567-19-1Relevant articles and documents
The thermal sigmatropic isomerization of pseudosaccharyl crotyl ether
Cabral,Maria,Martelo,Eusébio,Cristiano,Fausto
, p. 810 - 815 (2013)
The thermally induced sigmatropic isomerization of the pseudosaccharyl crotyl ether, 3-(E)-but-2- enoxy)-1,2-benzisothiazole 1,1-dioxide (CBID), has been investigated by using temperature dependent infrared spectroscopy, differential scanning calorimetry (DSC), and polarized light thermomicroscopy. The reaction can take place in both melted and crystalline phases, affording the product resulting from the [3,3′] migration of the allylic system from O to N, 2-(E)-1-methylprop-2-en-1,2-benzisothiazol-3(2H)- one 1,1-dioxide (CBIOD). In the melt, the activation energy of the process was determined as being 49.1±5.3 kJ mol-1, with k=(22.2±0.6)×10 4 s-1 at 140 °C. In the solid state, at 110 °C, the rate constant drops by one order of magnitude [k=(1.46±0.07) ×104 s-1]. The enthalpy of reaction, determined by DSC, isΔrxH=-27.0±0.8 kJ mol-1. Assignments were proposed for the infrared spectra of the observed neat condensed phases of the two compounds.
Synthesis, Structure, and Cytotoxicity of a New Sulphanyl-Bridged Thiadiazolyl-Saccharinate Conjugate: The Relevance of S???N Interaction
Cabral, Lília I. L.,Brás, Elisa M.,Henriques, Marta S. C.,Marques, Catia,Frija, Luís M. T.,Barreira, Luísa,Paix?o, José António,Fausto, Rui,Cristiano, Maria Lurdes S.
, p. 3251 - 3262 (2018)
Reports showing that the copper concentration is considerably higher in neoplasms than in normal tissues prompted the need to develop selective copper chelators. We disclosed recently that some N-linked tetrazole-saccharinates bind selectively to copper, forming complexes that are highly cytotoxic towards cancer cells. Because tetrazole-saccharinates are photolabile, due to the photoreactivity of tetrazoles, we proposed thiadiazolyl-saccharinates as an alternative. Herein we describe the synthesis, structure, and monomeric photochemistry of a sulphanyl-bridged thiadiazolyl-saccharinate, 3-[(5-methyl-1,3,4-thiadiazol-2-yl)sulphanyl]-1,2-benzothiazole 1,1-dioxide (MTSB). The monomeric structure, charge density analysis, and characteristic infrared spectrum of MTSB were investigated theoretically, using quantum chemical calculations, and also experimentally, using matrix-isolation infrared spectroscopy. The crystal structure was investigated by combining X-ray crystallography with infrared and Raman spectroscopies. Results show that the structure of isolated MTSB is similar to that found in the crystal, with an S???N interaction clearly contributing to the structure of the molecule and of the crystal. Matrix irradiation revealed a high photostability of MTSB, compared to parent tetrazole-saccharinates and to the 5-methyl-1,3,4-thiadiazole building block, emphasizing the photostabilizing effect of the saccharyl system. Finally, in vitro toxicity assays of MTSB showed a copper concentration-dependent toxicity against cancer cells, without affecting normal cells. In particular, MTSB was most effective towards the hepatic (HepG2), neuroblastoma (SH-SY5), and lymphoma cell lines (U937). Thus, MTSB represents a promising lead for cancer chemotherapy based on chelating agents.
Structure and photochemistry of a saccharyl thiotetrazole
Ismael,Borba,Henriques,Paix?o,Fausto,Cristiano
, p. 392 - 400 (2014)
The molecular structure and photochemistry of 5-thiosaccharyl-1-methyltetrazole (TSMT) were studied by means of matrix-isolation FTIR spectroscopy, X-ray crystallography, and theoretical calculations. The calculations predicted two conformers of TSMT that differ in energy by more than 15 kJ mol-1. The infrared spectrum of TSMT isolated in solid argon was fully assigned on the basis of the spectrum calculated (O3LYP/6-311++G(3df,3pd)) for the most stable conformer. In the crystal, TSMT molecules were found to assume the same conformation as for the isolated molecule, with each molecule forming four hydrogen bonds with three neighboring molecules, leading to a network of TSMT oligomers. Upon UV (λ = 265 nm) irradiation of the matrix-isolated TSMT, two photodegradation pathways were observed, both arising from cleavage of the tetrazolyl ring. Pathway a involves cleavage of the N1-N2 and N3-N4 bonds with extrusion of N2, leading to photostable diazirine and thiocarbodiimide derivatives. The photostability of the photoproduced diazirine under the conditions used precluded its rearrangement to the nitrile imine, as reported for 5-phenyltetrazole by Bégué et al. (J. Am. Chem. Soc. 2012, 134, 5339). Pathway b involves cleavage of the C5-N1 and N4-N3 bonds, leading to a thiocyanate and methyl azide, the latter undergoing subsequent fragmentation to give CNH.
