Current Issue : July - September Volume : 2019 Issue Number : 3 Articles : 6 Articles
Quinonemethide triterpenoids, known as celastroloids, constitute a relatively\nsmall group of biologically active compounds restricted to the Celastraceae family and, therefore,\nthey are chemotaxonomic markers for this family. Among this particular type of metabolite,\npristimerin and tingenone are considered traditional medicines in Latin America. The aim of this\nstudy was the isolation of the most abundant celastroloids from the root bark of Maytenus chiapensis,\nand thereafter, to develop an analytical method to identify pristimerin and tingenone in the\nCelastraceae species. Methods: Pristimerin and tingenone were isolated from the n-hexane-Et2O\nextract of the root bark of M. chiapensis through chromatographic techniques, and were used as\ninternal standards. Application of a validated RP HPLC-PDA method was developed for the\nsimultaneous quantification of these two metabolites in three different extracts, n-hexane-Et2O,\nmethanol, and water, to determine the best extractor solvent. Results: Concentration values showed\ngreat variation between the solvents used for extraction, with the n-hexaneâ??Et2O extract being the\nrichest in pristimerin and tingenone. Conclusions: M. chiapensis is a source of two biologically\nactive quinonemethide triterpenoids. An analytical method was developed for the qualification and\nquantification of these two celastroloids in the root bark extracts of M. chiapensis. The validated\nmethod reported herein could be extended and be useful in analyzing Celastraceae species and real\ncommercial samples....
Uncomplicated, accurate and short analysis time analysis was elaborated for quantification of Articaine HCl (ART HCl) and Epinephrine (EPI). The electrochemical behavior of both articaine and epinephrine was carried out by applying differential pulse voltammetry (DPV) using Pencil graphite (PGE), carbon paste (CPE) and Nanomodified zirconium (ZRE) electrodes. The effect of experimental parameters has been investigated and optimized. The peak current linearity range were 6.62 × 10-5 - 50.60 × 10-5 mol L-1 for ART and 9.90 ×10-5 - 29.1 ×10-5 mol L-1 for EPI using (PGE), 3.90 × 10-5 -15.7× 10-5 mol L-1 for ART 4.97× 10-5 - 17.7 x10-5 mol L-1 for EPI, using (CPE) 5.96 × 10-5 - 23.4x10-5 mol L-1 for ART and 2.99×10-5- 22.5 × 10-5 mol L-1 for EPI using (ZRE). The suggested analysis has been applied for assay of ART and EPI in bulk, pharmaceuticals as well as in healthy human urine with good analytical results. Comparative validation steps were done contrasted with reference (HPLC) methods....
Aflatoxin B1 (AFB1) is a highly toxic mycotoxin found worldwide in cereals, food, and\nanimal feeds. AFB1 binds to human serum albumin (HSA) with high affinity. In previous\nexperiments, it has been revealed that reducing the binding rate of AFB1 with HSA could speed up\nthe elimination rate of AFB1. Therefore, we examined the ability of quercetin to compete with AFB1\nfor binding HSA by fluorescence spectroscopy, synchronous spectroscopy, ultrafiltration studies,\netc. It was shown that AFB1 and quercetin bind to HSA in the same Sudlow site I (subdomain IIA),\nand the binding constant (Ka) of the quercetin-HSA complex is significantly stronger than the\ncomplex of AFB1-HSA. Our data in this experiment showed that quercetin is able to remove the\nAFB1 from HSA and reduce its bound fraction. This exploratory work may be of significance for\nstudies in the future regarding decreasing its bound fraction and then increasing its elimination rate\nfor detoxification. This exploratory study may initiate future epidemiological research designs to\nobtain further in vivo evidence of the long-term (potential protective) effects of competing\nsubstances on human patients....
Alzheimer’s disease (AD) progresses due to beta amyloid aggregation and decreased acetylcholine level. Amyloid-β peptide (Aβ) formed by the continuous proteolytic processing of β-amyloid precursor protein (β APP) by β-secretase (BACE1) and γ-secretase (BACE2), plays a vital role in the pathogenesis of alzheimer’s disease (AD). Evaluated dipeptides and octapeptides exhibit inhibitory action against betasecretase enzyme. In-vitro enzyme inhibition assay was carried out for betasecretase enzyme and the IC50 value of DP I was found to be 0.0098 μg/ml and the standard donepezil (AChE inhibitor) was found to be 0.065 μg/ml. Based on the results the dipeptides and octapeptides were highly potent inhibition than control....
Rhodiola rosea has been used in folk medicine as ethanolic macerates for a long time. This\nstudy aims to provide a quantitative and qualitative analysis and comparison of different ethanolic\nRhodiola rosea rhizome macerates (35%, 70%, and 96% v/v) and accelerated solvent extraction (ASE)\nextracts prepared with 85% methanol, in order to shed light on the effectivity of different extraction\nmethods. Extract samples were analyzed by........................
The present work describes the optimization and validation of a highly selective and\nsensitive analytical method using solid phase extraction and liquid chromatography tandem mass\nspectrometry (SPE LC-MS/MS) for the determination of some frequently prescribed pharmaceuticals\nin urban wastewater received and treated by Sharjah sewage treatment plant (STP). The extraction\nefficiency of different SPE cartridges was tested and the simultaneous extraction of pharmaceuticals\nwas successfully accomplished using hydrophilic-lipophilic-balanced reversed phaseWaters® Oasis\nHLB cartridge (200 mg/ 6 mL) at pH 3. The analytes were separated on an Aquity BEH C18 column................
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