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The extract was separated from the wooden layer between of walnut seed using pressurized hot water extraction (PHWE), pressurized liquid extraction (PLE), and perculation methods A central composite design was used to optimize the effective extraction variables. For achieving maximum extraction yield, total phenolic and minimum 2,2-Diphenyl-1-picrylhydrazyl (DPPH) IC 50 using PHWE and PLE the temperature was 105 °C and 78 °C, respectively but the pressure, static time, dynamic time for two methods were 19 bar, 18.06 min, and 28.34 min, respectively. The extraction yield and total phenols of optimum PHWE extract were more than optimum PLE and perculation extracts. The radical scavenging effects of the tested extracts were concentration dependent and all samples with the highest concentration of extracts had strong scavenging effect. The PHWE optimum extract exhibited considerably highest DPPH free radical scavenging activity with lowest IC 50 than PLE and perculation methods. [ABSTRACT FROM AUTHOR]

Background: The genus Artemisia belonging to the Compositae (Asteraceae) family and many traditional uses from the Artemisia species were reported. Artemisia absinthium is one of the species in this genus and commonly used in the food industry in the preparation of aperitifs, bitters, and spirits. Objective: Evaluation of the effect of different harvesting stages on the composition of essential oil and antioxidant capacity of A. absinthium. Materials and Methods: Essential oils from the aerial parts of A. absinthium, collected in three stages (preflowering, flowering, and after-flowering) from plants grown in the North Khorasan province of Iran were obtained by steam distillation and the chemical composition of the oils was analyzed by gas chromatography-mass spectrometry and antioxidant activity and total phenolic content were determined by 2-diphenyl-1-picrylhydrazyl assay and Folin-Ciocalteu method. Results: Analysis of the isolated oils revealed the presence of 44 compounds, mainly alpha-pinene, sabinene, beta-pinene, alpha-phellandrene, p-cymene and chamazulene. Alpha-phellandrene, and chamazulene were major compounds in preflowering stage, but beta-pinene and alpha-phellandrene were major in flowering and past-flowering stages. Flowering stage had highest yield and after flowering stage had lowest yield. The essential oil of preflowering stage had the highest amount of antioxidant compound (chamazulene). Preflowering stage with highest amount of phenolic compounds had the strongest antioxidant activity with the lowest amount of EC50. Conclusion: This study showed that the harvesting stage had significant effects on chemical composition and antioxidant properties of essential oils, and chamazulene is main compound for antioxidant activity in A. absinthium. [ABSTRACT FROM AUTHOR]

The extract was separated from roots of Scutellaria pinnatifida using perculation and pressurized liquid extraction (PLE). A circumscribed central composite (CCC) was used to optimize the effective extraction variables. For achieving maximum extraction yield via PLE the temperature, pressure, static time, dynamic time, and the solvent flow rate were adjusted 65.8 °C, 39.2 bar, 12.9 min, 18.9 min, and 0.76 mL/min, respectively. Ferric reducing antioxidant power (FRAP) (mmol/g) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (mg/mL) were evaluated and the highest antioxidant activity was observed from the PLE extract. The total phenolic and flavonoid content was calculated and a good correlation founded between phenolic content and antioxidant activity. The results indicated the root of this plant is a potential source of natural antioxidants and flavonoids. The PLE method is quicker and it has more extraction yield than perculation. [ABSTRACT FROM AUTHOR]