Peperomia pellucida Kunth. contain phenolic compounds and known to have efficacy as antihypertensive by the mechanism of inhibition of angiotensin-converting enzyme (ACE) and antioxidants. Microwave-assisted extraction (MAE) method has great potential for extracting the active compound in plant. In this study, MAE method was developed to obtain optimum total phenolic content, angiotensin-converting enzyme inhibitory activity, and antioxidant activity from Peperomia pellucida Kunth. MAE efficiency parameters used were ethanol concentration, sample to solvent ratio, extraction time, and microwave power. The analysis was performed using response surface methodology (RSM). Total phenolic content was measured by Folin-Ciocalteu method, while ACE inhibitory activity was evaluated using ACE kit-WST, and antioxidant activity was measured by ferric-reducing antioxidant power (FRAP) method. The optimum conditions of MAE for total phenolic content (49.78 mg GAE/g extract) were 80% ethanol, sample-solvent ratio of 1:12, extraction time of 2 min, and power of 30%. The optimum ACE inhibitory activity (54.73% at a concentration of 100 µg/mL) and antioxidant capacity of FRAP method (130.33 µmolGAE/g extract at a concentration of 32.26 µg/mL) were obtained at 80% ethanol, ratio of 1:12, time of 2 min, 70% power, and 65% ethanol, ratio of 1:12, time of 1 min, and 70% power respectively. The analysis of Pearson correlation indicated that there was no correlation between total phenolic content with ACE inhibitory activity and antioxidant activity.

Keywords: ACE, FRAP, microwave-assisted extraction, Peperomia pellucida, phenolic compounds, RSM