Thiouracil and triazole conjugate induces autophagy through the downregulation of Wnt/ß-catenin signaling pathway in human breast cancer cells.

Autophagy is vital for maintaining cellular homeostasis by breaking down unnecessary organelles and proteins within cells. Its activity varies abnormally in several diseases, including cancer, making it a potential target for therapeutic strategies. The Wnt/ß-catenin signaling pathway significantly impacts cancer by stabilizing ß-catenin protein and promoting the transcription of its target genes. Therefore, we aimed to identify candidate substances targeting this signaling pathway. We designed and tested a thiouracil conjugate, discovering that TTP-8 had anti-tumor effects on human breast cancer cell lines MCF-7 and MDA-MB231. Our findings showed that TTP-8 upregulated the expression of LC3 protein, a marker of autophagy in breast cancer cells, suggesting that TTP-8 might induce autophagy. Further analysis confirmed an increase in autophagy-related proteins, with consistent results obtained from flow cytometry and confocal microscopy. Interestingly, the induction of LC3 expression by TTP-8 was even more pronounced in MCF-7 and MDA-MB231 cells transfected with ß-catenin siRNA. Thus, our research supports the idea that the Wnt/ß-catenin signaling pathway influences the regulation of autophagy-related proteins, thereby inducing autophagy. This suggests that TTP-8 could serve as a novel agent for treating breast cancer.

Structure-property relationship in thioxotriaza-spiro derivative: Crystal structure and molecular docking analysis against SARS-CoV-2 main protease.

Detailed structural and non-covalent interactions in thioxotriaza-spiroderivative (DZ2) are investigated by single crystal structure anslysis and computational approaches. Its results were compared with the previously reported spiroderivative (DZ1). The crystal structure analysis revealed various C-H…O, N-H…O, C-H…N and N-H…S hydrogen bonds involved in constructing several dimeric motifs to stabilize the crystal packing. The differences and similarities in the relative contribution of non-covalent interactions in DZ1 and DZ2 compounds are compared using the Hirshfeld surface analysis and 2D fingerprint plots. The binding energies of specific molecular pairs and homodimers have been obtained using molecule-molecule interaction energy calculation. The hierarchy and topology of pair-wise intermolecular interactions are visualized through energy frameworks. The nature and strength of intra and intermolecular interactions were characterized using non-covalent interaction index analysis and the quantum theory of atoms in molecule approach. Further, molecular docking of compounds (DZ1 and DZ2) with SARS-CoV-2 main protease for COVID-19 is performed. And the superposition of these ligands and inhibitor N3, which is docked into the binding pocket of 7BQY, is presented. The binding affinity of -6.7 kcal/mol is observed, attributed to hydrogen bonding and hydrophobic interactions between the ligand and the amino acid residues of the receptor.

Furan-2-carboxamide derivative, a novel microtubule stabilizing agent induces mitotic arrest and potentiates apoptosis in cancer cells.

The vital role played by microtubules in the cell division process, marks them as a potential druggable target to decimate cancer. A novel furan-2-carboxamide based small molecule, is a selective microtubule stabilizing agent (MSA) with IC50 ranging from 4 µM to 8 µM in different cancer cell lines. Inhibition of tubulin polymerization or stabilization of tubulin polymers abrogates chromosomal segregation during cell division, results in cell cycle arrest and leads to cell death due to the delayed repair mechanism. A novel furan-2-carboxamide based small molecule exhibited potent anti-proliferative and anti-metastatic property In-Vitro against the panel of cancer cells. Annexin V-FITC/PI, double staining reveals potent cytotoxic effect of SH09 against HeLa cells. FACS analysis displays induction of G2/M arrest and accumulation of subG1 population of cells upon treatment with SH09. Molecular docking study unveils SH09 binding affinity to the Taxol binding pocket of tubulin proteins and MM-GBSA also confirms strong binding energies of SH09 with tubulin proteins.

Virtual analysis of structurally diverse synthetic analogs as inhibitors of snake venom secretory phospholipase A2.

