Optimizarea metodei de extracţie cu ultrasunet a principiilor active din specia Cynara scolymus L.

Abstract

Background: Traditionally artichoke has been cultivated as a vegetable for human food in some Mediterranean regions and has been used in folk medicine since Roman times. Biological compounds of artichoke are mostly concentrated in leaves which contain high levels of caffeoylquinic acid derivatives. Obvious interest in this plant with hepatoprotective and cholesterol lowering qualities persuaded artichoke’s introduction in the collection of the Centre for the Cultivation of Medicinal Plants at the NicolaeTestemitsanu State University of Medicine and Pharmacy in 2002. This study is focused on optimized ultrasound-assisted extraction parameters of polyphenols and flavonoids from artichoke leaves without the risk of thermal degradation for their main phytoconstituents. Material and methods: In this study we have investigated the influence of some variables on extraction of polyphenols and flavonoids compounds from artichoke leaves based on ultrasound-assisted method. For this purpose an experimental design with 5 variables and 2 levels was used. The studied variables were: concentration of extraction solvent, temperature, extraction time and also the influence of parameters of ultrasonic processor pulse and amplitude; the total polyphenolic and flavonoid content were dependent variables. Results: The results of composite design indicated that the optimal extraction parameters were as follows: concentration of ethanol solution 70%, temperature 80°C, ultrasound time 30 minutes, with ultrasonic power output and pulse mode factor 100%. Conclusions: The influence of various parameters on the extraction of total flavonoid and polyphenolic content from artichoke’s leaves was studied. The ethanol concentration, the temperature and the time were found to be the most effective in extracting phenolic compouds with ultrasound-assisted method respectively.