Solvothermal-assisted in situ rapid growth of octadecylamine functionalized polydopamine-based permanent coating as stationary phase for open-tubular capillary electrochromatography.

In recent years, mussel-inspired polydopamine (PDA) based materials have been widely used as stationary phases for open-tubular capillary electrochromatography (OT-CEC) because of their various excellent properties. Nevertheless, the traditional synthesis routes of functionalized PDA-based capillary columns usually are time-consuming and limited in aqueous solutions. Herein, we report a facile and rapid route to prepare octadecylamine (ODA) functionalized PDA coated OT-CEC columns in organic solvents via a novel one-step in situ solvothermal-assisted coating strategy. Through this developed solvothermal-assisted approach, the growth rate of ODA/PDA coating was significantly speeded up and their hybrid coating process on the capillary inner surface could be rapidly completed in 60 min. The successful preparation of the solvothermal-assisted ODA/PDA hybrid coating were systematically characterized and confirmed by several methods. The influence of the preparation parameters on the formation of hybrid coating and the separation ability of the ODA/PDA modified columns were systematically explored. Consequently, the high-efficiency baseline separation of four kinds of neutral, acidic and basic analytes were achieved based on the ODA/PDA modified columns. The repeatability of the solvothermal-assisted ODA/PDA coated column was also studied, and the relative standard deviations for intra-day, inter-day and column-to-column were all less than 5%. Additionally, the solvothermal-assisted ODA/PDA modified column exhibited good stability and long lifetime.

Response Surface Optimized Infrared-Assisted Extraction and UHPLC Determination of Flavonoid Types from Flos Sophorae.

Single-factor experiment and Box-Behnken design were applied to optimize the infrared-assisted extraction (IRAE) of rutin, quercetin, kaempferol, and isorhamnetin from Flos sophorae. Four factors (extract solvent, solid-liquid ration, extraction time, infrared power) affecting the extraction yield of flavonoids were studied. Under optimized conditions the extraction yield was 33.199 ± 0.24 mg/g, which substantially improved, compared with heating reflux extraction (HRE) and ultrasonic-assisted extraction (UAE), while extraction time was only 9 min. The eluents were rich in 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azobis (2-methyl-propionamidine) dihydrochloride radical scavenging potential (IC50 of DPPH: 53.44 ± 0.01 µg/mL, oxygen radical absorbance capacity (ORAC): 3785.83 ± 52 µmol/g) than the extracts obtained by HRE and UAE. In addition, an ultra-high performance liquid chromatography method was optimized for the identification and quantification of the tested flavonoids, and the method was validated based on its correlation coefficient (r), reproducibility (RSD, n = 5), and recovery values, which were 0.9994-0.9998, 0.74-1.83%, and 97.78-102.94%, respectively. These results confirmed that high extraction yield of flavonoids results in stronger antioxidant values and response surface methodology optimization of IRAE is a promising alternative to traditional extraction techniques for flavonoids from medicinal plants.

Application of NIR and MIR spectroscopy for rapid determination of antioxidant activity of Radix Scutellariae from different geographical regions.

INTRODUCTION: The beneficial health effects of traditional Chinese medicines are often attributed to their potent antioxidant activities, usually established in vitro. However, these wet chemical methods for determining antioxidant activities are time-consuming, laborious, and expensive. OBJECTIVES: This study was conducted to establish a rapid determination of antioxidant activity of Radix Scutellariae using near-infrared (NIR) and mid-infrared (MIR) spectroscopy. MATERIAL AND METHODS: Antioxidant capabilities were evaluated using 2,2-diphenyl-1-picrylhydrazyl hydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays. The total flavonoid contents (TFCs) of Radix Scutellariae were measured by the aluminium chloride colorimetric method. The same sample was then scanned using NIR and MIR spectroscopy. Chemometrics analysis using partial least-squares (PLS) regression was performed to establish the models for predicting the antioxidant activities of Radix Scutellariae. RESULTS: A better predictive performance was achieved using PLS models based on NIR data. The determination coefficient (R(2)) and the residual predictive deviation (RPD) for the validation set were 0.9298 and 2.84 for DPPH, and 0.9436 and 2.66 for TFCs, respectively. MIR-PLS algorithms gave a slightly lower reliability (R(2) = 0.9090 and 0.9374, RPD = 2.01 and 2.42, for DPPH and TFC, respectively). Very comparable results for ORAC were obtained with the two methods. CONCLUSION: The developed spectroscopic method can be successfully applied in high-throughput screening of the antioxidant capability of Radix Scutellariae samples. It can also be a viable and advantageous alternative to laborious chemical procedures.

[Optimization of Aqueous Two-Phase Extraction of Polysaccharide from Schisandra chinensis Using Response Surface Methodology with Box-Behnken Design].

Objective: To optimize the extraction condition of polysaccharide from Schisandra chinensis. Aqueous two-phase extraction（ ATPE） method was used, based on Box-Behnken design with Response surface methodology（ BBD-RSM）. Methods: solvent volume,K2HPO4 and PEG6000 were selected as the investigation factors by the single-factor experiment, and the overall desirability（ OD）of phase volume ratio, partition coefficient and extraction rates were the reponse value. BBD-RSM was used to optimize the extraction process. . Results: The optimal parameters were as follows,the solvent volume was 5 m L,the addition amount of K2HPO4 was 1. 0 g, the addition amount of PEG6000 was 1. 8 g and centrifugation time was 9 min, which indicated that the model had a good predictability. The predicted value was 0. 950,and the deviation between observed and predicted values was 3. 94% Conclusion: The ATPE technology is easy to operate and cost-effective for the extraction of polysaccharides from Schisandra chinensis.