Due to the toxic pathophysiological role of snake venom phospholipase A2 (PLA2 ), its compelling limitations to anti-venom therapy in humans and the need for alternative therapy foster considerable pharmacological interest towards search of PLA2 specific inhibitors. In this study, an integrated approach involving homology modeling, molecular dynamics and molecular docking studies on VRV-PL-V (Vipera russellii venom phospholipase A2 fraction-V) belonging to Group II-B secretory PLA2 from Daboia russelli pulchella is carried out in order to study the structure-based inhibitor design. The accuracy of the model was validated using multiple computational approaches. The molecular docking study of this protein was undertaken using different classes of experimentally proven, structurally diverse synthetic inhibitors of secretory PLA2 whose selection is based on IC50 value that ranges from 25 µM to 100 µM. Estimation of protein-ligand contacts by docking analysis sheds light on the importance of His 47 and Asp 48 within the VRV-PL-V binding pocket as key residue for hydrogen bond interaction with ligands. Our virtual analysis revealed that compounds with different scaffold binds to the same active site region. ADME analysis was also further performed to filter and identify the best potential specific inhibitor against VRV-PL-V. Additionally, the e-pharmacophore was generated for the best potential specific inhibitor against VRV-PL-V and reported here. The present study should therefore play a guiding role in the experimental design of VRV-PL-V inhibitors that may provide better therapeutic molecular models for PLA2 recognition and anti-ophidian activity.

Crystal structure of ATP-binding subunit of an ABC transporter from Geobacillus kaustophilus.

The ATP binding cassette (ABC) transporters, represent one of the largest superfamilies of primary transporters, which are very essential for various biological functions. The crystal structure of ATP-binding subunit of an ABC transporter from Geobacillus kaustophilus has been determined at 1.77 Å resolution. The crystal structure revealed that the protomer has two thick arms, (arm I and II), which resemble 'L' shape. The ATP-binding pocket is located close to the end of arm I. ATP molecule is docked into the active site of the protein. The dimeric crystal structure of ATP-binding subunit of ABC transporter from G. kaustophilus has been compared with the previously reported crystal structure of ATP-binding subunit of ABC transporter from Salmonella typhimurium.

Melatonin alleviates Echis carinatus venom-induced toxicities by modulating inflammatory mediators and oxidative stress.

Viper bites cause high morbidity and mortality worldwide and regarded as a neglected tropical disease affecting a large healthy population. Classical antivenom therapy has appreciably reduced the snakebite mortality rate; it apparently fails to tackle viper venom-induced local manifestations that persist even after the administration of antivenom. Recently, viper venom-induced oxidative stress and vital organ damage is deemed as yet another reason for concern; these are considered as postmedicated complications of viper bite. Thus, treating viper bite has become a challenge demanding new treatment strategies, auxiliary to antivenin therapy. In the last decade, several studies have reported the use of plant products and clinically approved drugs to neutralize venom-induced pharmacology. However, very few attempts were undertaken to study oxidative stress and vital organ damage. Based on this background, the present study evaluated the protective efficacy of melatonin in Echis carinatus (EC) venom-induced tissue necrosis, oxidative stress, and organ toxicity. The results demonstrated that melatonin efficiently alleviated EC venom-induced hemorrhage and myonecrosis. It also mitigated the altered levels of inflammatory mediators and oxidative stress markers of blood components in liver and kidney homogenates, and documented renal and hepatoprotective action of melatonin. The histopathology of skin, muscle, liver, and kidney tissues further substantiated the overall protection offered by melatonin against viper bite toxicities. Besides the inability of antivenoms to block local effects and the fact that melatonin is already a widely used drug promulgating a multitude of therapeutic functionalities, its use in viper bite management is of high interest and should be seriously considered.

Therapeutic drug-induced platelet apoptosis: an overlooked issue in pharmacotoxicology.

The surfacing of the applied fields of biology such as, biotechnology, pharmacology and drug discovery was a boon to the modern man. However, it had its share of disadvantages too. The indiscriminate use of antibiotics and other biological drugs resulted in numerous adverse reactions including thrombocytopenia. One of the reasons for drug-induced thrombocytopenia could be attributed to an enhanced rate of platelet apoptosis, which is a less investigated aspect. The present essay sheds light on the adverse (pro-apoptotic) effects of some of the commonly used drugs and antibiotics on platelets viz. cisplatin, aspirin, vancomycin and balhimycin. Furthermore, the undesirable reactions resulting from chemotherapy could be attributed at least to some extent to the systemic stress induced by microparticles, which in turn are the byproducts of platelet apoptosis. Thereby, the essay aims to highlight the challenges in the emerging trend of cross-disciplinary implications, i.e., drug-induced platelet apoptosis, which is a nascent field. Thus, the different mechanisms through which drugs induce platelet apoptosis are discussed, which also opens up a new perspective through which the adverse effects of commonly used drugs could be dealt. The drug-associated platelet toxicity is of grave concern and demands immediate attention. Besides, it would also be appealing to examine the platelet pro-apoptotic effects of other commonly used therapeutic drugs.

