RESUMO
AIM To establish a GC-MS method for the simultaneous content determination of sixteen pesticide residues in Lycii Fructus and perform safety assessment.METHODS The analysis was performed on DB-5MS chromatographic column(30 m×0.25 mm,0.25 μm)subjected to the programmed heating,with splitless injection of 1.0 μL dissolved sample at a flowing rate of 1.0 mL/min.Other parameters were as follows:injection port temperature of 250℃,electron impact ionization(EI),electron energy of 70 eV;ion source temperature of 230℃,multi-reaction monitoring mode,and collision gas.of high-purity N2.Pesticide residues with relatively high dietary risk were analyzed and discussed with regard to residue levels,dietary intake risk,risk ranking and cumulative exposure assessment.RESULTS Sixteen pesticides showed good linear relationships within their own ranges(r≥0.994 4),whose average recoveries were 70%-114%,with the RSDs of less than 2%.The highest average cyfluthrin residue of 0.999 2 mg/kg in Lycii Fructus of production regions and the highest average cypermethrin residue of 0.088 4 mg/kg in Lycii Fructus commodities were both detected.In Lycii Fructus of production regions with chronic hazard index(HI)value of 0.012 9 and acute HI value of 0.065 5 and their commodities with chronic HI of 0.001 2 and acute HI of 0.005 4,the pesticide residue of cypermethrin was the leading cause of chronic and acute dietary risk,and additionally,pyridaben within maximum residue limit(MRL)was the only detectectable highly toxic pesticide among the other most concerning pestcides of deltamethrin,pyridaben,chlorpyrifos,dichlorvos and methidathion.CONCLUSION There exist pesticide residues within MRL values in some samples of Lycii Fructus and the use of cypermethrin should be well-controlled.
RESUMO
The current study explored the hepatotoxicity among closed-ring genipin, open-ring tautomer of genipin and gardenia blue that generated from genipin and amino acid reaction using HepaRG cells to identify the material basis of genipin-induced hepatotoxicity in vitro. The effects of temperature, pH value and different kinds of amino acids on the chemical structure tautomerism between closed-ring and open-ring tautomer of genipin and the production of gardenia blue were investigated firstly, which aimed to explicit the conditions that could distinguish the closed-ring genipin and its open-ring tautomer, and the conditions generating gardenia blue, which were applied to prepare different kinds of gardenia blue; the CCK-8 kit was employed to analyze the hepatotoxicity of closed-ring genipin, open-ring tautomer of genipin and gardenia blue. From the results, it was found that, the structure transformation from close-ring to open-ring of genipin could be inhibited under the condition with acid environment; being essential groups to generate gardenia blue, the primary amino group and the open-ring tautomer of genipin reacting to generate the dihydropyridine ring was probably the key structure of gardenia blue; the structure characteristics existed apparent distinction at the reactive temperature of 37 ℃ and 80 ℃; compared to the culture condition with pH = 7.4, the concentration of genipin with close-ring in culture medium was significantly increased at pH = 5, but the cell viability did not decreased; the cell toxicity of gardenia blue was apparently lower than open-ring tautomer of genipin, and even some kinds of gardenia blue showed growth promoting effect on HepaRG cells. Here, it was suggested potentially that open-ring tautomer of genipin be the important material basis to induce hepatotoxicity, which could provide a cue and lay a foundation for the elucidation of the underlying mechanism of genipin-induced hepatotoxicity.