Tacrolimus and Azole Derivatives of Agricultural and Human Health Importance: Prediction of ADME Properties

INTRODUCTION

Agricultural chemicals are impacting health nowadays. Recently, promising synergistic antifungal interaction between tacrolimus and some azole compounds was studied.

OBJECTIVE

To determine ADME parameters, potential side effects of test substances to reduce time and resources in the future.

METHODS

All descriptors and molecular parameters were obtained by the protocols of SwissADME and ProTox II.

RESULTS

In the result, the following physicochemical and drug-likeness parameters were calculated.

CONCLUSION

Studied triazoles 1 and 2 showed good ADME characteristics and promising toxicity levels suitable to be checked for in vitro toxicology in case of future advanced results in the agricultural field.

LC-MS/MS bioanalytical method for the quantitative analysis of nifedipine, bisoprolol, and captopril in human plasma: Application to pharmacokinetic studies

In this study, the development and validation of an accurate and highly sensitive LC-MS/MS method were performed for the estimation of nifedipine, bisoprolol and captopril in real human plasma. Liquid-liquid extraction using tert-butyl methyl ether was efficiently applied for extraction of the analytes from plasma samples. The chromatographic separation was carried out using an isocratic elution mode on the X-terra MS C18 column (4.6 × 50 mm, 3.5 μm). The mobile phase consisted of methanol-0.1% formic acid (95:5, v/v) for determination of nifedipine and bisoprolol and acetonitrile-0.1% formic acid (70:30, v/v) for determination of captopril with a flow rate of 0.5 ml/min. Acceptable results regarding the different validation characteristics of the analytes were obtained in accordance with US Food and Drug Administration recommendations for bioanalytical methods. The developed approach was linear over concentration ranges of 0.5-130.0, 50.0-4,500.0 and 0.3-30.0 ng/ml for nifedipine, captopril and bisoprolol, respectively. The method revealed a sufficient lower limit of quantification in the range of 0.3-50.0 ng/ml, as well as high recovery percentages, indicating high bioanalytical applicability. The proposed method was efficiently applied to a pharmacokinetic evaluation of a fixed-dose combination of the analytes in healthy male volunteers.

Observation of Collider Muon Neutrinos with the SND@LHC Experiment

We report the direct observation of muon neutrino interactions with the SND@LHC detector at the Large Hadron Collider. A dataset of proton-proton collisions at sqrt[s]=13.6  TeV collected by SND@LHC in 2022 is used, corresponding to an integrated luminosity of 36.8  fb^{-1}. The search is based on information from the active electronic components of the SND@LHC detector, which covers the pseudorapidity region of 7.2<η<8.4, inaccessible to the other experiments at the collider. Muon neutrino candidates are identified through their charged-current interaction topology, with a track propagating through the entire length of the muon detector. After selection cuts, 8 ν_{μ} interaction candidate events remain with an estimated background of 0.086 events, yielding a significance of about 7 standard deviations for the observed ν_{μ} signal.

5,6-Dihydrotetrazolo[1,5-c]quinazolines: Toxicity prediction, synthesis, antimicrobial activity, molecular docking, and perspectives

Antimicrobial resistance is a never-ending challenge, which should be considered seriously, especially when using unprescribed "over-the-counter" drugs. The synthesis and investigation of novel biologically active substances is among the directions to overcome this problem. Hence, 18 novel 5,6-dihydrotetrazolo[1,5-c]quinazolines were synthesized, their identity, purity, and structure were elucidated by elemental analysis, IR, LC-MS, ¹ Н, and ¹³ C NMR spectra. According to the computational estimation, 15 substances were found to be of toxicity Class V, two of Class IV, and only one of Class II. The in vitro serial dilution method of antimicrobial screening against Escherichia coli, Staphylococcus aureus, Klebsiella aerogenes, Pseudomonas aeruginosa, and Candida albicans determined b3, c1, c6, and c10 as the "lead-compounds" for further modifications to increase the level of activity. Substance b3 demonstrated antibacterial activity that can be related to the calculated high affinity toward all studied proteins: 50S ribosomal protein L19 (PDB ID: 6WQN), sterol 14-alpha demethylase (PDB ID: 5TZ1), and ras-related protein Rab-9A (PDB ID: 1WMS). The structure-activity and structure-target affinity relationships are discussed. The targets for further investigations and the anatomical therapeutic chemical codes of drug similarity are predicted.

Substituted acyl thioureas and acyl thiosemicarbazides: synthesis and biological activity (minireview)

Acyl isothiocyanates and their functional derivatives (acyl thioureas and acyl thiosemicarbazides) are an important group of organic compounds that are widely used in the synthesis of heterocycles and in chemistry as catalysts, ligands, colorimetric hemosensors, etc. In recent years, there has been an increased interest towards this class of compounds as promising biologically active compounds, especially since the latest advances in medicinal chemistry for them are not sufficiently studied. The aim. To summarize and systematize information for the last 10 years on methods of synthesis and biological activity of substituted acyl thioureas and acyl thiosemicarbazides. Materials and methods. Web-tools for finding scientific information (Reaxys, Scopus, Google Scholar, ScienceResearch, SciFinder, Web of Science, etc.). Results and discussion. Literature sources related to the methods of synthesis of substituted acyl thioureas and acyl thiosemicarbazides were systematized and analyzed. The main approaches for the formation of these compounds are revealed: stepwise formation from carboxylic acids, through acyl chlorides and acyl isothiocyanates followed by nucleophilic addition of amines or hydrazides of carboxylic acids ("one-pot synthesis"), nucleophilic addition of amines or hydrazides of carboxylic acids directly to acyl isothiocyanates and parallel microwave synthesis using acyl isothiocyanates and amines as reagents. The possibility of their use as ligands for the formation of complex compounds with transition metal ions was discussed. In the review biological activity of these structures, namely antimicrobial, fungicidal, antitumor, antiviral, antifungal and other activities was detailazed. Conclusions. The basic approaches to the synthesis of substituted acylthuoureas and acyl thiosemicarbazides which include the application of carboxylic acids, their derivatives (acyl halides and isothiocyanates) and N-nucleophiles as initial compounds were discussed. It was shown that aforementioned class of the compounds reveals the versatile biological activity and are promising for further structural modification aimed to the search of novel drugs