On the development of selective chelators for cadmium: Synthesis, structure and chelating properties of 3-((5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)amino)benzo [d]isothiazole 1,1-dioxide, a novel thiadiazolyl saccharinate
Amado, Patrícia S. M.,Barreira, Luísa,Cristiano, Maria L. S.,Fernandes, André L.,Guerreiro, Bruno,Leal, Joana F.,Paix?o, José A.
, (2021)
Aquatic contamination by heavy metals is a major concern for the serious negative con-sequences it has for plants, animals, and humans. Among the most toxic metals, Cd(II) stands out since selective and truly efficient methodologies for its removal are not known. We report a novel multidentate chelating agent comprising the heterocycles thiadiazole and benzisothiazole. 3-((5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)amino)benzo[d]isothiazole 1,1-dioxide (AL14) was syn-thesized from cheap saccharin and characterized by different techniques, including single crystal X-ray crystallography. Our studies revealed the efficiency and selectivity of AL14 for the chelation of dissolved Cd(II) (as compared to Cu(II) and Fe(II)). Different spectral changes were observed upon the addition of Cd(II) and Cu(II) during UV-Vis titrations, suggesting different complexation interactions with both metals.
Discovery of a Potent and Orally Bioavailable Hypoxia-Inducible Factor 2α (HIF-2α) Agonist and Its Synergistic Therapy with Prolyl Hydroxylase Inhibitors for the Treatment of Renal Anemia
Yu, Yancheng,Yang, Fulai,Yu, Quanwei,Liu, Simeng,Wu, Chenyang,Su, Kaijun,Yang, Le,Bao, Xiaoqian,Li, Zhihong,Li, Xiang,Zhang, Xiaojin
, p. 17384 - 17402 (2021/11/16)
Activation of hypoxia-inducible factor 2 (HIF-2) has emerged as a potent renal anemia treatment strategy. Here, the benzisothiazole derivative 26 was discovered as a novel HIF-2α agonist, which first demonstrated nanomolar activity (EC50 = 490 nM, Emax = 349.2%) in the luciferase reporter gene assay. Molecular dynamics simulations indicated that 26 could allosterically enhance HIF-2 dimerization. Furthermore, compound 26 had a good pharmacokinetic profile (the oral bioavailability in rats was 41.38%) and an in vivo safety profile (the LD50 in mice was greater than 708 mg·kg-1). In the in vivo efficacy assays, the combination of 26 and the prolyl hydroxylase inhibitor, AKB-6548, was confirmed for the first time to synergistically increase the plasma erythropoietin level in mice (from 260 to 2296 pg·mL-1) and alleviate zebrafish anemia induced by doxorubicin. These results provide new insights for HIF-2α agonists and the treatment of renal anemia.
Synthesis, characterization and antimicrobial evaluation of new 3-(Alkyl/Arylamino)benzo[d]isothiazole 1,1-derivatives
Kamble, Dhanraj P.,Shankarwar, Anil G.,Mane, Yogesh D.,Tigote, Radhakrishna M.,Sarnikar, Yuvaraj P.,Madje, Balaji R.
, p. 797 - 804 (2021/09/08)
The saccharine nucleus has long been recognized as a significant component in medicine. A series of pseudo-saccharine amines derivatives (7a-j) were synthesized and examined for their antibacterial activity. After testing all compounds, 7b, 7f, 7g, 7i and 7j were found most effective against Escherichia coli, Streptococcus aureus and Bacillus subtilis strains. The MIC of the compound was found from 4.6 to 16.1 μM. Further, compound 7f and 7i exhibited excellent activity against E.coli and Bacillus subtilis with MIC value 4.6 and 4.7 μM respectively. The compound 7b and 7i was found active against all the three bacteria. The zone inhibition was observed at 10 μM against Escherichia coli, Staphylococcus aureus and Bacillus subtilis at 0.9, 1.8, 3.9 respectively for 7b and 1.0, 1.8 and 2.0 cm respectively for 7i.
