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The prepared oxazolopyrimidine derivatives exhibited high anti-breast-cancer activity and ADK suppression, indicating their potential as candidates in the targeted search for new, highly effective antitumor drugs.

The design and development of new phosphorus-containing amino acids and peptidomimetics have been attracting considerable attention due to their value as intermediates in the synthesis of biologically active compounds and the prospects for further pharmacological applications. 1,3-Oxazole derivatives, as masked peptides, constitute an important group of amino acid precursors that are widely used in contemporary organic synthesis. This review presents the 1,3-oxazole-based synthetic strategies of phosphorylated amino acids and peptides that have been published in both journal and patent literature. We have focused specifically on the synthesis of 4-phosphorylated 1,3-oxazoles as precursors of phosphopeptide mimetics containing the peptide chain with a non-terminal phosphono group due to the growing interest in finding efficient methods for the synthesis of this little-studied class of compounds

The effective and simple synthetic preparative procedure for obtaining of various derivatives of 2-aryl-5,6-dihydropyrano[2,3-c]pyrrole-4,7-diones applying the I2/DMSO oxidation of 3-hydroxy-4-[(2E)-3-arylprop-2-enoyl]-1,5-dihydro-2H-pyrrol-2-ones was developed. This protocol was found to be compatible with a wide range of substituents and gave the reliable synthetic pathway for the obtaining of target compounds with a wide range of substituents under mild conditions. All obtained substances can be easily isolated and purified by crystallization without application of more complex and labour intensive purification methods

The problem of designing new antiviral drugs against Human Cytomegalovirus (HCMV) was addressed using the Online Chemical Modeling Environment (OCHEM). Data on compound antiviral activity to human organisms were collected from the literature and uploaded in the OCHEM database. The predictive ability of the regression models was tested through cross-validation, giving coefficient of determination q2 = 0.71–0.76. The validation of the models using an external test set proved that the models can be used to predict the activity of newly designed compounds with reasonable accuracy within the applicability domain (q2 = 0.70–0.74). The models were applied to screen a virtual chemical library of imidazole derivatives, which was designed to have antiviral activity. The six most promising compounds were identified, synthesized and their antiviral activities against HCMV were evaluated in vitro. However, only two of them showed some activity against the HCMV AD169 strain.

Abstract The reaction of the newly synthesized N-(2,2-dichloro-1-cyanoethenyl)prop-2-enamide and 4-chloro-N-(2,2-dichloro-1-cyanoethenyl)butanamide with methylamine or dimethylamine gave rise to previously unknown 5-amino-1,3-oxazole-4-carbonitriles. In the case of the reaction of N-(2,2-dichloro-1-cyanoethenyl)amides with ethylenediamine diacetate, new (Z)-2,3,5,6,7,8-hexahydro-7-oxo-1H-imidazo[1,2-a][1,4]diazepine-9-carbonitrile and 4-chloro-N-(cyano(imidazolidin-2-ylidene)methyl)butanamide were obtained.

A novel series of 1,3-oxazol-4-yltriphenylphosphonium salts has been synthesized and functionalized. Oxazole derivatives were subjected to NCI in vitro assessment. Seven most active derivatives have been selected for five-dose assay. Among them, compounds 9 ([2-(4-methylphenyl)-5-[(4-methylphenyl)sulfanyl]-1,3-oxazol-4-yl]triphenylphosphonium perchlorate), 1 ([5-(4-methylphenyl)amino]-2-phenyl-1,3-oxazol-4-yl]triphenylphosphonium perchlorate) and 4 ([5-phenyl-2-[(4-methylphenyl)amino]-1,3-oxazol-4-yl]triphenylphosphonium perchlorate) were the most active against all tested cancer subpanels. Statistical analysis of the total panel data showed average values of parameters of anticancer activity in the range of 0.3-1.1 μM (GIsub50/sub), 1.2-2.5 μM (TGI) and 5-6 μM (LCsub50/sub). It was found that the presence of phenyl or 4-methylphenyl groups at C(2) and C(5) in the oxazole ring is of critical importance for the manifestation of the anticancer activity. Matrix COMPARE analysis using LCsub50/subvector showed a high positive correlation of compound 9 with standard anticancer agents that can directly disrupt mitochondrial function, causing programmed death of cancer cells. The obtained results indicate the anticancer activity of 1,3-oxazol-4-ylphosphonium salts, which could be useful for developing new anticancer drugs. The most active of them can be recommended for further in-depth studies and synthesis of new derivatives with antitumor activity on their basis.

