5422-44-6Relevant articles and documents
Molecular structure of nitrogen-linked methyltetrazole-saccharinates
Ismael, Amin,Paix?o, José António,Fausto, Rui,Cristiano, Maria Lurdes S.
, p. 128 - 142 (2012)
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.
Electron transfer in a trinuclear oxo-centred mixed-valence iron complex, in solid and solution states
Stadler,Daub,Koehler,Saalfrank,Coropceanu,Schuenemann,Ober,Trautwein,Parker,Poyraz,Inomata,Cannon
, p. 3373 - 3383 (2001)
Complexes [FeIII2MIIOL3] (M = Fe, Co, Ni, Cu; 2, 3, 4, 5) have been synthesised in which L2- is a pentadentate ligand designed to coordinate all three metal atoms in the central cluster and to inhibit dissociation and solvent exchange processes. Crystal structures for 2, 4 and 5 show threefold symmetry, attributed to rotational disorder. Magnetisation data for 2 indicate strong superexchange between basis oxidation states Fe(3+, 3+, 2+). Comparisons of IR spectra across the series of complexes confirm the non-threefold symmetry of the mixed-valence cluster on the vibrational time scale, both in the solid state and in solution. Proton NMR spectra in solution at room temperature do not distinguish the three iron sites, suggesting that pseudo-rotation by thermal electron transfer also operates. Cyclic voltammetry and spectroelectrochemical measurements show that the mixed-valence iron complex 2 can be oxidised reversibly to give the tri-iron(III) complex [Fe3OL3]+ and reduced reversibly and quasireversibly to give respectively [Fe3OL3]- and tri-iron(II) [Fe3OL3]2-, E0 = 85,-635, -1230 mV (versus Fc+/0) in dichloromethane (T = 298 K, 0.1 M [n-Bu4N][PF6]). Moessbauer spectra of 2 indicate significant valence delocalisation even at low temperature (4.2 K) with estimated valences Fe(2.9+, 2.9+, 2.2+) in the solid state. At higher temperatures no lifetime broadening is observed but additional Moessbauer absorptions are consistent with increasing proportions of trimer molecules with greater delocalisation, i.e. Fe(2.75+, 2.75+, 2.5+). In frozen solution (THF) the spectra indicate increasing proportions of molecules fully valence-delocalised on the Moessbauer time scale. The data are accounted for with a model which places the complex at the Robin-Day class III/II borderline. It combines strong superexchange with significant double exchange even at the lowest temperatures, while at higher temperatures in solution complete valence delocalisation occurs through intramolecular electron transfer at rates intermediate between the IR and NMR time scales.
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)
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.
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.
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
