6154-04-7Relevant articles and documents
Synthesis and antileishmanial activity of 1,2,4,5-tetraoxanes against leishmania donovani
Cabral, Lília I.L.,Pomel, Sébastien,Cojean, Sandrine,Amado, Patrícia S.M.,Loiseau, Philippe M.,Cristiano, Maria L.S.
supporting information, (2020/02/11)
A chemically diverse range of novel tetraoxanes was synthesized and evaluated in vitro against intramacrophage amastigote forms of Leishmania donovani. All 15 tested tetraoxanes displayed activity, with IC50 values ranging from 2 to 45 μm. The most active tetraoxane, compound LC140, exhibited an IC50 value of 2.52 ± 0.65 μm on L. donovani intramacrophage amastigotes, with a selectivity index of 13.5. This compound reduced the liver parasite burden of L. donovani-infected mice by 37% after an intraperitoneal treatment at 10 mg/kg/day for five consecutive days, whereas miltefosine, an antileishmanial drug in use, reduced it by 66%. These results provide a relevant basis for the development of further tetraoxanes as effective, safe, and cheap drugs against leishmaniasis.
Solvent-free oxidation of benzyl alcohols catalysed by a tetrazole-saccharinate Zn(II) complex under microwave radiation: The role of the ligand and the reaction mechanism
Cristiano, M. Lurdes S.,Fernandes, André L.,Frija, Luís M. T.,Pombeiro, Armando J. L.
, (2020/07/27)
Herein we present an efficient methodology for the microwave-assisted peroxidative oxidation of benzyl alcohols to the corresponding aldehydes by using a novel and stable tetrazole-saccharinate zinc(II) catalyst, along with some insights into the reaction mechanism. This methodology is distinguished by the use of easily available and cheap reagents on the genesis of the zinc catalyst, mild reaction conditions, very short reaction periods (5–20 min) and no need to add an organic solvent. Furthermore, the use of TBHP (70percent. aq.) as oxidizing agent turn this protocol a convenient one for benzyl alcohol oxidation in yields up to 98percent.
NEW ENDOPEROXIDE COMPOUNDS, PROCESS FOR OBTAINING THEM AND USES THEREOF FOR CONTROL OF PERKINSIOSIS IN BIVALVES
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Page/Page column 22-23, (2020/12/11)
The present invention relates to new endoperoxide compounds and compositions, and to a process for producing them for prophylaxis and control of perkinsiosis in bivalves. Endoperoxide compounds with biological activity against Perkinsus olseni include 13
Preparation and characterization of bis(guanidinium) and bis(aminotetrazolium)dodecahydroborate salts: Green high energy nitrogen and boron rich compounds
Sharon, Pessia,Afri, Michal,Mitlin, Sergey,Gottlieb, Levi,Schmerling, Bruria,Grinstein, Dan,Welner, Shmuel,Frimer, Aryeh A.
, p. 71 - 89 (2018/10/20)
This paper describes the syntheses, crystallization, characterization and energetic properties (calorimetry) of closo-dodecahydroborate salts with guanidinium and aminotetrazolium based cations. The salts were readily produced in good yields by metathesis (ion exchange) reactions depending on the water solubility of the dodecahydroborate salts. Water insoluble salts can be synthesized from the potassium or sodium salts by a simple metathesis reaction with the corresponding halide of the desired organic cation. Water soluble salts can be prepared via two consecutive metathesis reactions: the halide is first converted to the corresponding sulfate, which is reacted in turn with barium dodecahydroborate, yielding the water soluble organic closo(B12H12)2? salt and the insoluble BaSO4. The product salt is conveniently isolated by water evaporation. The aminotetrazolium salt 12d gives nice crystals when recrystallized from DMF and NMP but incorporate solvent. Guanidinium salt 15a recrystallizes from nicely from water as a monohydrate. Thermogravimetric analyses established the thermal stabilities of these compounds. The enthalpies of combustion of representative salts were determined using a constant volume bomb calorimetry. The data shows that these salts possess relatively high heats of combustion (ΔUc, ca. 35 kJ·g?1), and have the potential to serve as green high-energy materials.
In vitro assessment of antimicrobial, antioxidant, and cytotoxic properties of saccharin–tetrazolyl and –thiadiazolyl derivatives: The simple dependence of the ph value on antimicrobial activity
Frija, Luís M. T.,Ntungwe, Epole,Sitarek, Przemys?aw,Andrade, Joana M.,Toma, Monika,?liwiński, Tomasz,Cabral, Lília,Cristiano, M. Lurdes S.,Rijo, Patrícia,Pombeiro, Armando J. L.