The oxazole and pyrimidine rings are widely displayed in natural products and synthetic molecules. They are known as the prime skeletons for drug discovery. On the account of structural and chemical diversity, oxazole and pyrimidine-based molecules, as central scaffolds, not only provide different types of interactions with various receptors and enzymes, showing broad biological activities, but also occupy a core position in medicinal chemistry, showing their importance for development and discovery of newer potential therapeutic agents (Curr Top Med Chem, 16, 2016, 3133; Int J Pharm Pharm Sci, 8, 2016, 8; BMC Chem, 13, 2019, 44). For a long time, relatively little attention has been paid to their fused rings that are oxazolopyrimidines, whose chemical structure is similar to that of natural purines because probably none of these compounds were found in natural products or their biological activities turned out to be unexpressed (Bull Chem Soc Jpn, 43, 1970, 187). Recently, however, a significant number of studies have been published on the biological properties of oxazolo[5,4-d]pyrimidines, showing their significant activity as agonists and antagonists of signaling pathways involved in the regulation of the cell life cycle, whereas oxazolo[4,5-d]pyrimidines, on the contrary, represent a poorly studied class of compounds. Limited access to this scaffold has resulted in a corresponding lack of biological research (Eur J Organ Chem, 18, 2018, 2148). Actually, oxazolo[5,4-d]pyrimidine is a versatile scaffold used for the design of bioactive ligands against enzymes and receptors. This review focuses on biological targets and associated pathogenetic mechanisms, as well as pathological disorders that can be modified by well-known oxazolopyrimidines that have been proven to date. Many molecular details of these processes are omitted here, which the interested reader will find in the cited literature. This work also does not cover the methods for the synthesis of the oxazolopyrimidines, which are exhaustively described by De Coen et al. (Eur J Organ Chem, 18, 2018, 2148). The review as well does not discuss the structure-activity relationship, which is described in detail in the original works and deliberately, whenever possible, cites not primary sources, but mostly relevant review articles, so that the reader who wants to delve into a particular problem will immediately receive more complete information. It is expected that the information presented in this review will help readers better understand the purpose of the development of oxazolopyrimidines and the possibility of their development as drugs for the treatment of a wide range of diseases.

A number of sulfamides were obtained by reaction of (5-(dichloromethylene)-2-oxoimidazolidin-4-ylidene)sulfamoyl chloride with anilines, benzylamines, Boc-protected piperazine, methylalylamine, and amino acids methyl esters with primary and secondary amino group. The antiviral and anticancer activity of new derivatives was evaluated. The most effective compounds against Human cytomegalovirus were sulfamides based on anisidine (1b), N-Boc-piperazine (1h), and the derivatives 1n,o with fragments of nipecotic and azetidine-3-carboxylic acids, respectively. Anticancer activity was most significant for sulfamides based on p-methoxybenzylamine (compound 1d), benzylmethylamine (compound 1f), and allylmethylamine (compound 1g).

The previously established in vitro high antimicrobial potential of triphenylphosphonium salts (TPPs) against bacterial (Staphylococcus aureus ATCC 25923 and multi-drug resistant (MDR)) and fungal (Candida albicans ATCC 10231 and MDR) strains made it possible to propose a molecular mechanism of action of these compounds associated with transglycosylase (TG) activity. The hypothesis was based on the well-known literature data on TPPs as inhibitors of S. aureus TG. The created homology model of TG C. albicans is optimal in terms of such quality indicators as GMQE (0.61), ERRAT (overall quality factor 95.904) and Ramachandran plot analysis (90% amino acid residues in the favored regions). Molecular docking of the most active ligands 1a-d, 3c into the active center of the created homology C. albicans TG model demonstrated the formation of stable ligand-protein complexes with binding energies in the range from -8.9 to -9.7 kcal/mol due to the various types of interactions. An important role in complex formation belongs to amino acid residues TYR307, TYR107, GLU275, ALA108 and PRO136. The presented qualitative homologous model of C. albicans TG can be used to search and create new agents with a dual mechanism of antimicrobial action. 1,3-oxazol-4-yltriphenylphosphonium salts 1a-d, 3c perform the perspective objects for further study as antimicrobials against infectious MDR pathogens.

