Synthesis of 1,2-benzisoxazole tethered 1,2,3-triazoles that exhibit anticancer activity in acute myeloid leukemia cell lines by inhibiting histone deacetylases, and inducing p21 and tubulin acetylation

1,2,3-Triazole-based heterocycles have previously been shown to possess significant anticancer activity in various tumor models. In the present study, we attached a 1,2,3-triazole moiety to the third position of a 1,2-benzisoxazole heterocycle via copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) with various alkynes and established for the title compounds significant antiproliferative effect against human acute myeloid leukemia (AML) cells. Among the tested compounds, 3-(4-(4-phenoxyphenyl)-1H-1,2,3-triazol-1-yl)benzodisoxazole (PTB) was found to be the most potent antiproliferative agent with an IC50 of 2 μM against MV4-11 cells using MTT assay. Notably, PTB induced cytotoxicity in MOLM13, MOLM14 and MV4-11 cells with selectivity over normal bone marrow cells (C57BL/6). Furthermore, PTB was found to induce cytotoxicity by increasing apoptosis of AML cells (MOLM13, MOLM14 and MV4-11) as well as sub-G1 cell population and apoptotic cells at submicromolar concentrations, as shown by flow cytometry and Annexin-V staining, respectively. On the protein level we suggested histone deacetylases (HDACs) as the potential protein target of those compounds in silico, and the predicted target was next experimentally validated by measuring the variations in the levels of p21, cyclin D and acetylation of histone H3 and tubulin. Molecular docking analysis of the title compounds with the second deacetylase domain of HDAC6 displayed high degree of shape complementarity to the binding site of the enzyme, forming multiple molecular interactions in the hydrophobic region as well as a hydrogen bond to the phenol side-chain of Tyr-782. Thus, 1,2,3-triazole derivatives appear to represent a class of novel, biologically active ligands against histone deacetylases which deserve to be further evaluated in their applications in the cancer field. © 2015 Elsevier Ltd. All rights reserved

Anti-tumor and anti-angiogenic activity of novel hydantoin derivatives: Inhibition of VEGF secretion in liver metastatic osteosarcoma cells

A series of new azaspiro bicyclic hydantoin derivatives has been designed and synthesized. Initially, the anti-proliferative effect of the hydantoin derivatives was evaluated against human ovarian cancer cells (SKOV-3 and OVSAHO) and murine osteosarcoma cells (LM8 and LM8G7). Among the tested compounds, 8-(3-fluorobenzyl)-1′-(4-(methylsulfonyl)benzyl)-8-azaspiro[bicyclo[3.2.1]octane-3,4′-imidazolidine]-2′,5′-dione (7h) and 8-(3,4-difluorobenzyl)-1′-(4-(methylsulfonyl)benzyl)-8-azaspiro[bicyclo[3.2.1]octane-3,4′-imidazolidine]-2′,5′-dione (7i) showed a significant anti-proliferative activity against the OVSAHO and LM8G7 cells. The real-time monitoring of the effect of the compounds 7h and 7i against the proliferation of LM8G7 was revealed that resulting IC50 values were 102 μM and 13 μM, respectively. We reasoned that the presence of fluorine atom at the 3rd position of the phenyl ring of the hydantoin side chain may determine the potency of the molecule. Furthermore, the compound 7i inhibited the tube formation of the mouse endothelial cells. Finally, the treatment of the compound 7i against the proliferation of LM8G7 cells demonstrated the down regulation of the secretion of VEGF, indicate the potential angioinhibitory effects. In conclusion, our findings demonstrate the suppression of the secretion of VEGF by LM8G7 cells by the compound 7i might contribute at least in part to the antitumor action

Synthesis and characterization of novel oxazines and demonstration that they specifically target cyclooxygenase 2

In the present study, we used solution combustion synthesis-bismuth oxide (Bi2O3) as catalyst for the simple and efficient synthesis of 1,2-oxazine based derivatives of 6-fluoro-3-(piperidin-4-yl)benzo[d]isoxazoles, 1-arylpiperazine and carbazoles. (4aR,8aR)-4-(4-Methoxyphenyl)-3-((4-(4-methoxyphenyl)piperazin-1-yl)methyl)-4a,5,6,7,8,8a-hexahydro-4H-benzo[e][1,2]oxazine was found to be the most potent compound with a high degree of selectivity in inhibition towards COX2 (1.7 μM) over COX1 (40.4 μM) demonstrating the significance of 1,2-oxazine derivatives in developing COX2 specific inhibitors. Molecular docking analyses demonstrated that an isoleucine residue in the active site of COX1 is responsible for lower affinity to COX1 and increased potency towards COX2. Overall, our study reveals that the new 1,2-oxazine-based small molecules qualify as lead structures in developing COX2-specific inhibitors for anti-inflammatory therapy

