The Application of Green Solvents in the Synthesis of S-Heterocyclic Compounds-A Review.

Cyclic organic compounds containing sulfur atoms constitute a large group, and they play an important role in the chemistry of heterocyclic compounds. They are valuable intermediates for the synthesis of other compounds or biologically active compounds themselves. The synthesis of heterocyclic compounds poses a major challenge for organic chemists, especially in the context of applying the principles of "green chemistry". This work is a review of the methods of synthesis of various S-heterocyclic compounds using green solvents such as water, ionic liquids, deep eutectic solvents, glycerol, ethylene glycol, polyethylene glycol, and sabinene. The syntheses of five-, six-, and seven-membered heterocyclic compounds containing a sulfur atom or atoms, as well as those with other heteroatoms and fused-ring systems, are described. It is shown that using green solvents determines the attractiveness of conditions for many reactions; for others, such use constitutes a real compromise between efficiency and mild reaction conditions.

Preliminary Report on the Influence of Acute Inflammation on Adiponectin Levels in Older Inpatients with Different Nutritional Status.

Inflammation can be triggered by a variety of factors, including pathogens, damaged cells, and toxic compounds. It is a biological response of the immune system, which can be successfully assessed in clinical practice using some molecular substances. Because adiponectin, a hormone released by adipose tissue, influences the development of inflammation, its evaluation as a potential measure of inflammation in clinical practice is justified. In the present contribution, statistical comparison of adiponectin concentration and selected molecular substances recognized in clinical practice as measures of inflammation were utilized to demonstrate whether adipose tissue hormones, as exemplified by adiponectin, have the potential to act as a measure of rapidly changing inflammation when monitoring older hospitalized patients in the course of bacterial infection. The study showed no statistically significant differences in adiponectin levels depending on the rapidly changing inflammatory response in its early stage. Interestingly, the concentration of adiponectin is statistically significantly higher in malnourished patients than in people with normal nutritional levels, assessed based on the MNA. According to the results obtained, adiponectin is not an effective measure of acute inflammation in clinical practice. However, it may serve as a biomarker of malnutrition in senile individuals.

Novel Thiourea and Oxime Ether Isosteviol-Based Anticoagulants: MD Simulation and ADMET Prediction.

Activated blood coagulation factor X (FXa) plays a critical initiation step of the blood-coagulation pathway and is considered a desirable target for anticoagulant drug development. It is reversibly inhibited by nonvitamin K antagonist oral anticoagulants (NOACs) such as apixaban, betrixaban, edoxaban, and rivaroxaban. Thrombosis is extremely common and is one of the leading causes of death in developed countries. In previous studies, novel thiourea and oxime ether isosteviol derivatives as FXa inhibitors were designed through a combination of QSAR studies and molecular docking. In the present contribution, molecular dynamics (MD) simulations were performed for 100 ns to assess binding structures previously predicted by docking and furnish additional information. Moreover, three thiourea- and six oxime ether-designed isosteviol analogs were then examined for their drug-like and ADMET properties. MD simulations demonstrated that four out of the nine investigated isosteviol derivatives, i.e., one thiourea and three oxime ether ISV analogs, form stable complexes with FXa. These derivatives interact with FXa in a manner similar to Food and Drug Administration (FDA)-approved drugs like edoxaban and betrixaban, indicating their potential to inhibit factor Xa activity. One of these derivatives, E24, displays favorable pharmacokinetic properties, positioning it as the most promising drug candidate. This, along with the other three derivatives, can undergo further chemical synthesis and bioassessment.

Evaluation of Selected Parameters of Oxidative Stress and Adipokine Levels in Hospitalized Older Patients with Diverse Nutritional Status.

Malnutrition is classified as one of the Giant Geriatric Syndromes. It carries serious consequences, such as sarcopenia or depression, which lead to functional disability. The main objective of this study was to identify parameters of oxidative stress and adipokines, which may be potential biomarkers of malnutrition in hospitalized older patients. During the study, selected parameters were determined in 137 senile patients, taking into account their nutritional status determined according to the Mini Nutritional Assessment (MNA), as well as an additional tool, namely the Geriatric Nutritional Risk Index (GNRI). Leptin and resistin were determined as the parameters with statistically significant differences between the patients classified according to the MNA. This phenomenon was confirmed using the GNRI classification. However, additional parameters for which differences were observed include the oxidized low-density lipoprotein level and activity of glutathione peroxidase. In conclusion, the determination of the mentioned markers in hospitalized senile patients as an adjunct to the routine assessment of nutritional status might be suggested to identify the early risk of malnutrition so that a personalized nutritional therapy can be implemented as early as possible.

Quantitative Structure-Activity Relationship Analysis of Isosteviol-Related Compounds as Activated Coagulation Factor X (FXa) Inhibitors.