Synthesis and anticonvulsant activity evaluation of n-[(2,4-dichlorophenyl)methyl]-2-(2,4-dioxo-1h-quinazolin-3-yl)acetamide novel 1-benzylsubstituted derivatives

The aim. Synthesis of 1-benzylsubstituted derivatives of N-[(2,4-dichlorophenyl)methyl]-2-(2,4-dioxo-1h-quinazolin-3-yl)acetamide, and determination of affinity to GABAergic biotargets with the following anticonvulsant activity estimation using PTZ-induced seizures model in mice. Materials and methods. Standard organic synthesis methods were used; the structure of the synthesized compounds was proved by elemental analysis, 1H and 13C NMR spectroscopy, and LC/MS method; composition of the synthesized compounds – by elemental analysis, their individuality – by TLC and LC/MS methods. AutoDockTools-1.5.6, as well as AutoDock Vina software, was used to perform molecular docking. Anticonvulsant activity was studied using pentylenetetrazole-induced seizures in mice. Results. A targeted N-[(2,4-dichlorophenyl)methyl]-2-(1-(R-benzyl)-2,4-dioxo-quinazolin-3-yl)acetamides were obtained by alkylation of N-[(2,4-dichlorophenyl)methyl]-2-(2,4-dioxo-1H-quinazolin-3-yl)acetamide by corresponding 1-chloromethylbenzene in dimethylformamide environment with excess of potassium carbonate at a temperature 70-80 ˚С. Prediction of activity of 1-benzyl derivatives in the pentylenetetrazole-induced seizures in an in vivo experiment was carried out according to the obtained results of docking studies – affinity calculation for GABA receptor and GABA enzyme active sites, as well as analysis of conformational placement in them. In relation to the binding energy, the studied ligands were inferior to the reference drugs: GABA receptor positive allosteric modulators – benzamidine and diazepam, and GABA inhibitor – vigabatrin. The synthesized substances did not show anticonvulsant activity: only 2 compounds have shown a tendency to their activity manifestation according to the criterion of integral protective indicator – reduction of mortality by 17 % compared to control, as well as prolonging the time death of the animals. Comparison with the preliminary obtained results of the activity of the promising anticonvulsant N-[(2,4-dichlorophenyl)methyl] -2-(2,4-dioxo-1H-quinazolin-3-yl) acetamide N-[(2,4-dichlorophenyl)methyl]-2-(2,4-dioxo-1H-quinazolin-3-yl)acetamide made possible to prove the pharmacophore role of the cyclic amide fragment in anticonvulsant activity manifestation. Conclusion. The synthesis of N-[(2,4-dichlorophenyl)methyl]-2-(1-(R-benzyl)-2,4-dioxo-quinazolin-3-yl)acetamides, which have not still described in the literature, was carried out, as well as the structure of the mentioned compounds was proved. Unfortunately, the substances did not show anticonvulsant activity on the model of pentylenetetrazole-induced seizures. However, the obtained results allowed establishing the key role of the NHCO cyclic fragment on anticonvulsant activity. A positive correlation between the results of in vivo studies and in silico calculations was found – the model of pentylenetetrazole-induced seizures and docking into the active sites of PAMs GABAА receptor and enzyme inhibitor GABAАТ, which allows to recommend the given docking methodology as a tool to streamline and optimize the screening on the mentioned model

Chromato-mass-spectrometric research in Salvia grandiflora L., Salvia pratensis L. and Salvia verticillata L. aboveground organs

The genus Salvia L. has more than 900 species distributed throughout the globe. 21 species are growing in Ukraine. All species of this genus have essential oils. Salvia officinalis and Salvia sclarea have been used in the culture and are widely used in medical practice. The chemical composition of other species of sage and the possibility of their use in pharmaceutical and medical practice are almost not studied. Taking into account the results of chemotaxonomic studies of species of the flora genus of Ukraine, their prevalence and prospects for introduction into the culture, for further studies were selected raw materials of S. grandiflora, S. pratensis and S. verticillata. The aim. The aim of the study was to conduct a chromato-mass spectrometric study of the aboveground organs of S. grandiflora L., S. pratensis L. and S. verticillata L. to establish the prospects for the use of raw materials of these species in medical and pharmaceutical practice. Materials and methods. The objects of the study were leaves of S. officinalis, leaves, stems and flowers of S. grandiflora, S. pratensis and S. verticillata, which were harvested on the basis of the botanical garden of Ivan Franko National University of Lviv. The research of volatile substances in the objects of the research was carried out by the method of GC-MS on the basis of the Department of Natural Sciences for Foreign Students and Toxicological Chemistry of Zaporizhia State Medical University. Results. As a result of the study, 243 substances were found in the objects of the study, of which 149 were identified. 77 substances were found in the leaves of S. officinalis, 80, 26 and 63 substances in the leaves, stems and flowers of S. grandiflora, respectively, in the leaves , stems and flowers of S. pratensis – 28, 30 and 48 substances, respectively, in leaves, stems and flowers of S. verticillata – 39, 22 and 39 substances, respectively. Dominant compounds among substances of terpenoid nature are: cyclofenchene, camphene, 1,8-cineole, α-thujone, β-thujone, camphor borneol, caryophyllene, humulene, viridiflorol, sabinene, pyranone, β-pinene, phytol, kolavenol, β-copaen, loliolide, pseudolimonene and spatulenol. Among the dominant substances, 8 were detected for the first time in these species: cyclofenchene, viridiflorol, sabinene, pyranone, phytol, kolavenol, loliolide and pseudolimonene. Conclusions. The leaves of S. officinalis, leaves, stems and flowers of S. grandiflora, S. pratensis and S. verticillata of the flora of Ukraine were studied by chromato-mass spectrometric method. As a result of the study, 243 substances were identified, of which 149 were identified. Promising raw materials containing terpene compounds for S. grandiflora there are leaves, and for S. pratensis and S. verticillata – flowers, so they are promising agents for introduction into pharmaceutical practice

