Homogenate-assisted high-pressure disruption extraction for determination of phenolic acids in Lonicerae Japonicae Flos.

An effective method based on the combined homogenate-assisted high-pressure disruption extraction (HHPDE) was applied to the extraction and determination of the main phenolic acid compounds from Lonicerae Japonicae Flos. The optimized HHPDE showed competitive advantage in yield (The extraction yields of NCA, CA, 3,5DCA and 4,5DCA in HHPDE were 1.21, 1.08, 1.06 and 1.17 fold higher than those in UAE), time-saving (<5 min) and relative low temperature requirement (4-16 °C) compared to HRE and UAE. Furthermore, the HHPDE method behaved a good repeatability and reproducibility according to the HPLC. The mentioned HHPDE method is firstly applied in the extraction and quantification of neochlorogenic acid chlorogenic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid in Lonicerae Japonicae Flos. This work provided an excellent alternative for the extraction and quantification of thermosensitive from plants.

An effective homogenate-assisted negative pressure cavitation extraction for the determination of phenolic compounds in pyrola by LC-MS/MS and the evaluation of its antioxidant activity.

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.

Variation of active constituents and antioxidant activity in pyrola [P. incarnata Fisch.] from different sites in Northeast China.

The variation of antioxidant activity and active components in pyrola [Passiflora incarnata Fisch.] from eight sites in Northeast China were investigated. Total phenolic and flavonoid contents were determined and varied within the range of 39.66-181.48 mg/g and 2.47-22.11 mg/g, respectively. Antioxidant activities were determined by scavenging activity against DPPH and ABTS, by a reducing power test and by a ß-carotene-linoleic acid bleaching test. The IC50 of Tahe samples determined by the DPPH test was 0.106±0.006 mg/mL which was very close to that of Vc (0.076±0.004 mg/mL). The Tahe samples had good antioxidant activity. Principal component activity analysis indicated that the Tahe samples of P. incarnata had the highest potential antioxidant properties, and may be a valuable antioxidant natural resource in the northeast of China.

An effective negative pressure cavitation-microwave assisted extraction for determination of phenolic compounds in P. calliantha H. Andr.

A novel negative pressure and microwave assisted extraction technique (NMAE) was first proposed and applied for extraction of phenolic compounds from pyrola. [C4MIM]BF4 aqueous solution was selected as extraction solvent. Optimal extraction conditions were microwave power 700 W, negative pressure -0.07 MPa, temperature 40 °C, liquid-solid ratio 20 : 1, ionic liquid (IL) concentration 0.5 M, extraction time 15 min. The predominance of NMAE was investigated by comparing with microwave-assisted extraction (MAE) and negative pressure cavitation extraction (NPCE) using a first-order kinetics equation. The C∞ values of the target compounds by NMAE were from 0.406 to 5.977 mg g⁻¹ higher than these by MAE and NPCE, which indicated that NMAE had higher extraction yields. The K values of NMAE were also the highest; it was testified that the target compounds could be transferred from matrix into solvent much more effectively by NMAE than by MAE and NPCE. In addition, the NMAE method was validated in terms of repeatability and reproducibility, the relative standard deviation for relative recovery was lower than 5.43 and 8.78%, respectively. Therefore, NMAE was a developed extraction technique for analytical sample preparation. The RP-HPLC-UV method was also successfully applied for the quantification of six target compounds in pyrola.