6,7-Dimeth-oxy-2,4-di-phenyl-quinoline.

In the title structure of the title compound, C23H19NO2, two conformationally similar mol-ecules (A and B) comprise the asymmetric unit. The dihedral angle between phenyl rings bridged by the quinoline moiety are 76.25 (8)° in mol-ecule A and 70.39 (9)° in mol-ecule B. In the crystal, the independent mol-ecules are connected by C-H⋯O hydrogen bonds and the resulting dimeric aggregates are linked by π-π [inter-centroid distance = 3.7370 (8) Å] and C-H⋯π inter-actions, forming a three-dimensional architecture.

Cyclocondensation of arylhydrazines with 1,3-bis(het)arylmonothio-1,3-diketones and 1,3-bis(het)aryl-3-(methylthio)-2-propenones: synthesis of 1-aryl-3,5-bis(het)arylpyrazoles with complementary regioselectivity.

Two efficient highly regioselective routes for the synthesis of unsymmetrically substituted 1-aryl-3,5-bis(het)arylpyrazoles with complementary regioselectivity starting from active methylene ketones have been reported. In the first protocol, the newly synthesized 1,3-bis(het)aryl-monothio-1,3-diketone precursors (prepared by condensation of active methylene ketones with het(aryl) dithioesters in the presence of sodium hydride) were reacted with arylhydrazines in refluxing ethanol under neutral conditions, furnishing 1-aryl-3,5-bis(het)arylpyrazoles 7, in which the het(aryl) moiety attached to the thiocarbonyl group of monothio-1,3-diketones is installed at the 3-position. In the second method, the corresponding 3-(methylthio)-1,3-bis(het)aryl-2-propenones (prepared in situ by base-induced alkylation of 1,3-monothiodiketones) were condensed with arylhydrazines in the presence of potassium tert-butoxide in refluxing tert-butyl alcohol, yielding 1-aryl-3,5-bis(het)arylpyrazoles 9 with complementary regioselectivity (method A). The efficiency of this protocol was further improved by developing a one-pot, three-component procedure for the synthesis of pyrazoles 9, directly from active methylene ketones, by reacting in situ generated 3-(methylthio)-1,3-bis(het)aryl-2-propenones with arylhydrazines in the presence of sodium hydride (instead of potassium tert-butoxide as base). The structures and regiochemistry of newly synthesized pyrazoles were confirmed from their spectral and analytical data along with X-ray crystallographic data of three pairs of regioisomers.

[4-(4-Meth-oxy-phen-yl)-2-(pyridin-3-yl)-1,3-thia-zol-5-yl][4-(tri-fluoro-meth-yl)phen-yl]methanone.

In the title compound, C23H15F3N2O2S, the thia-zole ring makes dihedral angles of 12.98 (13), 49.30 (11) and 49.83 (12)° with the pyridine ring, the meth-oxy-phenyl ring and the (tri-fluoro-meth-yl)phenyl ring, respectively. In the crystal, mol-ecules are connected via C-H⋯O hydrogen bonds, forming chains along [010]. There are also C-H⋯π and C-F⋯π inter-actions present, forming a three-dimensional structure.

1-(4-Methyl-phenyl-sulfon-yl)-2-{[3-methyl-4-(2,2,2-tri-fluoro-eth-oxy)pyridin-2-yl]methyl-sulfan-yl}-1H-1,3-benzimidazole.

In the title compound, C23H20F3N3O3S2, the benzo-imidazole unit makes dihedral angles of 5.02 (1) and 76.42 (1)°, respectively, with the pyridine and methyl-benzene rings; the dihedral angle between the pyridine and methyl-benzene rings is 72.19 (1)°. In the crystal, mol-ecules are connected by weak C-H⋯F, C-H⋯O and C-H⋯N hydrogen bonds. Weak C-H⋯π inter-actions and π-π stacking [centroid-centroid distance = 3.6485 (14) Å] are also observed. The overall packing shows a three-dimensional architecture. The crystal structure contains a void of 51 Å(3), but no solvent mol-ecule (hexane or ethyl acetate) is located within it.