Hydrophobic interaction of 2-trifluoromethyl-N 10-substituted phenoxazines with bovine serum albumin and reversal of drug resistance in bacterial cells

Objective: The objective of this study was to report the hydrophobic interaction of 2-trifluoromethyl-N10 Methods: Binding of six compounds, 10-3-substituted phenoxazines with bovine serum albumin and reversal of drug resistance in bacterial cells. '-N-morpholinopropyl-2-trifluoromethyl phenoxazine (1C), 10-4'-N-morpholinobutyl-2-trifluoromethyl phenoxazine (2C), 10-3'-N-pyrrolidinopropyl-2-trifluoromethyl phenoxazine (3C), 10-4'-N-pyrrolidinobutyl-2-trifluoromethyl phenoxazine (4C), 10-N-piperidinoacetyl-2-trifluoromethyl phenoxazine (5C), and 10-N-pyrrolidinoacetyl-2-trifluoromethyl phenoxazine (6C), to bovine serum albumin (BSA) has been measured by gel filtration and equilibrium dialysis methods. The binding of these compounds to BSA has been characterized by percentage of bound drug (β), the association constant (K), the apparent binding constant (k) and free energy (�Fo Results: The results of displacing experiments reveal that the phenoxazine benzene rings and tertiary amines attached to the side chain of phenoxazine moiety are bound to a hydrophobic region on the albumin molecule. Among the compounds examined the butyl series seems to possess better reversing ability, suggesting that the activity could be related to lipophilicity and the extent of binding to BSA.). The binding of phenoxazine derivatives to BSA, a serum protein that binds and transports small molecules, is correlated with their partition coefficients. Further, the ability of the phenoxazines (1C-6C) on the antibacterial activity of five antibiotics, kanamycin, spectinomycin, gentamycin, streptomycin and benzylpenicillin was examined for their ability to reverse the resistance of E. coli K12 MG 1655 and E. coli ST 58. Conclusions: Phenoxazines are bound to albumin by hydrophobic interactions of their benzene rings. The alkyl side chain, particularly butyl chain of phenoxazines intensifies the interaction of phenoxazines with BSA. The compound that binds to a greater extent with protein possesses more activity for reversing of drug resistance. © 2015, International Journal of Pharmacy and Pharmaceutical Science. All right resurved

A small oxazine compound as an anti-tumor agent: A novel pyranoside mimetic that binds to VEGF, HB-EGF, and TNF-α

A novel pyranoside mimetic compound, DMBO (2-(2,6-difluorophenyl)-5-(4-methoxyphenyl)-1-oxa-3-azaspiro5.5undecane), was designed and synthesized. The sugar mimicking behavior of DMBO was addressed by its ability to bind several growth factors/cytokines such as vascular endothelial growth factor (VEGF), heparin-binding epidermal growth factor-like growth factor (HB-EGF), and tumor necrosis factor (TNF)-α as demonstrated by the recently developed surface plasmon resonance assay. DMBO exhibited strong anti-proliferation activity in vitro against tumor cells including a highly metastatic murine osteosarcoma cell line LM8G7 that secretes VEGF as well as two human ovarian cell lines, OVSAHO and SKOV-3, which secrete TNF-α and HB-EGF respectively. Furthermore, DMBO inhibited the metastatic activity to the mouse liver of LM8G7 cells injected from a lateral tail vein, and affected the heparan-degrading activity of LM8G7 cells. Here, we report that DMBO acts as a human heparanase inhibitor in vitro possibly as a substrate mimetic. DMBO also inhibited the migration and invasion of LM8G7 cells and angiogenic events such as endothelial cell proliferation, migration and capillary tube-like formation in vitro. More prominently, the administration of DMBO with heparin resulted in synergistic anti-tumor effects in mouse model. of. osteosarcoma. These preclinical data shows the potential anti-cancer effects of DMBO. © 2010 Elsevier Ireland Ltd

Synthesis and characterization of novel 1,2-oxazine-based small molecules that targets acetylcholinesterase

Thirteen 2-oxazine-based small molecules were synthesized targeting 5-lipoxygenase (LOX), and acetylcholinesterase (AChE). The test revealed that the newly synthesized compounds had potent inhibition towards both 5-LOX and AChE in lower micro molar concentration. Among the tested compounds, the most active compound, 2-(2-acetyl-6,6-dimethyl-4-phenyl-5,6-dihydro-2H-1,2-oxazin-3- yl)methyl-1H-isoindole-1,3(2H)-dione (2a) showed inhibitory activity towards 5-LOX and AChE with an IC50 values of 1.88, and 2.5 μM, respectively. Further, the in silico molecular docking studies revealed that the compound 2a bound to the catalytic domain of AChE strongly with a highest CDOCKER score of -1.18 kcal/mol when compared to other compounds of the same series. Additionally, 2a showed a good lipophilicity (log P = 2.66), suggesting a potential ability to penetrate the blood-brain-barrier. These initial pharmacological data revealed that the compound 2a could serve as a drug-seed in developing anti-Alzheimer's agents. © 2014 Elsevier Ltd. All rights reserved