, (2019/11/20)
The antimicrobial, antioxidant, and cytotoxic activities of a series of saccharin–tetrazolyl and –thiadiazolyl analogs were examined. The assessment of the antimicrobial properties of the referred-to molecules was completed through an evaluation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against Gram-positive and Gram-negative bacteria and yeasts. Scrutiny of the MIC and MBC values of the compounds at pH 4.0, 7.0, and 9.0 against four Gram-positive strains revealed high values for both the MIC and MBC at pH 4.0 (ranging from 0.98 to 125 μg/mL) and moderate values at pH 7.0 and 9.0, exposing strong antimicrobial activities in an acidic medium. An antioxidant activity analysis of the molecules was performed by using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, which showed high activity for the TSMT (N-(1-methyl-2H-tetrazol-5-yl)-N-(1,1-dioxo-1,2-benzisothiazol-3-yl) amine, 7) derivative (90.29% compared to a butylated hydroxytoluene positive control of 61.96%). Besides, the general toxicity of the saccharin analogs was evaluated in an Artemia salina model, which displayed insignificant toxicity values. In turn, upon an assessment of cell viability, all of the compounds were found to be nontoxic in range concentrations of 0–100 μg/mL in H7PX glioma cells. The tested molecules have inspiring antimicrobial and antioxidant properties that represent potential core structures in the design of new drugs for the treatment of infectious diseases.
2-Methyl-substituted monotetrazoles in copper(ii) perchlorate complexes: manipulating coordination chemistry and derived energetic properties
Zeisel, Lukas,Szimhardt, Norbert,Wurzenberger, Maximilian H. H.,Klap?tke, Thomas M.,Stierstorfer, J?rg
supporting information, p. 609 - 616 (2019/01/10)
A proposed correlation between coordination chemistry and deduced energetic properties (thermal behaviour, and sensitivities towards mechanical and optical stimuli) of copper(ii) complexes is investigated. Starting from a system comprising Cu(ClO4)2 and either of the ligands 2-methyl-5-aminotetrazole (1, 2-MAT) or 2-methyl-5H-tetrazole (2, 2-MTZ), typically altered parameters like the metal(ii) centre, ligand, or counterion were predefined. Instead, solely slight changes in ligand concentration and the solvent system were implemented in order to provide an insight into structure-property relationships of energetic coordination compounds (ECC) of this type. As a result, five highly energetic complexes [Cu(H2O)2(2-MAT)4](ClO4)2·H2O (3), [Cu(H2O)2(2-MAT)4](ClO4)2 (4), [Cu(H2O)2(2-MAT)4](ClO4)2·2 2-MAT (5), [Cu(ClO4)2(H2O)2(2-MAT)2] (6), and [Cu(H2O)2(2-MTZ)4](ClO4)2 (7) were synthesized and, except for 5, elaborately characterized. Besides structural elucidation via X-ray diffraction, NIR-spectroscopy, differential thermal analysis (DTA), standard sensitivity measurements (impact, friction, and electrostatic discharge), UV/vis-spectroscopy, and optical initiation experiments were conducted to deduce a precise relationship between coordination chemistry and the consequential energetic characteristics of these complexes.
Substituent-dependent coordination modes of 1-methyl-5-R-tetrazoles in their cupric chloride complexes
Voitekhovich, Sergei V.,Lyakhov, Alexander S.,Matulis, Vadim E.,Ivashkevich, Ludmila S.,Ivashkevich, Oleg A.
, p. 100 - 110 (2019/02/19)
A series of cupric chloride complexes with 1-methyl-5-R-tetrazole ligands, where R = NH2, t-Bu, Ph, MeS, CH[dbnd]CH2, MeSO2, were synthesized by interaction of CuCl2·2H2O with the above ligands LNH2, LtBu, LPh, LMeS, LVin, and LMeSO2, respectively. The obtained complexes [Cu(LNH2)3Cl2]·H2O (1), [Cu(LtBu)2Cl2] (2), [Cu(LPh)2Cl2] (3), [Cu(LMeS)2Cl2] (4), [Cu(LVin)Cl2]n (5), and [Cu(LMeSO2)(H2O)Cl2]n (6) were characterized by single crystal X-ray analysis. The effect of C5-substituent on coordination modes of tetrazole ligands and structural motifs of complexes was observed. Complexes 1–4 are mononuclear, with the tetrazole ring N4 coordination. Complex 5 presents 1D coordination polymer, formed at the expense of triple bridge between two neighboring copper(II) cations (double chlorido bridge and the tetrazole ring N3,N4-bridge). In 6, being also 1D coordination polymer, coordination chains are composed of alternating Cu(LMeSO2)2 and Cu(H2O)2 fragments linked by double chlorido bridges. Ligand LMeSO2 shows N3 coordination, being rare among 1,5-disubstituted tetrazoles. The influence of the nature of C5 substituents on coordination features of the obtained complexes is discussed by using quantum-chemical calculations of the electronic structure and basicity of the ligands.