Insight into the binding mode of HIF-2 agonists through molecular dynamic simulations and biological validation
Yu, Yancheng,Yu, Quanwei,Liu, Simeng,Wu, Chenyang,Zhang, Xiaojin
, (2020/11/20)
Hypoxia-inducible factor-2 (HIF-2), a heterodimeric transcriptional protein consisting of HIF-2α and aryl hydrocarbon receptor nuclear translocator (ARNT) subunits, has a broad transcriptional profile that plays a vital role in human oxygen metabolism. M1001, a HIF-2 agonist identified by high-throughput screening (HTS), is capable of altering the conformation of Tyr281 of the HIF-2α PAS-B domain and enhancing the affinity of HIF-2α and ARNT for transcriptional activation. M1002, an analog of M1001, shows improved efficacy than M1001. However, the cocrystal structure of M1001 and HIF-2 has some defects in revealing the agonist binding mode due to the relatively low resolution, while the binding mode of M1002 remained unexplored. To in-depth understand agonist binding profiles, herein, the molecular dynamic (MD) simulations was applied to construct a stable agonist-protein model, and a possible binding mode was proposed through the analysis of the binding free energy and hydrogen bonding of the simulation results. Nine compounds were then synthesized and evaluated to verify the proposed binding mode. Among them, compound 10 manifested improved agonistic activity and reduced toxicity compared to M1002. This study provides deep insight into the binding mode of such HIF-2 agonists, which would be useful for designing novel agonists for HIF-2.
Design, synthesis and in silico insights of new 7,8-disubstituted-1,3-dimethyl-1H-purine-2,6(3H,7H)-dione derivatives with potent anticancer and multi-kinase inhibitory activities
Abdel Gawad, Nagwa M.,El Kerdawy, Ahmed M.,George, Riham F.,Georgey, Hanan H.,Mohamed, Abdalla R.
, (2021/01/04)
Aiming to obtain an efficient anti-proliferative activity, structure- and ligand-based drug design approaches were expanded and utilized to design and refine a small compound library. Subsequently, thirty-two 7,8-disubstituted-1,3-dimethyl-1H-purine-2,6(3H,7H)-dione derivatives were selected for synthesis based on the characteristic pharmacophoric features required for PI3K and B-Raf oncogenes inhibition. All the synthesized compounds were evaluated for their in vitro anticancer activity. Compounds 17 and 22c displayed an acceptable potent activity according to the DTP-NCI and were further evaluated in the NCI five doses assay. To validate our design, compounds with the highest mean growth inhibition percent were screened against the target PI3Kα and B-RafV600E to confirm their multi-kinase activity. The tested compounds showed promising multi-kinase activity. Compounds 17 and 22c anticancer effectiveness and multi-kinase activity against PI3Kα and B-RafV600E were consolidated by the inhibition of B-RafWT, EGFR and VEGFR-2 with IC50 in the sub-micromolar range. Further investigations on the most potent compounds 17 and 22c were carried out by studying their safety on normal cell line, in silico profiling and predicted ADME characteristics.
Versatile new reagent for nitrosation under mild conditions
Galloway, Jordan D.,Sarabia, Cristian,Fettinger, James C.,Hratchian, Hrant P.,Baxter, Ryan D.
supporting information, p. 3253 - 3258 (2021/05/06)
Here we report a new chemical reagent for transnitrosation under mild experimental conditions. This new reagent is stable to air and moisture across a broad range of temperatures and is effective for transnitrosation in multiple solvents. Compared with traditional nitrosation methods, our reagent shows high functional group tolerance for substrates that are susceptible to oxidation or reversible transnitrosation. Several challenging nitroso compounds are accessed here for the first time, including 15N isotopologues. X-ray data confirm that two rotational isomers of the reagent are configurationally stable at room temperature, although only one isomer is effective for transnitrosation. Computational analysis describes the energetics of rotamer interconversion, including interesting geometry-dependent hybridization effects.
Preparation method and medical application of benzisothiazole and benzothiophene
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Paragraph 0098; 0102, (2021/08/19)
The invention discloses a preparation method and medical application of benzisothiazole and benzothiophene, and telates to the field of pharmaceutical chemistry. According to the invention, benzisothiazole and benzothiophene are the first type of HIF-2 agonists; compared with a compound M1001 found by the applicant in the earlier stage, the invention has better HIF-2 agonist activity, and has remarkable enhancement activity on expression of mRNA and protein of EPO, VGEF, Glut1, NDRG1 and the like at the downstream of HIF-2, so that the invention can be used for preparing drugs for treating and/or preventing chronic kidney diseases/chronic renal anemia, dyslipidemia and high cholesterol caused by abnormal expression of HIF-2; and the method has a good industrialization prospect.
