Guo H.-L.,Sericulture & Agri food Research Institute GAAS |
Guo H.-L.,Jiangxi Agricultural University |
Yu Y.-S.,Sericulture & Agri food Research Institute GAAS |
Wu J.-J.,Sericulture & Agri food Research Institute GAAS |
And 3 more authors.
Modern Food Science and Technology | Year: 2015
The effects of dimethyl dicarbonate (DMDC) and nisin treatment on the inactivation of Leuconostoc mesenteroides present in model juice and cell membrane functions were investigated. Combined treatment with DMDC and nisin had a fractional bactericidal concentration index of 0.38 (<0.5) against L. mesenteroides, indicating a strong synergistic bactericidal effect of DMDC and nisin. Scanning electron microscopy analysis showed no obvious changes in the cell morphology of L. mesenteroides treated with these antibacterial agents. Treatment with nisin alone increased the membrane permeability of approximately 7% of the cell population; this effect was stronger than that of treatment with DMDC alone. Despite this effect on membrane permeability and the resultant increase in the cellular uptake of extracellular polar substances, nisin treatment could not significantly reduce the loss of intracellular substances. The ultraviolet absorption value of L. mesenteroides cell suspension increased by approximately 60% after treatment with high concentrations of DMDC. To summarize, DMDC and nisin exhibited a synergistic effect on the inactivation of dehydrogenase activity in L. mesenteroides, but not on membrane permeability, loss of intracellular substances, and alteration of intracellular pH. ©, 2015, South China University of Technology. All right reserved.
PubMed | Sericulture & Agri food Research Institute GAAS
Type: Journal Article | Journal: PloS one | Year: 2014
Albendazole is a broad-spectrum parasiticide with high effectiveness and low host toxicity. No method is currently available for measuring albendazole and its metabolites in silkworm hemolymph. This study describes a rapid, selective, sensitive, synchronous and reliable detection method for albendazole and its metabolites in silkworm hemolymph using ultrafast liquid chromatography tandem triple quadrupole mass spectrometry (UFLC-MS/MS). The method is liquid-liquid extraction followed by UFLC separation and quantification in an MS/MS system with positive electrospray ionization in multiple reaction monitoring mode. Precursor-to-product ion transitions were monitored at 266.100 to 234.100 for albendazole (ABZ), 282.200 to 208.100 for albendazole sulfoxide (ABZSO), 298.200 to 159.100 for albendazole sulfone (ABZSO2) and 240.200 to 133.100 for albendazole amino sulfone (ABZSO2-NH2). Calibration curves had good linearities with R2 of 0.9905-0.9972. Limits of quantitation (LOQs) were 1.32 ng/mL for ABZ, 16.67 ng/mL for ABZSO, 0.76 ng/mL for ABZSO2 and 5.94 ng/mL for ABZSO2-NH2. Recoveries were 93.12%-103.83% for ABZ, 66.51%-108.51% for ABZSO, 96.85%-105.6% for ABZSO2 and 96.46%-106.14% for ABZSO2-NH2, (RSDs <8%). Accuracy, precision and stability tests showed acceptable variation in quality control (QC) samples. This analytical method successfully determined albendazole and its metabolites in silkworm hemolymph in a pharmacokinetic study. The results of single-dose treatment suggested that the concentrations of ABZ, ABZSO and ABZSO2 increased and then fell, while ABZSO2-NH2 level was low without obvious change. Different trends were observed for multi-dose treatment, with concentrations of ABZSO and ABZSO2 rising over time.