2-(4-Chloro-phen-yl)-6-methyl-4-(3-methyl-phen-yl)quinoline.

In the title compound, C(23)H(18)ClN, the dihedral angles between the quinoline unit and the chloro-benzene and methyl-benzene rings are 2.57 (9) and 56.06 (9)°, respectively. The crystal structure is stabilized by π-π inter-actions [minimum ring centroid separation = 3.733 (2) Å].

Synthesis and xanthine oxidase inhibitory activity of 7-methyl-2-(phenoxymethyl)-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one derivatives.

An elevated level of blood uric acid (hyperuricemia) is the underlying cause of gout. Xanthine oxidase is the key enzyme that catalyzes the oxidation of hypoxanthine to xanthine and then to uric acid. Allopurinol, a widely used xanthine oxidase inhibitor is the most commonly used drug to treat gout. However, a small but significant portion of the population suffers from adverse effects of allopurinol that includes gastrointestinal upset, skin rashes and hypersensitivity reactions. Moreover, an elevated level of uric acid is considered as an independent risk factor for cardiovascular diseases. Therefore use of allopurinol-like drugs with minimum side effects is the ideal drug of choice against gout. In this study, we report the synthesis of a series of pyrimidin-5-one analogues as effective and a new class of xanthine oxidase inhibitors. All the synthesized pyrimidin-5-one analogues are characterized by spectroscopic techniques and elemental analysis. Four (6a, 6b, 6d and 6f) out of 20 synthesized molecules in this class showed good inhibition against three different sources of xanthine oxidase, which were more potent than allopurinol based on their respective IC(50) values. Molecular modeling and docking studies revealed that the molecule 6a has very good interactions with the Molybdenum-Oxygen-Sulfur (MOS) complex a key component in xanthine oxidase. These results highlight the identification of a new class of xanthine oxidase inhibitors that have potential to be more efficacious, than allopurinol, to treat gout and possibly against cardiovascular diseases.

7-Chloro-5-cyclo-propyl-9-methyl-5H-4,5,6,10-tetra-aza-dibenzo[a,d]cyclo-hepten-11(10H)-one.

In the title compound, C(15)H(13)ClN(4)O, which is a chloro derivative of the drug Nevirapine, the diazepine ring is in a twisted boat conformation. The pyridine rings fused to the diazepine fragment form a dihedral angle of 58.44 (10)° and the mol-ecule adopts a butterfly shape. The mol-ecules are joined via N-H⋯N hydrogen bonding into polymeric chains down the b axis. All weaker C-H⋯O inter-actions involve the carbonyl O atom as acceptor.

Synthesis and identification of a new class of (S)-2,6-diamino-4,5,6,7-tetrahydrobenzo[d]thiazole derivatives as potent antileukemic agents.

Benzothiazoles are multitarget agents with broad spectrum of biological activity. Among the antitumor agents discovered in recent years, the identification of various 2-(4-aminophenyl) benzothiazoles as potent and selective antitumor drugs against different cancer cell lines has stimulated remarkable interest. Some of the benzothiazoles are known to induce cell cycle arrest, activation of caspases and interaction with DNA molecule. Based on these interesting properties of benzothiazoles and to obtain new biologically active agents, a series of novel 4,5,6,7-tetrahydrobenzo[d]thiazole derivatives 5(a-i) were synthesized and evaluated for their efficacy as antileukemic agents in human leukemia cells (K562 and Reh). The chemical structures of the synthesized compounds were confirmed by (1)H NMR, LCMS and IR analysis. The cytotoxicity of these compounds were determined using trypan blue exclusion, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. Results showed that, these compounds mediate a significant cytotoxic response to cancer cell lines tested. We found that the compounds having electron withdrawing groups at different positions of the phenyl ring of the thiourea moiety displayed significant cytotoxic effect with IC(50) value less than 60 microM. To rationalize the role of electron withdrawing group in the induction of cytotoxicity, we have chosen molecule 5g (IC(50) approximately 15 microM) which is having chloro substitution at ortho and para positions. Flow cytometric analysis of annexin V-FITC/ propidium iodide (PI) double staining and DNA fragmentation suggest that 5g can induce apoptosis.

Synthesis of 1-(4-methoxybenzyl)-3-cyclopropyl-1H-pyrazol-5-amine derivatives as antimicrobial agents.