Research in phytochemical composition and hypoglycemic activity screening of the dry extracts from bearberry leaves

Diabetes mellitus is a global medical and social issue. In the developed countries of the world, from 5 to 12% of the population are diagnosed with diabetes mellitus and, according to WHO prognosis, the level of this disease may increase to 30-35%. Type 2 diabetes is a disease that progresses over time, but the rational and systematic use of hypoglycemic synthetic drugs and phytopreparations can significantly delay the onset of insulin therapy. A promising source of BAS with a hypoglycemic effect is the raw material of plants of the Heather family, namely, bearberry leaves. However, on the Ukrainian market there are no domestic galenic and novo-galenic preparations based on biologically active substances of this raw material, which indicates the prospects for the development of new drugs, including those with hypoglycemic action. The aim. The aim of the study was to study the phytochemical composition and to carry out a screening of the hypoglycemic activity of dry extracts from bearberry leaves modified with various amino acids to identify promising substances with hypoglycemic action. Materials and methods. The objects of the study were 11 dry extracts from bearberry leaves, 10 of which were modified with various amino acids. The study of the phenolic compounds of the extracts was carried out by TLC, HPLC, and spectrophotometry. To assess the hypoglycemic activity of the extracts, two experiments were carried out - primary screening and oral glucose tolerance test. Results. Using TLC and HPLC, in the extracts obtained arbutin, gallic acid, 5 flavonoids were identified, among which hyperoside was dominant, 4 hydroxycinnamic acids, among which chlorogenic and caffeic acids were dominant, and their content was established. In the extracts obtained, main groups of phenolic compounds were quantified using a spectrophotometric method. Dry extracts from bearberry leaves, modified with cysteine, arginine and glutamic acid, showed the strongest hypoglycemic activity. Conclusions. The chemical composition of phenolic compounds and the hypoglycemic activity of dry extracts from bearberry leaves modified with 10 different amino acids were determined. The most promising substances turned out to be extracts modified with cysteine, arginine and glutamic acid; therefore, they are promising agents for the development of new drugs.

Chaotropic salts impact in HPLC approaches for simultaneous analysis of hydrophilic and lipophilic drugs

Simultaneous determination of drugs with different physicochemical properties necessitates thorough research and careful selection of high-performance liquid chromatography conditions. In the present study, various concepts of high-performance liquid chromatography method development for this aim have been discussed. Moreover, the work was motivated by the advantages of utilizing different chaotropic anions as a new promising approach to overcome the limitations of ion-pairing agents commonly used for this purpose. Based on log P values, atorvastatin (log P = 6.36) and lisinopril (log P = -1.22) were chosen as representative examples for lipophilic and hydrophilic drugs, respectively. Several simple, economic, fast, and reliable high-performance liquid chromatography methods were developed for their simultaneous analysis and are presented in a comparative manner, highlighting their advantages and limitations. Peak elution profile showed satisfying retentions and resolution about 3. Photo-diode array calculations were exploited for identifying the molecules by their ultra-violet spectra and peak purity, calculated and presented as rectangular-shaped ratio grams. The linearity check showed excellent results and satisfactory system suitability parameters of both peaks. This confirms the investigation results and conclusions for the influence of the chaotropic salts on N-containing molecules, by increasing their retentivities, and improving peak shapes, even on different quality columns without end-capping and base-deactivating of separation matrixes.

Method development for the quantitative determination of captopril from Caco-2 cell monolayers by using LC-MS/MS

Aim. Caco-2 cells are a human colon epithelial cancer cell line used as a model of human intestinal absorption of drugs and other compounds. Although compounds were used in the original Caco-2 cells monolayer assays, compounds have been replaced in most laboratories by the use of liquid chromatography-mass spectrometry (LC-MS) and LC-tandem mass spectrometry (LC-MS/MS). Mass spectrometry not only eliminates the need for compounds, but permits the simultaneous measurement of multiple compounds. The measurement of multiple compounds per assay reduces the number of incubations that need to be carried out, thereby increasing the throughput of the experiments. Furthermore, LC-MS and LC-MS-MS add another dimension to Caco-2 assays by facilitating the investigation of the metabolism of compounds by Caco-2 cells. A simple, rapid LC-MS/MS method has been developed for determination of captopril from confluent Caco-2 monolayers and from aqueous solution.

Materials and methods. Chromatography was achieved on Discovery C18, 50 × 2.1 mm, 5 μm column. Samples were chromatographed in a gradient mode (eluent A (acetonitrile – water – formic acid, 5 : 95 : 0.1 v/v), eluent B (acetonitrile – formic acid, 100 : 0.1 v/v)). The initial content of the eluent B is 0%, which increases linearly by 1.0 min to 100% and to 1.01 min returns to the initial 0%. The mobile phase was delivered at a flow rate of 0.4 mL/min into the mass spectrometer ESI chamber. The sample volume was 5 μl.

Results. Under these conditions, captopril was eluted at 1.42 min. A linear response function was established at 2 – 200 ng/mL. The regression equation for the analysis was y =0.0187x+0.000248 with coefficient of correction (r2) = 0.9993. According to the Caco-2 test results, captopril showed low permeability. It should be noted that the recovery value is 103.20%. The within-run coefficients of variation ranged between 0.321% and 0.541%. The within-run percentages of nominal concentrations ranged between 99.13% and 101.12%. The between-run coefficients of variation ranged between 0.314% and 0.663%. The between-run percentages of nominal concentrations ranged between 99.17% and 101.03%.The assay values on both the occasions (intra- and inter-day) were found to be within the accepted limits.

