Targeted UHPLC-ESI-MS/MS Analysis of Selected Neurotransmitters, Tryptophan and Its Metabolite Kynurenine in Tau Transgenic Rat Brain Tissue: A Pivotal Study

Neurotransmitters (NT) are widely distributed in the central nervous system. These molecules are important for many physiological processes and the function of the immune system. Imbalance of NT are linked to numerous neurological disorders and diseases, including tauopathies. Here, a targeted approach based on on-line combination of ultra-high performance liquid chromatography with tandem mass spectrometry was validated and applied to the quantitative analysis of nine NT (acetylcholine, choline, aspartic acid, asparagine, glutamic acid, glutamine, pyroglutamate, γ-aminobutyric acid, N-acetyl-L-aspartic acid), tryptophan and its metabolite kynurenine in brain tissue samples of a rat model for tauopathy. The applied analytical method was characterized by excellent validation parameters for all analytes, such as limits of detection in the range of 0.01–1.70 µg/mL, regression coefficients of the calibration curves ≥ 0.9946, intra-day and inter-day precision expressed as coefficient of variation in the range of 0.6–11.9% and 0.6–14.4%, and accuracy in the range of 87.6–107.1% and 87.2–119.6%. Our analytical approach led to the identification of increased levels of choline and γ-aminobutyric acid in pons, and elevated concentration levels of pyroglutamate in medulla oblongata. These findings indicate that NT could play a valuable role in the study and clarification of neuroinflammation and neurodegenerative diseases.

Biochemical analyses for dental age estimation: a review

Background For various legal and forensic scenarios, establishing an individual’s age, both living and dead, plays a crucial role. Various morphological, radiographic, and molecular methods can be used for age estimation. In children and adolescents, age estimation is based on the established developmental stages. However, in adults, where the development ceases into maturation, the degenerative changes play a role in determining the age. Main body of the abstract In the natural aging process, several molecular changes occur most commonly in the long-living proteins and hard tissues like the teeth and bone. These molecular changes gradually lead to alterations in several organs and organ systems, which can be quantified and correlated with age, including aspartic acid racemization, collagen crosslinks, advanced glycation-end products, and mitochondrial DNA mutations. Short conclusion Among the above methods, the racemization of aspartic acid can be considered as the most precise method. The main advantage of using aspartic acid racemization is that the sample can be collected from tissues (teeth) protected from various environmental and nutritional factors. If all the confounding factors are stable, the utilization of advanced glycation-end products can also be considered valuable. Environmental factors like lead accumulations may also help determine the age. However, further studies need to be conducted, focusing on providing a more standardized method. This review provides a concise summary of the biochemical techniques that can be used for estimation of age.

A Highly Stable Eu−MOF Multifunctional Luminescent Sensor for the Effective Detection of Fe3+, Cr2O72−/CrO42− and Aspartic Acid in Aqueous Systems

Heavy metal ions were common pollutants in water pollution. Amino acids, as important substances in organisms, participate in many life activities. The detection of heavy metal ions and amino acids...

SYNTHESIS OF CR(III)-ASPARTATE AND CU(II)-ASPARTATE COMPLEXES AS ANTIDIABETIC COMPOUND

The synthesis of Cr(III)-Aspartate and Cu(II)-Aspartate complexes has been successfully conducted by reacting CrCl3·6H2O and CuCl2·2H2O metals with aspartic acid. Therefore, this study aimed to synthesize Cr(Asp)2Cl2 and Cu(Asp)Cl2 as well as test their antidiabetic effects. The synthesis results of Cr(Asp)2Cl2 and Cu(Asp)Cl2 in the form of light purple and blue solids were 0.3001 g and 0.3095g with a yield of 95.14% and 95.02%, respectively. Furthermore, the antidiabetic test used 27 male mice (Mus musculus) with nine treatments for 21 days. The data obtained were analyzed statistically using analysis of variance, and the antidiabetic activity was expressed in percent glucose lowering. The result showed a decrease in blood glucose levels in mice after alloxan induction, with percent glucose lowering (%GL) values of 74.1874% for Cr(Asp)2Cl2 and 76.1337% for Cu(Asp)Cl2 compounds. Therefore, the Cr(Asp)2Cl2 and Cu(Asp)Cl2 compounds can be used as antidiabetic in mice which are also potentially used as metal-based drugs for the treatment of DM.

Study of Epilobium angustifolium L. amino acids content by HPLC method

The use of plant raw materials is one of the areas of modern pharmaceutical science in the production of herbal drugs. The genus Epilobium counts more than 200 species, many species of which are used in traditional medicine. Among the Epilobium species, Epilobium angustifolium is one of the well-known medicinal plants which have been used worldwide in habitual medicine. There is insufficient information in the literature on the biologically active substances of Epilobium angustifolium L. The presence of three major polyphenol groups: phenolic acids, flavonoids, and ellagitannins were identified in E. angustifolium extracts. Traditionally, the infusion of leaves of this plant could be useful for headaches, cold and gastrointestinal disorder. The Epilobium angustifolium L. as an insufficiently studied plant is a promising object of study, including amino acids composition. To assess the relationship between the production of primary metabolites and their possible therapeutic properties, we analyzed the amino acid profile of the plant Epilobium angustifolium used in traditional medicine. The study of compounds generated by plants as a result of defense mechanisms permits an understanding of the molecular mechanism involved in their medicinal properties. The aim. Thus, the aim of the study was to conduct an HPLC analysis of the amino acids of E. angustifolium to establish the prospects for the use of the raw materials in medical and pharmaceutical practice. The results of the current study will be used in further breeding programs aimed to obtain an industrial form of E. angustifolium suitable for pharmaceutical and food applications. Materials and methods. The determination of amino acids composition of Epilobium angustifolium was conducted using Agilent 1200 (Agilent Technologies, USA). Results. The HPLC method identified sixteen free amino acids and seventeen bound amino acids in the Epilobium angustifolium herb. The studies have shown that Epilobium angustifolium L. herb is mainly composed of free amino acids such as L-phenylalanine (1.65 µg/mg), L-glutamic acid (1.51 µg/mg), L-arginine (1.24 µg/mg), L-alanine (0.98 µg/mg) and L-aspartic acid (0.57 µg/mg), which were presents in the greatest amount. The dominant bound amino acids in the studied raw material were L-glutamic acid, L-aspartic acid, L-leucine, and L-alanine, the content of which was 32.37 µg/mg, 10.59 µg/mg, 8.70 µg/mg, and 6.22 µg/mg respectively. Conclusions. Using the HPLC method determined the amino acids in the herb of Epilobium angustifolium L. The concentrations of L-aspartic acid, L-glutamic acid, L-arginine, L-alanine and L-phenylalanine are predominate among free and bound amino acids in the Epilobium angustifolium L. herb. The result shows that Epilobium angustifolium L. is the source of amino acids, so the use of this plant raw material for new remedies is possible in the future