Stevioside, one of the natural sweeteners extracted from stevia leaves, and its derivatives are considered to have numerous beneficial pharmacological properties, including the inhibition of activated coagulation factor X (FXa). FXa-PAR signaling is a possible therapeutic target to enhance impaired metabolism and insulin resistance in obesity. Thus, the goal of the investigation was a QSAR analysis using multivariate adaptive regression splines (MARSplines) applied to a data set of 20 isosteviol derivatives bearing thiourea fragments with possible FXa inhibitory action. The best MARS submodel described a strong correlation between FXa inhibitory activity and molecular descriptors, such as: B01[C-Cl], E2m, L3v, Mor06i, RDF070i and HATS7s. Five out of six descriptors included in the model are geometrical descriptors quantifying three-dimensional aspects of molecular structure, which indicates that the molecular three-dimensional conformation is of high significance for the MARSplines modeling procedure and obviously for FXa inhibitory activity. High model performance was confirmed through an extensive validation protocol. The results of the study not only confirmed the enhancement in pharmacological activity by the presence of chlorine in a phenyl ring, but also, and primarily, may provide the basis for searching for new active isosteviol analogues, which may serve as drugs or health-beneficial food additives in patients suffering from obesity and comorbidities.

Application of Multivariate Adaptive Regression Splines (MARSplines) for Predicting Antitumor Activity of Anthrapyrazole Derivatives.

An approach using multivariate adaptive regression splines (MARSplines) was applied for quantitative structure-activity relationship studies of the antitumor activity of anthrapyrazoles. At the first stage, the structures of anthrapyrazole derivatives were subjected to geometrical optimization by the AM1 method using the Polak-Ribiere algorithm. In the next step, a data set of 73 compounds was coded over 2500 calculated molecular descriptors. It was shown that fourteen independent variables appearing in the statistically significant MARS model (i.e., descriptors belonging to 3D-MoRSE, 2D autocorrelations, GETAWAY, burden eigenvalues and RDF descriptors), significantly affect the antitumor activity of anthrapyrazole compounds. The study confirmed the benefit of using a modern machine learning algorithm, since the high predictive power of the obtained model had proven to be useful for the prediction of antitumor activity against murine leukemia L1210. It could certainly be considered as a tool for predicting activity against other cancer cell lines.

Recent Applications of Capillary Electrophoresis in the Determination of Active Compounds in Medicinal Plants and Pharmaceutical Formulations.

The present review summarizes scientific reports from between 2010 and 2019 on the use of capillary electrophoresis to quantify active constituents (i.e., phenolic compounds, coumarins, protoberberines, curcuminoids, iridoid glycosides, alkaloids, triterpene acids) in medicinal plants and herbal formulations. The present literature review is founded on PRISMA guidelines and selection criteria were formulated on the basis of PICOS (Population, Intervention, Comparison, Outcome, Study type). The scrutiny reveals capillary electrophoresis with ultraviolet detection as the most frequently used capillary electromigration technique for the selective separation and quantification of bioactive compounds. For the purpose of improvement of resolution and sensitivity, other detection methods are used (including mass spectrometry), modifiers to the background electrolyte are introduced and different extraction as well as pre-concentration techniques are employed. In conclusion, capillary electrophoresis is a powerful tool and for given applications it is comparable to high performance liquid chromatography. Short time of execution, high efficiency, versatility in separation modes and low consumption of solvents and sample make capillary electrophoresis an attractive and eco-friendly alternative to more expensive methods for the quality control of drugs or raw plant material without any relevant decrease in sensitivity.

Serum amino acid profiles in patients with mild cognitive impairment and in patients with mild dementia or moderate dementia.

Neurodegenerative disorders are one of the greatest global challenges for social and health care in the twenty-first century. Nowadays, determination of cerebrospinal fluid biomarkers for early diagnosis is served by a complex sample preparation procedure with limited diagnostic accuracy. Furthermore, neuroimaging methods are expensive, time-consuming and are not readily available for use as a complimentary and common screening method. Recently, researchers have shown an increased interest in the identification and characterization of new blood biomarkers of dementia to minimize the limitations associated with the current methods of biomarker determination. Amino acids play many important roles in the central nervous system, acting as neuromodulators, neurotransmitters and regulators of energy metabolism. The aim of this study was to evaluate if serum amino acid levels change along the continuum from no cognitive impairment to moderate dementia, and to identify putative biomarkers for early diagnosis of neurodegenerative diseases. Serum levels of 16 amino acids were determined in 3 groups of patients-22 with mild cognitive impairment, 45 with mild dementia and 28 with moderate dementia-by high-performance liquid chromatography (HPLC) with fluorescence detection using AccQ Tag column (Waters). The most exciting result is the significantly elevated concentration of arginine in patients with both stages of dementia as compared to mild cognitive impairment individuals. Recent accumulating evidence suggests the implication of changed arginine metabolism in the pathogenesis of neurodegenerative diseases. We conclude that amino acids profiling might be helpful in searching for biomarkers of neurogenerative diseases. In the present study, we discovered that arginine in plasma may have a putative diagnostic value for dementia.

