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Dec 2024 DOI 10.14302/issn.2835-2165.jfsh-24-5371
One of the primary goals and aims of studying chemistry in society is the promotion of the well-being of humanity and the sustainable utilization of the available resources. Chemistry has played a significant role in water treatment, food production, energy production, and medicine, among other critical areas of society. This study explored the utilization of liquid chromatography-mass spectrometry in the aspect of promoting food safety for human consumption. Various factors might affect the composition and storage of the food items in the society. Through the utilization of chemistry techniques such as (LC-MS), there can be Identification of the various aspects that require consideration in the Improvement of the different health and nutritional requirements that the food items are expected to have in society. As illustrated in this study, the analytical and technical aspects are highly influential in the determination of the proper measures for each component and the illustration of the various toxins that are likely to affect the overall food safety of the members of society in general.
Nov 2013 DOI 10.14302/issn.2326-0793.jpgr-13-291
A sensitive, specific and rapid high-performance liquid chromatography/tandem mass spectrometry (hplc–ms/ms) method has been developed and validated for the determination of danshensu (dss) in rat plasma in the present study. The analytes were separated on a c18 column (50 mm×2.1 mm, 1.7 μm) and a triplequadrupole mass spectrometry equipped with electrospray ionization (esi) source was applied for detection. The simple protein precipitation was applied to extract dss from the plasma (about 80%). The method was linear over the concentration ranges of 50–1000 ng/ml for dss. The lower limit of quantitation (lloq) of dss was 50 ng/ml. The intra-day and inter-day relative standard deviation (rsd) were less than 15% and the relative error (re) were all within 15%. Finally, the method was successfully applied to support the pharmacokinetic study after guanxinsu solution was orally administrated to the sprague–dawley rat, respectively.
Mar 2013 DOI 10.14302/issn.2328-0182.japst-12-173
A reliable, selective and sensitive liquid chromatography-tandem mass spectrometry (LC-ESI-MS/MS) assay has been proposed for the determination of febuxostat in human plasma using indomethacin as the internal standard (IS). The analyte and IS were extracted from 200 µL of human plasma via liquid-liquid extraction using methyl tert-butyl ether. Chromatography was performed on Hypurity C18 (100 mm × 4.6 mm, 5 µm) column under isocratic conditions. Detection of analyte and IS was done by tandem mass spectrometry, operating in negative ionization and multiple reaction monitoring mode. The deprotonated precursor to product ion transitions monitored for febuxostat and indomethacin were m/z 315.1 →271.0 and 356.1→312.0 respectively. The limit of detection (LOD) and limit of quantitation (LOQ) of the method were 0.0025 µg/mL and 0.05 µg/mL respectively. The linear dynamic range validated for febuxostat was 0.05-6.00 µg/mL. The intra-batch and inter-batch precision (% CV) was ≤ 7.1 % while the mean extraction recovery was > 87 % for febuxostat across quality control levels. The method was successfully applied to a bioequivalence study of 80 mg febuxostat tablet formulation in 14 healthy Indian male subjects under fasting and fed condition. The reproducibility in the measurement of study data was demonstrated by reanalysis of 110 incurred samples.
Jun 2023
Insulin is a frequent peptide hormone addition in serum-free mammalian cell culture media. It contributes in a variety of biological functions, including as promoting cell proliferation, cell cycle progression, and glucose uptake. However, it is unknown how stable insulin is under in vitro cell culture media treatment conditions. The instability of insulin in aqueous solutions has caused a number of issues, necessitating the development of new therapeutic strategies that can keep insulin stable and functioning. Such choices are required to accommodate updated insulin delivery guidelines as well as the storage and transportation of insulin. To preserve structural and functional integrity, protein medicines are frequently stabilized with antioxidants in aqueous solutions. In the present study, the effects of the antioxidants disodium ethylenediaminetetraacetic acid dihydrate (EDTA) and sodium selenite (Se) and their ability to scavenge free radicals on insulin stability in the medium Dulbecco's Modified Eagle Medium (DMEM) and Roswell Park Memorial Institute (RPMI) were examined. To investigate the stability of human recombinant insulin, in vitro serum-free DMEM and RPMI media were utilized for 5 days at 37˚C containing different EDTA and Se concentrations. Reversed phase high performance liquid chromatography (RP-HPLC) was used to detect and quantify insulin. Sodium dodecyl sulfate polyacrylamide gel (SDS-PAGE) electrophoresis was used to assess conformational stability. The results demonstrated that, when EDTA and Se were added separately to DMEM and RPMI media, insulin stability was improved compared to when neither compound was added.
