Optimization of microwave-assisted extraction of bioactive compounds from aerial parts of Catharanthus roseus L.

In this study, the recovery of bioactive compounds from Catharanthus roseus L. using microwave-assisted extraction technology was evaluated and optimized through response surface methodology based on the Box-Behnken design. Microwave power (100-300 W), sample to solvent ratio (1:20-1:40 w/v) and microwave irradiation time (9-14 min) were independent variables. Optimization was performed using numerical technique with the aim of maximizing the extraction yield and total phenolic content. Based on the obtained results, the effect of all studied independent variables on the extraction yield and total phenolic content was significant (p<0.05). Optimal extraction conditions were microwave power of 250 W, microwave irradiation time of 11 min and sample to solvent ratio of 1:33 w/v. Under optimal conditions, the amount of extraction yield and total phenolic content were 18.21% and 118.40 mg GAE/g, respectively. The traditional Soxhlet method was used to evaluate the efficiency of microwave-assisted extraction technology. The traditional method performed better quantitatively (29.68±0.19%) but qualitatively (total phenolic content (16.19±0.18 mg GAE/g) and free radical scavenging activity (10.17±0.14%DPPHsc and 8.34±0.17%HOsc)) was far less effective than the microwave-assisted extraction method. The results revealed that more phenolic bioactive compounds can be achieved with the desired anti-radical activity in a shorter time and with less energy consumption using microwave-assisted extraction method.