Conclusion. From results of analysis, it can be concluded that developed method is simple and rapid for determination of captopril from confluent Caco-2 monolayers and from aqueous solution. Acquired results demonstrate that proposed strategy can be effortlessly and advantageously applied for examination of captopril from Caco-2 cell monolayers.

Quality by design approach for simultaneous determination of original active pharmaceutical ingredient quinabut and its impurities by using HPLC. Message 1

Aim. The aim of study was to develop and validate a simple, highly robust (quality by design (QbD) approach), precise and accurate method using high performance liquid chromatography for the simultaneous determination of original active pharmaceutical ingredient Quinabut and its impurities.

Materials and methods. Experiments were performed on a Shimadzu LC-20 Prominence HPLC separation module, equipped with a quaternary gradient pump, temperature controlled column heater, sampler manager and diode array detector and LC-20 Chemstation for data analysis (Shimadzu Corporation, Japan). Same software was used for data acquisition and processing of results. X-Terra RP18 (4.6×150 mm, 5 μm) analytical chromatographic column provided by Waters Corporation (Milford, MA) was used for all optimization experiments. Mobile phase A: acetonitrile R. Mobile phase B: 0.025 M phosphate buffer solution. Samples were chromatographed in gradient mode. Flow rate of the mobile phase: 0.7 mL/min. Column temperature: 40 °С. Detection: at 233 nm wavelength. Injection volume: 50 μl.

Results. Screening of the influence of four chromatographic factors on different chromatographic responses was performed as the initial step of analytical method optimization. A randomized fractional factorial experimental design (24–1) of resolution IV with central point was used. Buffer pH, amount of acetonitrile in mobile phase A, the amount of phosphate buffer solution in mobile phase B and column temperature were selected as factors of interest, and were used to generate the fractional factorial experimental design. Linearity was established in the range of LOQ level to 0.2% having regression coefficients 0.9977. Calibration curve – y = 0.0132 + 0.9902. Since Δt for the content of quinabut is less than max δ, the technique is stable over time. The possibility of contamination of the sample by decomposition products by keeping it under stressful conditions (irradiation of the substance solution with UV light (UV irradiation with mercury lamp light); acid hydrolysis with 0.1 M hydrochloric acid solution; oxidative decomposition) was investigated. As a result of the irradiation with UV light, the impurity peaks for about 8.74 min (impurity C) and 12.68 min (impurity B) are additionally revealed. Their content exceeds the limits of normalization and is 0.6% and 3.7%, respectively. Therefore, the powder of the substance and its solutions should be stored away from direct sunlight. The column temperature and the speed of the mobile phase within ± 10% did not significantly affect the test results. The results were found to be within the assay variability limits during the entire process.

Conclusion. 1) The optimization of a new analytical method capable of simultaneous determination of quinabut assay and its impurities drug products was performed with a single fractional factorial experimental design. Only 11 experiments were needed for the optimization, while at least 16 experiments would be needed to cover the same analytical method operational region of the first optimization step with a traditional one factor at time (OFAT) approach. 2) HPLC method was developed and validated for the simultaneous detection and quantitation of quinabut and its impurities. 3) The final analytical method optimized with QbD approach was validated according to ICHQ2R1 guideline. The method proved to be sensitive, selective, precise, linear, accurate and stability-indicating. 4) The method was successfully applied to the analysis of demonstrating acceptable precision and adequate sensitivity for the detection and quantitation of quinabut and its impurities. So it may be reasonable to claim that the method can be extended to the analysis of drug formulations and stability samples as well. This optimization reflects in saving of time and resources since one stability study includes hundreds of samples tested during the product’s shelf life.

Method development and validation for the determination of residual solvents in quinabut API by using gas chromatography. Message 2

Aim. The aim of study was to develop and validate a simple, precise and accurate method using gas chromatography for analysis of residual solvents – acetone and 2-propanol – in quinabut API.

Materials and methods. All experiments were performed on a gas chromatographic system equipped with FID detector (Shimadzu GC System) using the DB-624 (30 m × 0.32 mm ID, 3.0 μm film sickness) column as stationary phase. Nitrogen was used as carrier gas with flow rate 7.5 mL/ min. Split ratio was 1:5, injector temperature was 140 °C, detector temperature was 250 °C, oven temperature was programmed from 40 °C (2 min) to 50 °C at 1 °C/min and then increased at a rate of 15 °C/min up to 215 °C; and maintained for 2 min. All solutions were prepared using water as diluent.

Results. This proposed method is assessed for separation of residual solvent from quinabut with quantification. The obtained results are compared with the corresponding specified limits of ICH standard guidelines. The method validation was done by evaluating specificity, limit of detection (LOD) and limit of quantitation (LOQ), linearity, accuracy, repeatability, ruggedness, system suitability and method precision of residual solvents as indicated in the ICH harmonized tripartite guideline. The separation between acetone and 2-propanol peaks is 2.07. Hence method was found to be specific. The linear relationship evaluated across range of 15 to 180% for acetone and 2-propanol of ICH specified limit of residual solvents. The graphs of theoretical concentration versus obtained concentration are linear and the regression coefficients ‘R’ for residual solvents were more than 0.9968. The values of LOD and LOQ were much less than the lower limit of the concentration range and cannot affect the accuracy of the test. The technique was characterized by high intra-laboratory accuracy at concentrations close to the nominal acetone and 2-propanol concentration. All solutions were stable in water for at least 1 hour when stored at room temperature.

Conclusion. A simple, specific, accurate, precise and rugged gas chromatography method was developed and validated for the quantification of residual solvents present in quinabut API through an understanding of the synthetic process, nature of solvents and nature of stationary phases of columns. The residual solvents acetone and 2-propanol were determined.

