RESUMEN
To ensure the safety of the commercially available chenpi, a convenient and fast analytical method was developed for the determination of 133 pesticide residues in chenpi using gas chromatography-tandem mass spectrometry (GC-MS/MS). In this study, different extraction solvents, redissolution solvents and adsorbents were tested according to the recovery and purification effect to obtain a modified QuEChERS method. The samples were extracted with acetonitrile. During the clean-up step, octadecyl-modified silica (C18) and graphitized carbon black (GCB) were selected, and aminopropyl (NH2) was used instead of primary secondary amine (PSA) because of its weaker ion exchange capacity which had little effect on the recovery of ditalimfos. Samples were quantified by matrix-matched calibration with internal standards. All pesticides showed good linearity in the respective range, both with values of r 2 >â¯0.99. The average recoveries of the pesticides spiked samples ranged from 70.0% to 112.2% with the RSDs of 0.2%-14.4%. The modified QuEChERS method was validated and applied to twenty real samples. Five pesticides were found in eight batches, but no pesticide exceeded the maximum residue limits (MRL, MRL reference to European commission).
RESUMEN
(1E,4E)-1,7-Bis(4-hydroxyphenyl)hepta-1,4-dien-3-one (DHDK) is a novel curcuminoid analogue isolated from mistletoe. DHDK exhibits better anti-tumour activity, higher bioavailability and superior stability than curcumin. DHDK is difficult to isolate from Viscum coloratum, but it can be synthesised. MTT (methylthiazolyldiphenyl tetrazolium bromide) assay was used to evaluate the in vitro cytotoxic activity of synthesised DHDK on 12 cancer cell lines. Results showed that DHDK exhibited excellent potential as an anticancer agent, especially for breast and lung cancer. Efficacy was further evaluated in vivo by using MCF-7 breast cancer models. DHDK showed a dose-dependent relationship without weight reduction, mortality growth inhibition or tissue toxicity. Pharmacokinetics and tissue distribution statistics were determined by LC-ESI-MS/MS. This work provided preliminary data on this natural compound and could open up new prospects for changing related parameters to improve drug efficacy.
RESUMEN
A sensitive and robust LC-MS/MS method has been developed and validated to simultaneous determine the concentrations of tumulosic acid, dehydrotumulosic acid, polyporenic acid C, cinnamic acid, Atractylenolide I, Atractylenolide II, Atractylenolide III, glycyrrhizic acid, glycyrrhetinic acid, liquiritigenin and isoliquiritin in plasma from rats who received Ling-Gui-Zhu-Gan Decoction extract oral administration. The samples were prepared by a liquid-liquid extraction procedure using ethyl ether as the extraction solvent and schisandrin as the internal standard. Chromatographic separation was achieved using a Thermo Hypersil GOLD C18 column (2.1â¯mmâ¯×â¯100â¯mm, 1.9⯵m) and a gradient mobile phase consisting of acetonitrile-water with 0.1% formic acid. All of the analytes were quantified using negative and positive multiple reaction monitoring mode. The method was validated for selectivity, linearity, accuracy, precision, recovery, matrix effect and sample stability under various storage conditions, whose values are all fell in the acceptable limits. We report the lowest limit of quantification for tumulosic acid, dehydrotumulosic acid and polyporenic acid C as 2â¯ng/mL. This is the first study for simultaneous determination of so many analytes in rat plasma after oral administration of Ling-Gui-Zhu-Gan Decoction. This validated method was successfully used to study the pharmacokinetics of multiple compounds in rat plasma after oral administration of Ling-Gui-Zhu-Gan Decoction.