Copper(II) and cobalt(II) tetrazole-saccharinate complexes as effective catalysts for oxidation of secondary alcohols
Frija, Luís M.T.,Alegria, Elisabete C.B.A.,Sutradhar, Manas,Cristiano, M. Lurdes S.,Ismael, Amin,Kopylovich, Maximilian N.,Pombeiro, Armando J.L.
, p. 283 - 290 (2016/11/04)
Mononuclear Cu(II) and Co(II) complexes comprising 2-methyltetrazole-saccharinate bidentate N,N-chelating ligand have been synthesized for the first time and tested as homogeneous catalysts for oxidation of secondary alcohols in a solvent-free and microwave assisted protocol using aqueous tert-butyl hydroperoxide (TBHP) as oxidant. The developed catalytic system exhibits broad functional group compatibility, allowing efficient and selective conversion of a variety of secondary alcohols, including allylic ones, into the corresponding ketones. With typical 0.2 mol% content of the catalyst and under 20–50 W microwave irradiation, most reactions are complete within 10 min, presenting TONs up to 5.5 × 102 and TOFs up to 1.1 × 104 h?1. No additives and co-oxidants have been used, while TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxyl) acts as inhibitor in most cases. A plausible reaction mechanism involving the new catalytic systems is outlined.
An Environmentally Friendly Method for N-Methylation of 5-Substituted 1H-Tetrazoles with a Green Methylating Reagent: Dimethyl Carbonate
Xie, Aming,Zhang, Qiang,Liu, Yangyang,Feng, Liandong,Hu, Xinyu,Dong, Wei
, p. 1483 - 1487 (2015/10/06)
An environmentally friendly method was established for the N-methylation of the 5-substituted 1H-tetrazoles with a green reagent: DMC. DABCO was the optimal catalyst, and hazardous chemicals were avoided in this protocol. A plausible catalytic mechanism is proposed, which consists of a DABCO-activated process and a thermally induced rearrangement of tetrazole carbamates.
Molecular structure of nitrogen-linked methyltetrazole-saccharinates
Ismael, Amin,Paix?o, José António,Fausto, Rui,Cristiano, Maria Lurdes S.
experimental part, p. 128 - 142 (2012/10/08)
The molecular structures of nitrogen-linked 1- and 2-methyltetrazole- saccharinates, were investigated in the crystalline phase using X-ray crystallography and infrared and Raman spectroscopies, complemented by quantum chemical calculations performed at the DFT(B3LYP)/6-31++G(d,p) level of theory for the isolated molecules. In the neat crystalline solid (space group P1?, a = 6.9763 ?, b = 8.3097 ?, c = 10.0737 ?, α = 96.517°, β = 107.543°, γ = 99.989°; Z = 2), 1-methyltetrazole-saccharinate units assume the most stable configuration for the isolated molecule, (1H)-1-methytetrazole iminosaccharin tautomeric form (1MTIS), with the NC spacer linking the two heterocycles. On the other hand, neat crystalline 2-methyl derivative units (space group P1?, a = 7.8010 ?, b = 8.6724 ?, c = 9.4984 ?, α = 114.083°, β = 107.823°, γ = 93.080°; Z = 2) exist in the (2H)-2-methytetrazole aminosaccharin tautomeric form (2MTAS), with the two heterocycles connected by an NH spacer. In both crystals, the structure consists of a packing of dimeric units, the dimers formed via hydrogen bonding involving either the NH group of the saccharyl system (1MTIS) or the spacer amine group (2MTAS). In the former, the hydrogen bond is bifurcated and the NH group acts as a donor both towards a neighbor molecule and an N atom of the tetrazole ring, forming an intramolecular hydrogen bond. The observed difference in the crystallographic basic units of the two compounds reveals the prevalence of the H-bond networks in determining the structural preferences of the tetrazole-saccharinates in the solid state. Such structural flexibility appears also to be of potential interest in the design of new ligands based on the tetrazole-saccharinate framework. The relative strengths of the H-bonds in the crystals of the two compounds were evaluated through inspection of their vibrational spectra and empirical correlations between spectroscopic data and the H-bond enthalpies and distances.