Substituted 3-R-2,8-Dioxo-7,8-dihydro-2H-pyrrolo[1,2-a][1,2,4] triazino [2,3-c]quinazoline-5a(6H)carboxylic Acids and their Salts - a Promising Class of Anti-inflammatory Agents

BACKGROUND

Computer-aided drug design is among the most effective methods of medicinal chemistry. The above mentioned approach is used for the purposeful search of antiinflammatory agents among quinazoline condensed derivatives.

OBJECTIVE

The study aimed to conduct a purposeful synthesis of novel 3-R-2,8-dioxo-7,8-dihydro- 2H-pyrrolo[1,2-a][1,2,4]triazino[2,3-c]quinazoline-5a(6H)carboxylic acids and their salts as promising anti-inflammatory agents, evaluate their structure by physicochemical methods and establish their anti-inflammatory activity.

METHODS

The structures of target compounds were proposed due to their structure similarity to existing drugs and experimental agents with anti-inflammatory activities. The features of the synthesized compounds structures were evaluated by IR-, NMR spectroscopy and chromatography-mass spectrometry and discussed in detail. Probable molecular mechanisms of activity were predicted by molecular docking. The anti-inflammatory activity was determined by their ability to reduce the formalin- and carrageenan-induced paw edema in rats.

RESULTS

It was found that the condensation of 3-(2-aminophenyl)-6-R-1,2,4-triazin-5(2H)ones with 2-oxoglutaric acid yielded 3-R-2,8-dioxo-7,8-dihydro-2H-pyrrolo[1,2-a][1,2,4]triazino[2,3-c]quinazoline- 5a(6H)carboxylic acids which may be considered as a promising anti-inflammatory agent. An in silico study showed that the obtained compounds revealed affinity to the molecular targets and corresponded to the drug-like criteria. Additionally docking study allowed to estimate the nature of interactions between synthesized compounds and molecular targets. The in vivo experiments showed that the obtained compounds demonstrated significant anti-inflammatory activity comparable or higher than the activity of the reference drug Diclofenac.

CONCLUSION

The developed and implemented search strategy of the anti-inflammatory agents was justified. 3-R-2,8-dioxo-7,8-dihydro-2H-pyrrolo[1,2-a][1,2,4]triazino[2,3-c]quinazoline5a(6H)carboxylic acids possessed the anti-inflammatory activity and additional introduction of fluorine atoms in position 11 or 12 of the heterocyclic system led to amplification of this activity.

Synthesis and mode of action studies of novel {2-(3-R-1H-1,2,4-triazol-5-yl)phenyl}amines to combat pathogenic fungi

Due to their high specificity and efficacy, triazoles have become versatile antifungals to treat fungal infections in human healthcare and to control phytopathogenic fungi in agriculture. However, azole resistance is an emerging problem affecting human health as well as food security. Here we describe the synthesis of 10 novel {2-(3-R-1H-1,2,4-triazol-5-yl)phenyl}amines. Their structure was ascertained by liquid chromatography-mass spectrometry, ¹ H and ¹³ C NMR, and elemental analysis data. Applying an in vitro growth assay, these triazoles show moderate to significant antifungal activity against the opportunistic pathogen Aspergillus niger, 12 fungi (Fusarium oxysporum, Fusarium fujikuroi, Colletotrichum higginsianum, Gaeumannomyces graminis, Colletotrichum coccodes, Claviceps purpurea, Alternaria alternata, Mucor indicus, Fusarium graminearum, Verticillium lecanii, Botrytis cinerea, Penicillium digitatum) and three oomycetes (Phytophtora infestans GL-1, P. infestans 4/91; R+ and 4/91; R-) in the concentration range from 1 to 50 µg/ml (0.003-2.1 μM). Frontier molecular orbital energies were determined to predict their genotoxic potential. Molecular docking calculations taking into account six common fungal enzymes point to 14α-demethylase (CYP51) and N-myristoyltransferase as the most probable fungal targets. With respect to effectiveness, structure-activity calculations revealed the strong enhancing impact of adamantyl residues. The shown nonmutagenicity in the Salmonella reverse-mutagenicity assay and no violations of drug-likeness parameters suggest the good bioavailability and attractive ecotoxicological profile of the studied triazoles.

EXPERIMENTAL STUDY OF PAIN-RELIEVING MECHANISMS OF 4-[4-OXO-(4H)-QUINAZOLIN-3-YL]-BENZOIC ACID (PK-66 COMPOUND)

An in-depth study of the pharmacological properties of 4-[4-oxo-(4h)-quinazolin-3-yl]-benzoic acid as an analgesic agent established that it had a sufficiently high analgesic effect on models of somatic and neuropathic pain syndromes. Study objective was to study the mechanisms of analgesic action of PK-66 compound in rats using the pharmacological analysis. We evaluated the mechanisms of analgesic effect of PK-66 (1 mg/kg, intraperitoneal) compound on the thermal irritation model on Hours 1, 2, 4 and 6 after administration of study compounds. To evaluate the mechanisms of PK-66 compound pain killing, we determined the changes in its efficacy against the effects of pharmacological analyzers - Naloxon, Tramadolum, Clophelinum (Clonidine), Yohimbine, Noraepinephrine, Reserpinum, Chlorpromazine (Aminazin), Levodopa, Diazepam, and Memantine). The anti-nociceptive effect of PK-66 compound was virtually unchanged during all study terms with underlying administration of Naloxon, an opioid receptor antagonist. The results of administration of Reserpinum in rats and the concomitant administration of Noradrenaline, Clophelinum, Yohimbine and quinazoline derivative demonstrated that the adrenergic system, in particular alpha-2 adrenergic receptors, was involved in the mechanisms of PK-66 activity. Changes in the PK-66 compound effect with underlying previous administration of Levodopa and Chlorpromazine suggested that the dopaminergic system was unquestionably involved in the analgesic activity of the compound. Further study of the involvement of inhibitory and exhilarating amino acids, GABA and glutamate, showed that administration of Diazepam potentiated and extended the PK-66 analgesic effect on the thermal nociception models throughout the experiment. At the same time, increased antinociception with underlying Memantine administration preceding PK-66 was observed only in the first hours of the experiment. Therefore, the studies conducted have shown that the adrenergic system, in particular alpha-2 adrenergic receptors, dopaminergic and GABAergic systems, is involved in the mechanisms of analgesic action of 4-[4-oxo-(4h) -quinazolin-3-yl]-benzoic acid (PK-66) without any effect of PK-66 on opioid receptors.

