside was the major compound detected in both the solvent and the water extract. Both extracts showed equally potent antioxidant activity in chemical [IC50 = 1.24 +/- 0.05 (solvent extract) and 1.18 +/- 0.07 (water extract) mg/mL in the 2,2-diphenyl-1-picryl-hydrazyl-hydrate assay] and cellular (75-80% inhibition) antioxidant assays.

Automated summary

The study found that using 50% ethanol as a solvent and extracting at 50 degrees Celsius for 1 hour yielded the highest amount of phytochemicals and antioxidant activity in Clitoria ternatea flowers. The solvent extract contained 28 identified compounds, with kaempferol hexosyl-rhamnosyl-rhamnoside being the major compound in both solvent and water extracts. Both extracts exhibited equally potent antioxidant activity in chemical and cellular assays.