Bioactive Compounds of Green Phenolic Extracts Obtained via Microwave-Assisted Extraction of Species Grown in Greece.

The purpose of the present study was to compare the polyphenolic compounds extracted from five species grown in Greece; , , , , and using the Microwave-Assisted Extraction (MAE) process. To maximize the extraction yield (EY), total phenolic compounds (TPC), hypolaetin (HYP) and isoscutellarein (ISC), derivative contents (target phenolics), the response surface methodology was used for . A Box-Behnken design was undertaken to study the effect of ethanol concentration (30-100%), extraction temperature (40-100 °C), and extraction time (5-25 min) on the responses. The optimal MAE parameters were 87.9% (/) ethanol, 25 min, and 100 °C. Under these conditions, there was a good agreement between experimental and predicted values, indicating the reliability of the predictions for extracts. Phenolic compounds were then extracted under these conditions, from the five species under investigation. The TPC, total flavonoid content (TFC), antioxidant activity based on DPPH, ABTS, and FRAP assays as well as the phenolic profile of different extracts, evaluated via HPLC-DAD-MS, were compared. A similar phenolic profile was observed among the five species, with HYP and ISC derivatives showing variations in their contents as a function of species. MAE extracts could be considered green and natural antioxidants for medicinal, cosmetic, and food purposes, accompanied by sustainable approaches.