SYNTHESIS OF THE NEW 2-(3,4-DIHYDRO-3-OXO-2H-[1,2,4]TRIAZINO[4,3-C]QUINAZOLIN-4-YL) ACETIC ACID DERIVATIVES AND ANALYSIS OF THEIR ANTIOXIDANT ACTIVITY IN NITROSATIVE STRESS MODELS

Today we know that NO· and ONOO- are clue pathophysiological factors for progression some ischemic diseases of the central nervous system. So investigation of the antioxidants which will be able to decrease NO· and ONOO- toxicity seems to be very of current interest. The six esters and three amides of 2-(3,4-dihydro-3-oxo-2H-[1,2,4]triazino[4,3-c]quinazolin-4-yl)acetic acid were synthesized for this study, and we showed evidence of antioxidant activity of these new original derivatives. We studied the effect of 2-(3,4-dihydro-3-oxo-2H-[1,2,4]triazino[4,3-c]quinazolin-4-yl)acetic acid derivatives on superoxide dismutase activity under the condition of excessive NO· and ONOO- production. NO· induction was performed by the action of light on sodium nitroprusside Na2[Fe(NO)(CN)5]×2H2O in vitro. Also, the investigation of the substances was carried out in the brain supernatant obtained from the white Wistar rats in vivo. For nitrosative stress modeling dinitrozolic complex of Fe2+ and cysteine were utilized. Our data showed that 2-(3,4-dihydro-3-oxo-2H-[1,2,4]triazino[4,3-c]quinazolin-4-yl)acetic acid is not active compound while its esters and amides have antioxidant activity. Compound benzyl ester of this acid revealed the most effective antioxidant activity.

Design, Synthesis and Anti-inflammatory Activity of Derivatives 10-R-3-Aryl-6,7-dihydro-2H-[1,2,4] triazino[2,3-c]quinazolin-2-ones of Spiro-fused Cyclic Frameworks

Present work is devoted to the purposeful search of novel promising anti-inflammatory agents among the insufficiently known 3'-R-10'-R1-spiro[hetaryl-3(4),6'-[1,2,4]triazino[2,3-c]quinazolin]-2'(7'H)-ones. The virtual combinatorial library of previously unknown spiro-condensed derivatives of [1,2,4]triazino[2,3-c]quinazolines was formed and promising COX-2 inhibitors were identified by molecular docking method. Potential anti-inflammatory agents were synthesized by [5+1]-cyclocondensation of substituted 3-(2-aminophenyl)-6-R-1,2,4-triazin-5(2H)-ones with heterocyclic ketones. The structures of synthsized compounds were verified by complex of physicochemical methods and spectral characteristics features were discussed. Obtained compounds were studied for anti-inflammatory activity using formalin induced paw edema model and highly active compounds were identified. Conducted SAR-analysis showed that combination of triazino[2,3-c] quinazoline moiety with spiro-condensed fragments is a reasonable approach for creating novel anti-inflammatory agents.

Synthesis of 6-N-R-Tetrazolo[1,5-c]quinazolin-5(6H)-ones and Their Anticancer Activity

Chemical compounds with tetrazole ring are very interesting systems that can be valuable in pharmaceutical and clinical applications, especially as anticancer agents. In this work, novel 6-N-R-tetrazolo[1,5-c]quinazolin-5(6H)-ones were synthesized. A large set of IR, LC-, EI-MS, 1H, 13C NMR and elemental analysis data were collected and evaluated for their structures and purity. Details of synthesis, namely the N-alkylation, are discussed, including reactions with secondary and tertiary amides. Four new synthesized compounds (2.7, 3.2, 5.2, 5.3) were tested in vitro for anticancer activity at 10 μM against 60 cell lines of nine different cancer types: leukemia, melanoma, lung, colon, CNS, ovarian, renal, prostate, and breast cancers. Further synthesis of substances within the series of substituted tetrazolo[1,5-c]quinazoline systems will be attempted to develop improved compounds with better anticancer activity.

Adenocarcinoma of the lung with rare insertion mutation in EGFR exon 19 that had partial response to gefitinib: a case report

AIM

Classic activating mutations L858R and deletions in exon 19 (19del) in the gene for epidermal growth factor receptor (EGFR) are associated with sensitivity of the non-small cell lung cancer (NSCLC) to therapy with tyrosine kinase inhibitors (TKI). Insertions in EGFR exon 19 (19ins) are rare mutations in NSCLC; response of cases with 19ins to TKI is not well studied. Here we report a case of NSCLC with 19ins in a Russian patient who was treated with gefitinib. We also overview cases of 19ins reported in the literature.

CASE DESCRIPTION

A 48 years old female Russian patient was diagnosed with adenocarcinoma of the lung (T3N2M1, stage IV). Mutation 19ins was detected in the tumor biopsy by fragment analysis and genotyped by Sanger sequencing as p.I744_K745insKIPVAI. Treatment with gefitinib (250 mg/day) resulted in clinical and radiological improvements scored as partial response that lasted 12 months.

CONCLUSION

Treatment with gefitinib of lung adenocarcinoma that carries mutation EGFR 19ins can result in durable response.