A series of novel substituted 1-(4-methoxybenzyl)-3-cyclopropyl-1H-pyrazol-5-amine benzamides 9(a-h) were synthesized to determine their antibacterial and antifungal activities as well as possible structure-activity relationships (SARs) to improve therapeutic efficacy. The pyrazol-5-amine benzamides were screened for their antibacterial activity against standard strains of Gram-positive (Streptococcus pyogenes NCIM 2608, Staphylococcus aureus ATCC 29737, Bacillus subtilis NCIM 2010) and Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 20852, Klebsiella pneumoniae MTCC 618) bacteria by using streptomycin as positive control. They were also tested for their antifungal activities against mycotoxic strains of Fusarium verticillioides, Aspergillus ochraceous, Aspergillus flavus, Alternaria alternata, and Penicillium chrysogenum using nystatin as positive control. Among the synthesized compounds, 9d, 9g, and 9h showed potent antimicrobial activities.

N-[4-Cyano-3-(trifluoro-meth-yl)phen-yl]-2-eth-oxy-benzamide.

In the title compound, C(17)H(13)F(3)N(2)O(2), the two aromatic rings are essentially coplanar, forming a dihedral angle of 2.78 (12)°. The non-H atoms of the eth-oxy group are coplanar with the attached ring [maximum deviation = 0.271 (3) Å]. An intra-molecular N-H⋯O hydrogen bond occurs. In the crystal structure, mol-ecules are linked by inter-molecular C-H⋯N and C-H⋯F hydrogen bonds.

N-[4-Cyano-3-(trifluoro-meth-yl)phen-yl]-2-meth-oxy-benzamide.

In the title compound, C(16)H(11)F(3)N(2)O(2), the carboxamide group connecting the two aromatic rings is in a syn-periplanar configuration; the mol-ecule is non-planar; the dihedral angle between the two aromatic rings is 13.95 (18)°. Intra-molecular N-H⋯O and C-H⋯O hydrogen bonds occur. In the crystal, mol-ecules are linked by inter-molecular C-H⋯O hydrogen bonds.

Synthesis of novel 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole derivatives as antiproliferative agents: a structure-activity relationship study.

A series of novel 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole derivatives 5(a-m) were synthesized with different substituted aromatic/heterocyclic acid chlorides (R-CO-Cl) and characterized by (1)H NMR, LC/MS, FTIR and elemental analyses. All the compounds synthesised were evaluated for their antiproliferative activity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The antiproliferative effects of the synthesised compounds were tested against viable human skin fibroblast cells and carcinoma cells namely HeLa cells, HT-29 cells, MCF-7 cells, HepG-2 cells by adopting positive and negative control. The importance of the aromatic and heterocyclic moiety was confirmed. From the SAR studies, it reveals that, the substitution at N-terminal of 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole by the heterocyclic ring plays a dominant role and was responsible for the antiproliferative activity. Among the synthesized compounds 5a, 5d and 5k have showed potent antiproliferative activity on all the carcinoma cells tested.

Synthesis and in vitro cytotoxic evaluation of novel diazaspiro bicyclo hydantoin derivatives in human leukemia cells: a SAR study.

To study the structure activity relationship (SAR) on the cytotoxic activity and probe the structural requirement for the potent antitumor activity, a series of novel diazaspiro bicyclo hydantoin derivatives were designed and synthesized. Their structures were confirmed by (1)H NMR, LCMS and IR analyses. The antiproliferative effect of these compounds were determined against human leukemia, K562 (chronic myelogenous leukemia) and CEM (T-cell leukemia) cells using trypan blue and MTT assay, and the SAR associated with the position of N-terminal substituents in diazaspiro bicyclo hydantoin have also been discussed. It has been observed that these compounds displayed strong, moderate and weak cytotoxic activities. Interestingly, compounds having electron withdrawing groups at third and fourth position of the phenyl ring displayed selectively cytotoxic activities to both the cell lines tested with IC(50) value lower than 50 muM. In addition, the cytotoxic activities of the compounds 7(a-o) bearing the substituents at N-3 position of diazaspiro bicyclo hydantoin increases in the order alkene > ester > ether and plays an important role in determining their antitumor activities. The position and number of substituents in benzyl group attached to N-8 of diazaspiro bicyclo hydantoin nucleus interacted selectively with specific targets leading to the difference of biochemical and pharmacological effects.