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In this study, aerial parts of dandelion were exposed to extraction by different solvents such as water, ethanol, methanol and glycerol and also their aqueous mixtures to compare the effect of extraction solvents on bioactive performance of the dandelion and also to show the effectiveness of hydroglycerolic extraction which is a green extraction process. Total phenolic content (TPC) and total flavonoid content (TFC) of the extracts were determined and also antiradical scavenging activities and antioxidant capacities of the samples were also evaluated. TPC and TFC of the samples ranged between 4.63-21.28 mg GAE/g and 1.16-14.38 mg CE/g, respectively. The highest TPC and TFC values were determined in aqueous extract of glycerol (75% w/w) compared to other solvents. Additionally, ABTS.+ and DPPH radical scavenging activity and ferric reducing capacity and antioxidant capacity values were determined for the extracts and the best solvent was also aqueous glycerol (75% w/w). [ABSTRACT FROM AUTHOR]

Hypericum perforatum is a widely used medicinal plant known that it has high bioactive performance due to its special biochemical compounds in its structure. The current study aimed to determine the optimum processing parameters of extraction conditions of bioactive constituents in H. perforatum by ultrasound application and its some bioactive performance. For this purpose, different processing variables namely sonication period (min), liquid/solid ratio and ethanol concentration (%) were selected to characterize the best conditions for extraction of H. perforatum. The statistical analysis results revealed that the most effective factor on the studied parameters was ethanol concentration and increment of ethanol level increased the characterized responses until a constant value. The constructed regression models fit very well with quite high determination of coefficients (R²>0.906). Total phenolic content was in the range of 39.54-63.55 mg GAE/g sample while total hypericin concentration ranged between 211.5-858.7 mg/kg. Multiple response optimization results revealed that the optimum extraction conditions would be at 47.6% ethanol concentration and 22.2 mL of liquid/solid ratio for 60 min ultrasonic process application. The results revealed that the optimized extraction conditions could be utilized for ultrasound extraction system by industrial application. [ABSTRACT FROM AUTHOR]

In the current study, the effect of glycerol -as a green solvent- addition into solvent mixture (50:50 ethanol:distilled water), on some biofunctional properties of Origanum onites L. was investigated. Response surface methodology (RSM) was used to detect the optimum conditions for the extraction process. Three variables namely glycerol concentration (X 1 : 1–9 g), extraction temperature (X 2 : 25–75 °C) and time (X 3 :10–30 min) were selected and also total phenolic content, total flavonoid content, antioxidant capacity and antiradical activity of O. onites extracts were determined. Analysis of variance (ANOVA) showed that glycerol incorporation significantly increased the total phenolic content and antioxidant activity (p < 0.05) of the samples. Maximum levels to obtain the highest bioactive properties (highest total phenolic content and antioxidant activity) were determined as to be 9 g of glycerol addition for the extraction conditions as 45.4 °C and 75 min. This study reports the effect of glycerol on bioactive properties of O. onites and suggests that glycerol can be used to produce hydroalcoholic extracts having higher bioactivity from Origanum genus. [ABSTRACT FROM AUTHOR]