2-alkyl(aryl)-quinazolin-4(3H)-thiones, 2-R-(quinazolin-4(3H)-ylthio)carboxylic acids and amides: synthesis, molecular docking, antimicrobial and anticancer properties

In this study, a series of novel 2-alkyl(aryl)-quinazolin-4(3H)-thiones, 2-R-(quinazolin-4(3H)-ylthio)carboxylic acids and amides were synthesized and evaluated for antimicrobial and anticancer activities. Their structure was confirmed by elemental analysis and spectral data (FT-IR, LC-MS, (1)H-NMR). Antimicrobial activity was tested in vitro against Staphylococcus aureus, Enterococcus faecalis, Enterobacter aerogenes, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, Candida albicans and NCI in vitro preliminary anticancer activity against nine different cancer types. The most active antibacterial and antifungal compounds were: 2.1, 2.2 and 2.4. The introduction of the carboxylic acid or amide residue into the fourth position of quinazolin-4(3H)-thione resulted in the absence of antimicrobial activity. Substance 3.8 inhibited renal cancer UO-31 line and 2.18 - leukemia CCRF-CEM. The results of in silico molecular docking for DHFR and CK2 kinase had no correlation with in vitro properties, proposing the presence of other biological activity pathways.

Neutrino propagation in nuclear medium and neutrinoless double-β decay

We discuss a novel effect in neutrinoless double-β (0νββ) decay related with the fact that its underlying mechanisms take place in the nuclear matter environment. We study the neutrino exchange mechanism and demonstrate the possible impact of nuclear medium via lepton-number-violating (LNV) four-fermion interactions of neutrinos with quarks from a decaying nucleus. The net effect of these interactions is the generation of an effective in-medium Majorana neutrino mass matrix. The enhanced rate of the 0νββ decay can lead to the apparent incompatibility of observations of the 0νββ decay with the value of the neutrino mass determined or restricted by the β-decay and cosmological data. The effective neutrino masses and mixing are calculated for the complete set of the relevant four-fermion neutrino-quark operators. Using experimental data on the 0νββ decay in combination with the β-decay and cosmological data, we evaluate the characteristic scales of these operators: ΛLNV≥2.4  TeV.

Incorporation of somatic BRAF mutation testing into an algorithm for the investigation of hereditary non-polyposis colorectal cancer

Patients suspected on clinical grounds to have hereditary non-polyposis colorectal cancer (HNPCC) may be offered laboratory testing in order to confirm the diagnosis and to facilitate screening of pre-symptomatic family members. Tumours from an affected family member are usually pre-screened for microsatellite instability (MSI) and/or loss of immunohistochemical expression of mismatch repair (MMR) genes prior to germline MMR gene mutation testing. The efficiency of this triage process is compromised by the more frequent occurrence of sporadic colorectal cancer (CRC) showing high levels of MSI (MSI-H) due to epigenetic loss of MLH1 expression. Somatic BRAF mutations, most frequently V600E, have been described in a significant proportion of sporadic MSI-H CRC but not in HNPCC-associated cancers. BRAF mutation testing has therefore been proposed as a means to more definitively identify and exclude sporadic MSI-H CRC cases from germline MMR gene testing. However, the clinical validity and utility of this approach have not been previously evaluated in a familial cancer clinic setting. Testing for the V600E mutation was performed on MSI-H CRC samples from 68 individuals referred for laboratory investigation of suspected HNPCC. The V600E mutation was identified in 17 of 40 (42%) tumours showing loss of MLH1 protein expression by immunohistochemistry but in none of the 28 tumours that exhibited loss of MSH2 expression (P < 0.001). The assay was negative in all patients with an identified germline MMR gene mutation. Although biased by the fact that germline testing was not pursued beyond direct sequencing in many cases lacking a high clinical index of suspicion of HNPCC, BRAF V600E detection was therefore considered to be 100% specific and 48% sensitive in detecting sporadic MSI-H CRC amongst those cases showing loss of MLH1 protein expression, in a population of patients with MSI-H CRC and clinical features suggestive of HNPCC. Accordingly, we recommend the incorporation of BRAF V600E mutation testing into the laboratory algorithm for pre-screening patients with suspected HNPCC, whose CRCs show loss of expression of MLH1. In such tumours, the presence of a BRAF V600E mutation indicates the tumour is not related to HNPCC and that germline testing of MLH1 in that individual is not warranted. We also recommend that in families where the clinical suspicion of HNPCC is high, germline testing should not be performed on an individual whose CRC harbours a somatic BRAF mutation, as this may compromise identification of the familial mutation.

KIT immunohistochemistry and mutation status in gastrointestinal stromal tumours (GISTs) evaluated for treatment with imatinib

AIMS

With the availability of effective but expensive treatment in the form of imatinib, accurate diagnosis of gastrointestinal stromal tumour (GIST) is extremely important. The aims of this study were: to describe the clinicopathological, immunohistochemical and molecular features of cases referred to a cancer centre with a possible diagnosis of GIST; to identify pitfalls in the performance and interpretation of KIT immunohistochemistry; to define the role of KIT mutation testing in making a diagnosis of GIST.

METHODS AND RESULTS

Morphological review, KIT immunohistochemistry and mutation testing were performed on all cases referred with a diagnosis of GIST or where the diagnosis was under serious consideration on the basis of KIT immunopositivity with a view to treating with imatinib. Thirty-seven cases met the inclusion criteria. Of these, 26 were classified as GIST and 11 as non-GIST. Most GISTs showed strong diffuse membranous, cytoplasmic or paranuclear KIT immunopositivity. Some non-GISTs demonstrated patchy cytoplasmic KIT immunopositivity related to the immunohistochemical protocol used in the external laboratory, which led to erroneous diagnoses of GIST in nine (24%) cases. KIT mutations involving exons 11 or 9 were identified in 22 (88%) GISTs tested and none of the non-GISTs.

CONCLUSIONS

An accurate diagnosis of GIST can be made on clinicopathological and immunohistochemical criteria without the need for mutational analysis in most cases, provided proper attention is paid to the immunohistochemical protocol used and, most importantly, control material. False-positive diagnoses of GIST potentially leading to inappropriate treatment with imatinib are more common than missed diagnoses.