Amino Acid Levels as Potential Biomarker of Elderly Patients with Dementia.

Dementia is a clinical syndrome characterized by cognitive impairment, in which there is disturbance of multiple higher cortical functions. The primary risk factor of dementia is old age, and due to significant changes in the worldwide demographic structure, the prevalence of cognitive impairment is increasing dramatically with aging populations in most countries. Alzheimer's disease is the predominant and leading cause of dementia. The aim of this study was to evaluate the modifications of amino acids that characterize the initial stages of dementia to help our understanding of the complex and multifactorial pathogenesis of neurodegenerative disorders. A total of 123 participants were divided into two groups: healthy elderly subjects and patients with mild or moderate dementia. The results of this study indicate that the serum levels of three amino acids were changed significantly in patients with dementia, in relation to the subjects without dementia. In particular, we observed differences in concentrations for serine, arginine and isoleucine (all of them were significantly increased in patients with dementia, compared with the control group). Our results suggest that the metabolisms of some amino acids seem be changed in patients with dementia. We conclude that amino acid profiling might be helpful for the better understanding of biochemical and metabolic changes related to the pathogenesis and progression of dementia. However, considering the multifactorial, heterogenous and complex nature of this disease, validation with a greater study sample in further research is required.

Comparison of Pteridine Normalization Methods in Urine for Detection of Bladder Cancer.

Pterin compounds belong to the group of biomarkers for which an increase in interest has been observed in recent years. Available literature data point to this group of compounds as potential biomarkers for cancer detection, although the biochemical justification for this claim is not yet fully understood. The aim of this study was to evaluate the usefulness of pterin compounds in the diagnosis of bladder cancer, with particular emphasis on the role of creatinine and the specific gravity of urine as factors for normalizing the concentration of pterin compounds in urine. The standardization of the concentration of pterin compounds to urine specific gravity allows the building of better classification models for screening patients with potential cancer of the bladder. Of the compounds that make up the pterin profile, isoxanthopterin appears to be a compound that can potentially be described as a biomarker of bladder cancer.

Comparison of high-performance thin layer chromatography/UV-densitometry and UV-derivative spectrophotometry for the determination of trimetazidine in pharmaceutical formulations.

New methods for assaying trimetazidine dihydrochloride on the basis of thin layer chromatography and spectrophotometry are proposed and compared in the paper. In HPTLC/UV-densitometry, separation is achieved by using a mobile phase composed of ammonia-methanol (30:70, V/V) on silica gel HPTLC plates F254. Quantification using a non-linear calibration curve is accomplished by densito-metric detection at 230 nm. Derivative spectrophotometric determination of trimetazidine dihydrochloride is carried out from the fourth derivative of the absorbance at 233 nm in peak-zero mode. Statistical comparison led to the conclusion that there is no significant difference between the two studied methods and, moreover, that they demonstrate satisfactory accuracy and precision for routine applications.

Effects of 3-months sitting callisthenic balance and resistance exercise on aerobic capacity, aortic stiffness and body composition in healthy older participants. Randomized Controlled Trial.

BACKGROUND: Arterial stiffness (AS) is a reduction in the ability of large arteries to readily accommodate the increase in blood ejected from the heart during systole related with aging. Physical exercise is associated with AS reduction. However, it remains controversial as to which modality and intensity (resistance vs aerobic, high vs low) would be the most effective. The aim of these studies is to examine the effects of 3-months sitting callisthenic balance (SCB) and resistance exercise (RET) on aerobic capacity, aortic stiffness and body composition in older participants. MATERIAL AND METHODS: Aortic pulse wave velocity (PWVao), return time (RT), diastolic reflection area (DRA) and blood pressure (BP) level changes were measured with Arteriograph. Aerobic capacity was examined with 6-min walk test (6-MWT) and spiroergometry (VO2max). Body composition was analyzed by Bioelectric Impedance Analysis using Tanita. RESULTS: Significant improvements of BP, PWVao, RT and DRA were observed in the SCB group (p = 0.018, p = 0.017 and p = 0.012, respectively). % of fat mass improved in RET and SCB group (p = 0.003, p = 0.012, respectively). Visceral fat significantly improved in SCB group (p = 0.03). CONCLUSIONS: Despite no significant changes in indicators of aerobic capacity (VO2max and 6MWT result) in both groups, significant improvement in all measures of AS, except SBPao were observed in the SCB group, while no AS improvement in the RET group was noted. There were some differences in pattern of body compositions improvement between two groups.