Apr 2021 DOI 10.14302/issn.2689-2855.jan-21-3771
Ascorbic acid is a water-soluble vitamin (Vitamin C) essential for both the plants and animals for the metabolic process. In this study, the liquid chromatography-mass spectrometry (LC-MS) analytical technique was used to characterize the structural properties and isotopic abundance ratio to evaluate the effect of the Trivedi Effect®-Consciousness Energy Healing Treatment on L-ascorbic acid compared to the control sample. The ascorbic acid sample was divided into control and treated parts. Only the treated part received the Trivedi Effect®-Consciousness Energy Healing Treatment remotely by a well-known Biofield Energy Healer, Mahendra Kumar Trivedi. The control and treated samples showed a chromatographic peak at retention time (Rt) 1.8 minutes exhibited the deprotonated molecular ion peak at m/z 175 (M-H)- (calculated for C6H7O6-, 175.02) in the mass spectra. The peak area of the treated sample (12817614.01) was significantly increased by 8.81% compared to the control sample (11779918.9). The LC-MS based isotopic abundance ratio of PM+1/PM (2H/1H or 13C/12C or 17O/16O) in the treated ascorbic acid was significantly increased by 23.22% compared with the control sample. Thus,13C, 2H, and17O contributions from (C6H7O6)- to m/z 176 in the treated ascorbic acid were significantly increased compared with the control sample. The increased isotopic composition of the treated ascorbic acid might have altered the neutron to proton ratio in the nucleus. The changes in isotopic abundance could be due to changes in nuclei possibly through the interference of neutrino particles via the Trivedi Effect®-Consciousness Energy Healing Treatment. The increased isotopic abundance ratio and peak area of the treated ascorbic acid may increase the intra-atomic bond strength and its stability. This novel ascorbic acid after the Trivedi Effect®-Consciousness Energy Healing Treatment would be very useful to design more efficacious pharmaceutical formulations against scurvy, obesity, cardiovascular diseases, hypertension, rheumatoid arthritis, Alzheimer's disease, cancer, etc.
Sep 2019 DOI 10.14302/issn.2471-2140.jaa-19-2997
The paper explores the formation of a-oxoaldehydes during the interaction of glucose metabolites with hydroxyl or alkoxyl radicals. Hydroxyl radicals were generated under radiolysis of aqueous solutions, and alkoxyl radicals (t-BuO) were obtained in the model system tert-butyl hydroperoxide/Fe2+. High-performance liquid chromatography revealed that methylglyoxal was one of the organic products resulting from t-BuO-induced transformations of fructose-1,6-bisphosphate under hypoxic conditions. The interaction of lysine and methylglyoxal one of the main targets of a-oxoaldehydes in proteins was also studied. As chemiluminescence and EPR spectroscopy demonstrated, this reaction generates a methylglyoxal anion radical, a cation-radical of methylglyoxal dialkylamine and a superoxide anion radical. EPR signal of methylglyoxal-derived free radicals was observed in hypoxia, whereas only the trace amounts of these free radicals were recorded in the aerated reaction medium.
Apr 2019 DOI 10.14302/issn.2379-7835.ijn-19-2690
Objective To investigate the major constituents of Tinosporacordifolia Willd. growing on Mangiferaindica, and to evaluate the efficacy of their antibacterial and cytotoxicity activities. Methods The ethanolic stem extract of T. cordifolia was subjected to silica gel 60 column chromatography, thin layer chromatography and medium pressure liquid chromatography for isolation of the major compounds. Identification of purified compounds was achieved by spectroscopic methods.. The crude extract and purified compounds were screened for their antibacterial and cytotoxicity properties using standard procedures. Results Two alkaloids were purified and identified as Magnoflorin (1) and Tembetarine (2). These compounds showed high antibacterial activity against Bacillus cereus and Staphylococcus aureus with both MIC (32-64 µg/ml) and MBC (128-256 µg/ml). The cytotoxicity activity of the purified compounds and crude extract was determined using MTT colorimetric assay against L929 and HEK293 cell lines. This showed weak cytotoxicity activity with IC50 values of 1162.24 to 2290.00 µg/ml and 1376.67 to 2585.06 µg/ml towards L929 and HEK293 cell lines, respectively. Conclusion The major compounds present in ethanolic stem extract of T. cordifolia growing on M. indica were extracted, purified and identified. This study suggests that these compounds exhibit great potential for antibacterial activity with weak cytotoxicity activity. They may be useful for their medicinal functions.
Oct 2018 DOI 10.14302/issn.2328-0182.japst-18-2344
In recent years, the consumption of dietary supplements (DS) has increased worldwide. In Argentina, approximately 14 million DS units were sold between 2015 and 2017. The adulteration of DS with active pharmaceutical ingredients or their analogues has been reported. This represents an alarming emerging risk to public health. The aim of this work was to detect the possible adulteration of a DS marketed in Argentina for the treatment of erectile dysfunction. Initially, thin layer chromatography analysis of the DS capsules content suggested the presence of a major compound. For the isolation and purification of this compound, an easy method consisted of a liquid-liquid extraction (water/CH2Cl2) followed by re-crystallisation from ethanol, is reported. Spectroscopic techniques such as mono- and bidimensional nuclear magnetic resonance, Fourier transform infrared spectroscopy and mass spectrometry allowed its identification as tadalafil. A rapid and reliable method was developed for the quantification of tadalafil in this DS by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS). The mean content of tadalafil per capsule was 21.2 mg which represents a slightly higher value than that found in approved products in Argentina (5 or 20 mg per tablet). In addition, an undeclared alga was identified in the DS by microscopic techniques.
May 2016 DOI 10.14302/issn.2377-2549.jndc-15-923
A hybrid monolithic column was prepared using octavinyloctasilasesquioxane (OVS) as a monomer, benzoyl peroxide/dimethylacetamide (BPO/DMA) as initiator, ethylene glycol dimethacrylate (EDMA) as cross-linker, 1-dodecanol as porogenic agent and dimethylbenzene as cosolvent. A tidy skeleton, much bigger specific surface area (22.4 m2/g) and lower swelling property of the monolithic column with OVS added than the one without OVS added were determined with Scanning Electron Microscopy (SEM), Nitrogen adsorption/desorption measurements (BET) and swelling test with elute of different concentration of acetonitrile in water. Fourier-transform infrared spectra (FTIR) was taken to characterize the composition of groups. Moreover, a better separation performance for benzene series compounds under reversed phase liquid chromatography (RPLC) mode was obtained using the monolithic columns with OVS added than those without.