The reaction of substituted 3,3-dichloroprop-2-enenitriles containing an N-methylurea or N,N-dimethylurea residue in the second position with secondary aliphatic amines gives rise to previously unknown 2,5-bis(alkylamino)-1,3-oxazole-4-carbonitriles. In the case of the reaction of N-(2,2-dichloro-1-cyanoethenyl)-N′-methylureas with benzylamines, 4,5-bis(alkylamino)-1-methyl-1H-imidazol-2(5H)-ones were obtained.

The simultaneous quantum-chemical and spectral investigations of the possible relaxation pathways in the excited state for the two α,ω-di-substituted polyenes were performed. Lengthening of the polymethine chain is accompanied by the considerable decreasing of the first electron transition and hence is manifested as the bathochromic shift of both absorption and fluorescence spectra; however, the nature of transition does not change. It is established that the considerable changes of the bond lengths in polymethine chain for both vinylogs in the excited state cause firstly the appearance of the fast component in short wavelengths spectral region; after relaxation, the intensity of the fast component decreases, and it disappears, but then the spectral band, shifted bathochromically, appears, so that its maximum coincide with the band maximum in the steady-state fluorescence maximum, what corresponds to the final symmetrical relaxation of bond lengths. The parallel quantum-chemical calculation shows that two highest levels are mainly formed by the donor levels of both terminal groups and hence twice occupied splitting levels. Upon excitation, one of the splitting MO (HOMO) becomes single occupied; this causes the molecule in the excited state to be unstable and could transform it to the unsymmetrical form. Such relaxation path is confirmed by the time-resolved spectra: the spectral band in both molecules, with the different polymethine chains, undergoes the subsequent bathochromical shifting.

A method for the synthesis of a series of new substituted 1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones was proposed based on the Diels–Alder type reaction of 4-methoxy-1,3-oxazoles with maleimide derivatives.

Thiazole-containing derivatives of rhodanine-3-alkanoic acids with propanoic or undecanoic acid groups were synthesized and evaluated as inhibitors of some protein tyrosine phosphatases and glutathione S-transferases. The rhodanines bearing longer carboxylated N-alkyl chain were found to inhibit PTP1B, MEG1, MEG2, and VE-PTP as well as GST from equine liver and GSTA1-1 with IC50 values in the low micromolar range. The inhibitory effect on protein tyrosine phosphatase activity depends on substituent at position 2 of the thiazole ring. The best compound showed a competitive type of VE-PTP inhibition. In case of GST from equine liver, the inhibition was of mixed or non-competitive type with respect to glutathione or CDNB substrate, respectively. Possible binding modes of the inhibitors were discussed based on molecular docking calculations.

The binding affinity of model aromatic amino acids and heterocycles and their derivatives condensed with pyridine were investigated in silico and are presented in the framework of fragment-to-fragment approach. The presented model describes interaction between pharmacophores and biomolecules. Scrupulous data analysis shows that expansion of the π-electron system by heterocycles annelation causes the shifting up of high energy levels, while the appearance of new the dicoordinated nitrogen atom is accompanied by decreasing of the donor-acceptor properties. Density Functional Theory (DFT) wB97XD/6-31(d,p)/calculations of π-complexes of the heterocycles 1-3 with model fragments of aromatic amino acids, which were formed by π-stack interaction, show an increase in the stabilization energy of π-complexes during the moving from phenylalanine to tryptophan. DFT calculation of pharmacophore complexes with model proton-donor amino acid by the hydrogen bonding mechanism (H-B complex) shows that stabilization energy (DE) increases from monoheterocycles to their condensed derivatives. The expansion of the π-electron system by introducing phenyl radicals to the oxazole cycle as reported earlier [18] leads to a decrease in the stabilization energy of the [Pharm-BioM] complexes in comparison with the annelated oxazole by the pyridine cycle.

