Two novel chalcone constituents, tarennane (1) and tarennone (2), together with nine known compounds, were isolated from the whole plant of Tarenna attenuata. By analysis of physical and spectroscopic data, the structures of new compounds were elucidated as (E)-4-[3-(4-hydroxy-3-methoxyphenyl)-acryl]-3,4,5-trimethoxycyclohexa-2,5-dienone (1) and 1,2-bis(3,5-dimethoxy-4-hydroxyphenyl)-3-hydroxypropan-1-one (2). These two compounds were tested for antioxidant activities in the MTT and DPPH assays. Compound 1 revealed potent antioxidant activities against H₂O₂-induced impairment in PC12 cells, but neither of them showed DPPH radical-scavenging activity with IC₅₀ values of 181.1 and 210.3 μM, respectively.

Cyfluthrin is a widely used pesticide. In this study, a sensitive and efficient magnetic molecularly imprinted polymer (MMIP) was prepared by surface molecular imprinting, which used functionalized Fe3O4 particles as magnetic cores. Cyfluthrin was extracted and enriched using magnetic molecularly polymer for analyzing pesticide residue of Chinese herbal medicines. The crystal type, microstructure, particle size, saturation magnetization, and characteristic functional groups of the synthesized MMIPs were analyzed by analysis equipment. The results of isothermal adsorption and kinetic adsorption indicated that MMIPs reached adsorption equilibrium at 30 min, with a maximum capacity of 4.9 mg g(-1), which had good adsorption performance, while selective adsorption experiments showed that MMIPs had higher affinity for cyfluthrin. Under the optimized conditions, the limit of detection (LOD) and the limit of quantification (LOQ) were 32.987 ng ml(-1) and 109.955 ng ml(-1), respectively. And linear range (30-3000ng ml(-1)) of cyfluthrin with correlation coefficient R-2=0.9979, and MMIPs were used in honeysuckle, the recoveries were 91.5%similar to 97.2%, and RSD was 5.35%similar to 8.32% (n = 3). It is indicated that the magnetic molecularly imprinted polymer can be used as an effective material for the specific separation of cyfluthrin from honeysuckle.

In this study, a novel magnetic solid phase extraction adsorbent was prepared, namely Fe₃O₄@SiO₂ as the carrier, quercetin as the template molecule, acrylamide (AM) as the functional monomer, ethylene glycol dimethacrylamide (EGDMA) as the crosslinker, 2,2’-azobisisobutyronitrile (AIBN) as the initiator to prepare magnetic molecularly imprinted polymer (MMIPs) with specific adsorption of quercetin by surface molecular imprinting technique. MMIPs were characterized by Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD) and Transmission electron microscope (TEM). The binding properties of MMIPs were evaluated by isothermal adsorption, kinetic adsorption and selective adsorption experiments. The results showed that the saturated adsorption capacity and adsorption time were 17.9 μmol/g and 20 min, respectively, and showed high selectivity for quercetin. Under optimized conditions, the limit of detection (LOD) and limit of quantitation (LOQ) were 55.327 ng/mL and 184.413 ng/mL, respectively. The recovery and RSD were 85.34-95.67% and 3.36-6.59, respectively. We successfully combined magnetic solid phase extraction with high performance liquid chromatography (MSPE-HPLC-UV) for the enrichment, separation and detection of quercetin in rat plasma. The results showed that the peak and half-life of quercetin in plasma were 1.5 h (32.310 μg/mL) and 3 h, respectively. The method was simple, rapid and efficient, and could be applied to the separation and detection of quercetin in complex matrices, and also provides a basis for the separation and identification of other natural chemical components.