Molprint 2D-Based Identification and Synthesis of Novel Chromene Based Small Molecules that Target Pla2: Validation through Chemo-And Bioinformatics Approaches

Phospholipase A2 (PLA2) is known to regulate inflammation and hence it is considered as a validated drug-target by medicinal chemists. In this report, we have identified and considered a highly ranked ligand from the ZINC-drug-like compounds database that targets PLA2 via the MOLPRINT-2D based chemoinformatics drug-design approach. The computationally predicted lead molecule was found to contain a core moiety of a chromene ring, which is well known for its varied biological properties. Here, a novel and efficient retro-synthetic protocol for the synthesis of highly substituted chromene libraries was made. A one-pot synthesis of chromene was carried out using different aromatic primary alcohols, malononitrile and 4-hydroxy coumarin in the presence of a mild oxidant mixture called T3P®–DMSO, followed by a Suzuki coupling reaction to obtain the lead molecules. All of the tested compounds of the chromene series displayed inhibition of the venom PLA2 in the range of 12 to 68 μM. Among the tested compounds, 2-amino-4-(2′-methyl-[1,1′-biphenyl]-4-yl)-5-oxo-4,5-dihydropyrano[3,2-c]chromene-3-carbonitrile (7b) showed maximum inhibitory efficacy against venom PLA2 with an IC50 value of 12.5 μM. Furthermore, the designed PLA2 ligands bound to the active site of venom PLA2, whose binding affinity was comparable to nimesulide, indicating that the chromene moiety containing ligands could be novel lead-structures that serve as anti-inflammatory agents

Adamantyl-tethered-biphenylic compounds induce apoptosis in cancer cells by targeting Bcl homologs

Bcl homologs prominently contribute to apoptotic resistance in cancer cells and serve as molecular targets in treatment of various cancers. Herein, we report the synthesis of biphenyl-adamantane derivatives by a ligand free palladium on carbon based Suzuki reaction using diisopropylamine as a base for the coupling of adamantane based aryl chloride with a variety of aryl boronic acids. Among the biphenyl derivatives synthesized, compound 3'-(adamantan-1-yl)-4'-methoxy-1,1'-biphenyl-3-ol (AMB) displayed cytotoxic activity against hepatocellular carcinoma cell lines without significantly affecting the normal cell lines. Further, AMB caused increased accumulation of the HCC cells in subG1 phase, decreased the expression of Bcl-2, Bcl-xL, cyclin D1, caspase-3, survivin and increased the cleavage of PARP in a time-dependent manner. In silico molecular interaction studies between Bcl homologs and AMB showed that the biphenyl scaffold is predicted to form �-� interactions with Phe-101 and Tyr-105 and the adamantyl fragment is predicted to occupy another hydrophobic region in the kink region of the binding groove. In summary, we report on the synthesis and biological characterization of adamantyl-tethered biphenylic compounds that induce apoptosis in tumor cells most likely by targeting Bcl homologs. © 2015 Elsevier Ltd

A Nano-Mgo and Ionic Liquid-Catalyzed ‘Green’ Synthesis Protocol for the Development of Adamantyl-Imidazolo-Thiadiazoles as Anti-Tuberculosis Agents Targeting Sterol 14α-Demethylase (CYP51)

In this work, we describe the ‘green’ synthesis of novel 6-(adamantan-1-yl)-2-substitutedimidazo[2,1-b][1,3,4]thiadiazoles (AITs) by ring formation reactions using 1-(adamantan-1-yl)-2-bromoethanone and 5-alkyl/aryl-2-amino1,3,4-thiadiazoles on a nano material base inionic liquid media. Given the established activity of imidazothiadiazoles against M. tuberculosis,we next examined the anti-TB activity of AITs against the H37Rv strain using Alamarblue assay. Among the tested compounds 6-(adamantan-1-yl)-2-(4-methoxyphenyl)imidazo[2,1-b][1,3,4]thiadiazole (3f) showed potent inhibitory activity towards M. tuberculosis with an MIC value of 8.5 μM. The inhibitory effect of this molecule against M. tuberculosis was comparable to the standard drugs such as Pyrazinamide, Streptomycin, and Ciprofloxacin drugs. Mechanistically, an in silico analysis predicted sterol 14α-demethylase (CYP51)as the likely target and experimental activity of 3f in this system corroborated the in silico target prediction. In summary, we herein report the synthesis and biological evaluation of novel AITs against M. tuberculosis that likely target CYP51 to induce their antimycobacterial activity