2-Aryl-2-(2-aryl-2-oxoethyl)-1H,2H,3H-imidazo[1,2-a]pyridin-4-ium bromides were obtained in the reaction of (2Z)-4-bromo-1,3-diphenylbut-2-en-1-one derivatives with 2-aminopyridines in benzene. The effect of the structure of the starting reagents on the results of the reactions was studied. Antitumor activity of 2-(4-chlorophenyl)-2-[2-(4-chlorophenyl)-2-oxoethyl]-1H,2H,3H-imidazo[1,2-a]pyridin-4-ium bromide was determined, which showed high antitumor potential of the test compound on 60 human cancer cell lines.

New synthetic compounds — pyrimidine derivatives — were screened to select the most effective of them, which show a growth-regulating activity in plants. Their action was compared with phytohormones of the auxin class. In particular, the effect of synthetic compounds on the seed germination, growth, and development of tomato (Solanum lycopersicum L.) plants of Lagidny variety in vivo and in vitro was studied. It was found that some of the studied compounds have a positive effect on the morphometric and biochemical parameters of 30-day-old plants: compounds D1-D5 increased seed germination up to 9-27 %, the most effective among them was compound D1. Compounds D1 and D2 increased the height of the shoots up to 29 %. All the studied compounds effectively influenced the rooting of plants, increasing either the length of the roots (up to 8 %) or their number (up to 25 %), the most effective among them was the compound D2. The effect of these compounds on the morphogenetic potential of tomato explants was studied in vitro for the first time. It was found that compounds D1 and D2 were the most effective for the direct plant regeneration. Screened compounds can be further recommended for the use in various biotechnological programs for genetic improvement of tomatoes.

Functionalization of heterocyclic systems with sulfur- and phosphorus-containing pharmacophores has long shown itself as an effective method for construction of new bioactive substances. At the same time, some types of the compounds are represented by only a few examples, and it prevents further evaluation of the contribution of certain structural elements to biological effects of the sulfonyl- and phosphoryl-substituted heterocyclic derivatives studied. Therefore, a relevant task for organic and medicinal chemistry still remains development of new methods for the synthesis of heterocyclic compounds with sulfonyl and phosphoryl groups, as well as determination of the biological activity of these substances. A structural variety of sulfonyl- and phosphoryl-substituted heterocycles can be achieved by using heterofunctional low-molecular compounds with sulfonyl and phosphoryl groups. This review highlights the information on biologically active heterocyclic compounds synthesized from acrylonitriles and enamines of sulfones, phosphine oxides, and phosphonates series.Received: 05.02.2020Revised: 25.05.2020Accepted: 27.08.2020

A potential of using nickel complexes with 1,3-dicarbonyl compounds for the transformation of heterocyclic aminonitriles into fused systems with a 4-aminopyridine core was evaluated. A possibility of introducing acidophobic groups into the molecules of fused compounds was shown.

We propose a new method for assembling the imidazo[2,1-b][1,3]thiazole system, based on the reaction of (2Z)-1,3-diaryl-4-bromobut-2-en-1-one derivatives with 2-aminothiazoles. The outcome of this reaction depends on the structure of the starting bromo ketone: when electron-withdrawing substituents are present in the structure of the ketone, a competing reaction occurs, which leads to the formation of 2,5-diarylfurans. Screening for antitumor activity has been performed in the case of 1-phenyl-2-(6-phenyl-5,6-dihydroimidazo[2,1-b]- thiazol-6-yl)ethanone and this compound has shown moderate ability to suppress the growth of kidney cancer cells, with a weaker effect on the cell lines of prostate cancer, colon cancer, and leukemia.

