Abstract:

Response surface methodology (RSM) was used to optimize the process conditions for microwave-assisted
extraction of chlorogenic acid from Eucommia ulmoides leaves. Based on single-factor tests, a quadratic regression model
was established to reveal the individual and cross-interaction effects of solid-liquid ratio, extraction time, microwave power
and ethanol concentration on the yield of chlorogenic acid. The optimal extraction conditions were achieved to be powder
size of 80 mesh, solid-liquid ratio of 1:26 (g/mL), extraction time of 2.5 min, microwave power of 722 W, and ethanol
concentration of 30%. Under the optimal conditions, the actual yield of chlorogenic acid was 29.74 mg/g, which agreed with the
theoretically predicted value. Meanwhile, the chlorogenic acid obtained in this study at a high dose (20 mg/kg) had a significant
and stable antihypertensive effect in spontaneously hypertensive rats.

Key words: response surface methodology, microwave-assisted extraction, Eucommia ulmoides leaf, chlorogenic acid, hypotensive effect