Synthesis of substituted thienopyrimidine-4-ones

The parallel solution-phase synthesis of more than 3000 substituted thienopyrimidin-4-ones has been accomplished. Key reactions include assembly of the 2-thioxopyrimidin-4-one ring by condensation of isomeric aminothiophenecarboxylates or their appropriate reactive derivatives (isothiocyanates or dithiocarbamates) with the corresponding isothiocyanates or amines. The libraries from libraries were then obtained in good yields and purities using solution-phase alkylation and acylation methodologies. Simple manual techniques for parallel reactions using special CombiSyn synthesizers were coupled with easy purification procedures (crystallization from the reaction mixtures) to give high-purity final products. The scope and limitations of the developed approach are discussed.

Regio entorhinalis in schizophrenia: more evidence for migrational disturbances and suggestions for a new biological hypothesis

Recently we were able to replicate the original finding of migrational disturbances in the entorhinal cortex (ERC) of schizophrenic patients by measuring the distance of pre-alpha cell clusters to the pial surface. In order to replicate this finding, we performed a detailed analysis of the pre-alpha cell clusters in the ERC in post mortem brains of 22 schizophrenic patients and 15 control subjects. Cluster position relative to gray/white matter boundary were measured and normalized by the widths of the gray matter. In the ERC the pre-alpha cell clusters were situated significantly closer to the gray/white matter junction compared to normal controls (around 30 %, F = 9.52, p = 0.004). No specific effects of sex, age or region of investigation were found. In summary, this is another quantitative replication of pre-alpha cell cluster migrational disturbances in schizophrenia, which are possibly linked to neurobiological abnormalities, e.g. myeloarchitectonic changes. This supports the notion that developmental abnormalities are a core feature of schizophrenia and that the search for candidate genes has to include this aspect, too. However, it is very probable that vulnerability-associated changes - as outlined here - have to be distinguished from disease-related changes.

Examination of G72 and D-amino-acid oxidase as genetic risk factors for schizophrenia and bipolar affective disorder

A recent study has suggested that the brain-expressed genes for G72 and D-amino-acid oxidase (DAAO) exert an influence on susceptibility to schizophrenia. Our aim was to replicate this finding in German schizophrenic patients and to assess whether G72 and DAAO might also contribute to the development of bipolar affective disorder. We genotyped seven single-nucleotide polymorphisms (SNPs) in the G72 gene and three in the DAAO gene in 599 patients (299 schizophrenic, 300 bipolar) and 300 controls. At G72, individual SNPs and a four-marker haplotype were associated with schizophrenia. The most significant SNP as well as the haplotype were also associated with bipolar affective disorder (BPAD). DAAO was associated with schizophrenia, but not with BPAD. The association of variation at G72 with schizophrenia as well as BPAD provides molecular support for the hypothesis that these two major psychiatric disorders share some of their etiologic background.

The universality of bioenergetic disease. Age-associated cellular bioenergetic degradation and amelioration therapy

During the present century there has been a dramatic change in life expectancy in advanced societies, now exceeding 80 years. As distinct from life expectancy, life potential is said to be at least 120 years, so that the continuing increase in knowledge has the potential for further major changes in the survival of humans conceivably in the near future. This presentation will be concerned with one aspect of the development of biomedical advances related in part to a concept of an "age-related universality of bioenergetic disease," and its potential amelioration and proposed impact on age-related disease and lifestyle. Aging is a complex biological process associated with a progressive decline in the physiological and biochemical performance of individual tissues and organs, leading to age-associated disease and senescence. Consideration of the progressive accumulation of mitochondrial DNA mutation with age and the tissue/cellular bioenergy decline associated with the aging process has led us to the proposal of a "universality of bioenergetic disease" and the potential for a redox therapy for the condition. This concept envisages that a tissue-bioenergetic decline will be intrinsic to various diseases of the aged and thereby contribute to their pathology, in particular, heart failure, degenerative brain disease, muscle and vascular diseases, as well as other syndromes. The information and concepts embodied in this proposal will be reviewed under the following headings: (1) mitochondrial DNA deletion mutation in some tissue is very extensive and shows mosaicism; (2) age-associated tissue/cellular bioenergy mosaic closely corresponds to the mtDNA profile; (3) cellular bioenergy as a function of mitochondrial bioenergy, glycolysis, and plasma membrane oxidoreductase; (4) redox therapy for the reenergization of cells, tissues, and whole organs. A redox therapy based on coenzyme Q10 has demonstrated profound alteration in heart function of old rats; no significant effect was observed with young rats.

Rhizobium meliloti insertion element ISRm2 and its use for identification of the fixX gene

Two of the three plasmids of the wild-type Rhizobium meliloti 41 (pRme41a and pRme41c) carry a copy of ISRm2, a 2.7-kilobase-long transposable element. ISRm2 is terminated by 22-base-pair (bp) inverted repeat sequences, exhibiting some homology to the inverted repeats of elements generating 9-bp target sequence duplication. Transposition of ISRm2 results in a duplication of 8 bp in length, rather rare among transposable elements. DNA sequences homologous to an internal fragment of ISRm2 were found in several Rhizobium species. Transposition of ISRm2 into fixation and nodulation genes located on the symbiotic plasmid pRme41b was detected at a high frequency. Exact locations of two copies of ISRm2 which transposed into the nod-nif region on the megaplasmid were determined. In one case, integration into the protein-coding region of the hsnD gene that determines a host specificity function of nodulation occurred. In the other mutant, ISRm2 was localized upstream of nifA, where a short open reading frame coding for a new fix gene (fixX) was identified. The product of fixX is a ferredoxin carrying a characteristic cluster of cysteine residues. On the basis of the observation that the arrangement of the ISRm2 copies is identical in the free-living wild-type cells and in nitrogen-fixing nodules, we concluded that the involvement of ISRm2 transposition in the development of nitrogen-fixing symbiosis is unlikely.