A convenient method was developed for the synthesis of novel isoquinolin-1(2H)-ones, 1-chloroisoquinolines, and 1-aminoisoquinolines with a heterocyclic substituent in position 3 via a recyclization of 3-hetarylisocoumarins with (NH4)2CO3. 1-Aminoisoquinolines were efficiently obtained from corresponding 1-chloro-3-hetarylisoquinolines (obtained by interaction of isoquinolin-1(2H)-ones with POCl3) and cyclic secondary amines (morpholine or 1-methylpiperazine). Literature data and preliminary results of biological assays allow to consider 1-amino-3-hetarylisoquinolines a promising family of anticancer compounds.

New pyrazolo[1,5-a][1,3,5]triazines with a heteroaromatic substituent in position 4 and dichloromethyl moiety in position 2 were obtained via a heterocyclization reaction of readily available reagents - N-(2,2-dichloro-1-cyanoethenyl)carboxamides and 3(5)-aminopyrazoles. The high efficiency of the proposed method for the synthesis of 2-(dichloromethyl)-pyrazolo[1,5-a][1,3,5]triazines with furan-2-yl, thien-2-yl, and pyridine-3-yl substituents was demonstrated.

Background: Tuberculosis (TB) is an infection disease caused by Mycobacterium tuberculosis (Mtb) bacteria. One of the main causes of mortality from TB is the problem of Mtb resistance to known drugs. Objective: The goal of this work is to identify potent small molecule anti-TB agents by machine learning, synthesis and biological evaluation. Methods: The On-line Chemical Database and Modeling Environment (OCHEM) was used to build predictive machine learning models. Seven compounds were synthesized and tested in vitro for their antitubercular activity against H37Rv and resistant Mtb strains. Results: A set of predictive models was built with OCHEM based on a set of previously synthesized isoniazid (INH) derivatives containing a thiazole core and tested against Mtb. The predictive ability of the models was tested by a 5-fold cross-validation, and resulted in balanced accuracies (BA) of 61–78% for the binary classifiers. Test set validation showed that the models could be instrumental in predicting anti- TB activity with a reasonable accuracy (with BA = 67–79 %) within the applicability domain. Seven designed compounds were synthesized and demonstrated activity against both the H37Rv and multidrugresistant (MDR) Mtb strains resistant to rifampicin and isoniazid. According to the acute toxicity evaluation in Daphnia magna neonates, six compounds were classified as moderately toxic (LD50 in the range of 10−100 mg/L) and one as practically harmless (LD50 in the range of 100−1000 mg/L). Conclusion: The newly identified compounds may represent a starting point for further development of therapies against Mtb. The developed models are available online at OCHEM http://ochem.eu/article/11 1066 and can be used to virtually screen for potential compounds with anti-TB activity.

Anticancer activity of a series of polyfunctional substituted 1,3-thiazoles has been studied within the international scientific program “NCI-60 Human Tumor Cell Lines Screen”. Screening was performed in vitro on 60 cell lines of lungs, kidneys, CNS, ovaries, prostate, and breast cancer, epithelial cancer, leukemia, and melanoma. The most effective compounds were those with a piperazine substituent at C2 of the 1,3-thiazole cycle: 1-(4-((4-methylphenyl)-sulfonyl)-2-phenyl-1,3-thiazol-5-yl)piperazine (average lg GI50 = -5.87, lg TGI = -5.54, lg LC50 = -5.21), 1-(2-(3,5-dimethyl-1H-pyrazol-1-yl)-4-((4-methylpheyl)sulfonyl)-1,3-thiazol-5-yl)piperazine (average lg GI50 = -5.66, lg TGI = -5.26, lg LC50 = -4.83), and 1-(2,4-bis((4-methylphenyl)sulfonyl)-1,3-thiazol-5-yl)piperazine (average lg GI50 = -5.67, lg TGI = -5.21, lg LC5050 = -4.67).

