naphthoquinones and hyperoside

A novel and effective extraction method, namely negative pressure cavitation-microwave assisted extraction technique (NMAE), was developed for the preparation of extracts of Pyrola incarnata Fisch., which are rich in the main constituents hyperin, 2'-O-galloylhyperin and chimaphilin. Single factor experiments and Box-Behnken design (BBD) were combined with a response surface methodology to examine factors affecting extraction. Maximum extraction yields of hyperin, 2'-O-galloylhyperin and chimaphilin (1.339±0.029, 4.831±0.117 and 0.329±0.011mg/g, respectively) were achieved under the following optimised conditions: 700W microwave power, 50°C extraction temperature, 30:1mL/g liquid-solid ratio, -0.05MPa negative pressure, 55% ethanol concentration and 12min extraction time. First-order kinetics equation demonstrated that NMAE offered significant savings in extraction time, and enhancing extraction efficiency. Furthermore, NMAE extracts yielded excellent antioxidant activity (IC50 0.121mg/mL for DPPH 2.896mmol FeSO4/g DW FRAP).

Topics: Antioxidants; Gallic Acid; Microwaves; Naphthoquinones; Plant Extracts; Pressure; Pyrola; Quercetin

A novel extraction method, homogenate-assisted negative pressure cavitation extraction (HNPCE), was designed for the extraction and determination of the main phenolic compounds of Pyrola incarnata Fisch. by LC-MS/MS. The particle sizes and extraction yields in the process of homogenization were compared with conventional pulverization. The results showed that homogenization for less than 120 s could produce more suitable particle size powders for analyte extraction. The following NPCE parameters were optimized by a BBD test and under the optimal conditions, the maximum extraction yields of arbutin, epicatechin, hyperin, 2'-O-galloylhyperin and chimaphilin increased by 68.7%, 72.0%, 43.3%, 62.5% and 34.5% with respect to normal NPCE. The LC-MS/MS method was successfully applied for the quantification of five target compounds in pyrola, and the results of the precision test indicated a high accuracy of the present method for the quantification of the target compounds in pyrola. Furthermore, the antioxidant activities of the pyrola extracts were also determined. The results showed that pyrola had good antioxidant activities and it was a valuable antioxidant natural source.

Topics: Antioxidants; Arbutin; Catechin; Chromatography, Liquid; Gallic Acid; Naphthoquinones; Phenols; Plant Extracts; Pyrola; Quercetin; Reproducibility of Results; Tandem Mass Spectrometry