Synthetic 6-substituted purine derivatives are known to exhibit diverse bioactivity. In this paper, a series of N-(9H-purin-6-yl)-1,2-oxazole-3-carboxamide derivatives were synthesized and evaluated in vitro against xanthine oxidase, an enzyme of purine catabolism. The introduction of aryl substituent at position 5 of the oxazole ring was found to increase the inhibition efficiency. Some of the inhibitors containing 5-substituted isoxazole and purine moieties were characterized by IC50 values in the nanomolar range. According to the kinetic data, the most active N-(9H-purin-6-yl)-5-(5,6,7,8-tetrahydronaphthalen-2-yl)-1,2-oxazole-3-carboxamide demonstrated a competitive type of inhibition with respect to the enzyme-substrate. Molecular docking was carried out to elucidate the mechanism of enzyme-inhibitor complex formation. The data obtained indicate that xanthine oxidase may be one of the possible targets for the bioactive purine carboxamides.

A versatile and efficient three-component cyclization of methyl 4-(o-hydroxyphenyl)-2,4-dioxobutanoates 1, N-substituted isatins 2, and primary amines 3 was explored to synthesize of 2H-spiro[chromeno[2,3-c]pyrrole-1,3'-indoline]-2',3,9-triones. We obtained a library of 122 derivatives with an indolin-2-one motif as an important structural fragment in natural alkaloids. This method is practical and useful strategy for constructing dihydrochromeno[2,3-c]pyrrole-3,9-diones. Most of the obtained products also have functional groups for easy and further diversification by classical reactions.

A series of 2,2-disubstituted 8-azachromanones, including spirocyclic compounds, have been synthesized via Horner–Wadsworth– Emmons reaction. Dimethyl methylphosphonate was acylated with methyl 2-methoxypyridine-3-carboxylate to afford the key intermediate – dimethyl [2-(2-methoxypyridin-3-yl)-2-oxoethyl]phosphonate. Further reaction of this phosphonate and ketones followed by treatment with TMSCl–NaI provided the target 8-azachromanones. Scope and limitations of the developed synthetic method have been investigated.

Method of quantitative estimation of the π-electron affinity for conjugated molecules, which is directly related to donor/acceptor properties is presented. The index φ0 is proposed, it is determine...

Five imidazo[1,2-c]pyrimidine and pyrimido[1,6-a]pyrimidine derivatives were designed, synthesized and evaluated for their antiproliferative activity and cytotoxicity. Primary bioassays in vitro showed that two of five synthesized compounds, 6-benzyl-8-(methylsulfonyl)-2,6-dihydroimidazo[1,2-c]pyrimidin-5(3H)-one, and 9-(methylsulfonyl)-7-propyl-2,3,4,7-tetrahydro-6H-pyrimido[1,6-a]pyrimidin-6-one possessed potent antiviral activity against BKV (EC50: 0.66 μM and 0.96, respectively). The selectivity index of these compounds is similar to that of cidofovir. Although antiviral activity was evident in secondary assays, significant virus inhibition occurred at or near the cytotoxic concentration (SI90=1). Here we show that substituted pyrimidine derivatives are a promising structure class of chemical compounds for the development of antiviral drugs against BKV infections. Hence these compounds may be taken as lead compounds for further development of novel antimicrobial and anticancer agents.

The possibilities of 2-amino-3,3-dichloroacrylonitrile (ADAN) used for the construction of macrocyclic structures such as cyclophanes with two oxazole fragments are investigated. For this purpose, bifunctional reagents were used in the classic ADAN transformation into 5-amino-4-cyanooxazoles (sequential treatment of ADAN with acyl chloride and a primary or secondary amine). As a result of the reaction of 2,2'‎-(1,2-phenylene)-diacetyl chloride with 2 eq of ADAN, a compound with two acrylonitrile fragments, 2,2' ‎- (1,2-phenylene)bis(N- (2,2-dichloro-1-cyanovinyl)acetamide), was obtained. In this substance, both ADAN residues can interact with amines and form oxazole cycles: for example, the treatment with an excess of dimethylamine produces 2,2'‎ - (1,2-phenylenebis(methylene))bis(5-(dimethylamino)oxazole-4-carbonitrile). The target macrocyclic structure was obtained by the interaction of 2,2'‎ - (1,2-phenylene)bis(N-(2,2-dichloro-1-cyanovinyl)acetamide) with butane-1,4-diamine, as a result the simultaneous forming of both oxazole rings and an aliphatic bridge connected with them was happened. At this stage, it was used a procedure, that is typical of the creation of macrocyclic structures based on polyfunctional reagents, — strong dilution (about 0.04 M). The molecule of the synthesized 6,11-diaza-1,5(2,5)-dioxazole-3(1,2)-benzenecycloundecaphan-14,54-dicarbonitrile has high spatial symmetry, which is confirmed by the presence of only one series of peaks in the 1H and 13C NMR spectra (for example, the butane-1,4-diamine fragment in the aliphatic part of the spectrum looks likes two triplets). The formation of a macrocyclic structure is evidenced by HPLC-MS data, as well as homo- and heteronuclear correlations in the NMR spectra. The proposed procedure for the synthesis of 6,11-diaza-1,5(2,5)-dioxazole-3(1,2)-benzenecycloundecaphan- 14,54-dicarbonitrile is based on the use of simple and inexpensive reagents, and the total yield of the target substance in two stages starting with the 2,2'‎ - (1,2-phenylene)diacetyl chloride, is 51 %.

A series of benzenesulfonamides incorporating pyrazole- and pyridazinecarboxamides decorated with several bulky moieties has been obtained by original procedures. The new derivatives were investigated for the inhibition of four physiologically crucial human carbonic anhydrase (hCA, EC 4.2.2.1.1) isoforms, hCA I and II (cytosolic enzymes) as well as hCA IX and XII (transmembrane, tumor-associated isoforms). Examples of isoform-selective inhibitors were obtained for all four enzymes investigated here, and a computational approach was employed for explaining the observed selectivity, which may be useful in drug design approaches for obtaining inhibitors with pharmacological applications useful as antiglaucoma, diuretic, antitumor or anti-cerebral ischemia drugs.

Carbonic Anhydrases (CAs) are ubiquitous metalloenzymes involved in several disease conditions. There are 15 human CA (hCA) isoforms and their high homology represents a challenge for the discovery of potential drugs devoid of off-target side effects. For this reason, many synthetic and pharmacologic research efforts are underway to achieve the full pharmacological potential of CA modulators of activity. We report here a novel series of sulfanilamide derivatives containing heterocyclic carboxamide moieties which were evaluated as CA inhibitors against the physiological relevant isoforms hCA I, II, IX, and XII. Some of them showed selectivity toward isoform hCA II and hCA XII. Molecular docking was performed for some of these compounds on isoforms hCA II and XII to understand the possible interaction with the active site amino acid residues, which rationalized the reported inhibitory activity.

The ability of fullerene to form stable π → π-complexes was studied by quantum-chemical methods and the fluorescence quenching of reference dye (thiochrome). The correlation between the theoretically calculated and experimentally obtained energy of the π → π-complexes was determined. The energy of the stack interaction between fullerene and some biological active compounds, derivatives of 1,3-oxazoles, containing donor/acceptor substituents was estimated.

This minireview highlights known methods for the synthesis of azachromones and azachromanones, including the earliest and the latest examples of their synthesis. Methods considered for constructing azachromone or azachromanone system include intramolecular heterocyclization, deprotection–cyclization, spirocyclization, cyclization–aromatization, Ullman-type O-arylation, and C–H activation of pyridine N-oxides.

Two protocols for the combinatorial synthesis of 5-(dialkylamino)tetrazoles were developed. The best success rate (67%) was shown by the method which used primary and secondary amines, 2,2,2-trifluoroethylthiocarbamate and sodium azide as the starting reagents. The key steps included the formation of unsymmetrical thiourea, subsequent alkylation with 1,3-propane sultone and cyclization with azide anion. A 559-member aminotetrazole library was synthesized by this approach; the overall readily accessible (REAL) chemical space covered by the method exceeded 7 million feasible compounds.