98-10-2Relevant articles and documents
MECHANISTIC INVESTIGATIONS WITH POSITIVE HALOGENS: KINETICS OF OXIDATION OF THIOSEMICARBAZIDE BY CHLORAMINE-B, BROMAMINE-B AND DICHLORAMINE-B IN ACID MEDIUM
Gowda, B. Thimme,Bhat, J. Ishwara
, p. 2119 - 2128 (1987)
Kinetics of oxidation of thiosemicarbazide (TSC) by chloramine-B (CAB), and bromamine-B (BAB) in aqueous perchloric acid medium and by dichloramine-B (DCB) in 1:1 (v/v) water-methanol medium has been studied.The rate followed first order kinetics in and inverse fractional order in with all the oxidants.But it was fractional order in with CAB and independent of with BAB and DCB.Addition of benzenesulphonamide, the reduced product of the oxidants had no effect on the rate with CAB and BAB but it slightly increased the rate with DCB.Therate decreased with increase in ionis strength of the medium in all cases.Decrease of dielectric constant of the reaction medium by adding methanol had no effect on the rate with CAB and BAB but increased the rate with DCB.The mechanisms proposed and the derived rate laws are in conformity eith the observed results.The coefficients of the rate limiting steps have been calculated.Kinetics observed with HOCl and HOBr support the proposed mechanisms.
Synthesis and X-Ray Structure of Bistetraphenylphosphonium Tris(phenylsulphonylimino)sulphite
Roesky, Herbert W.,Schmieder, W.,Sheldrick, William S.
, p. 1013 - 1014 (1981)
An aza-analogue of sulphite, the structure of which was determined by X-ray diffraction, is prepared from sodium amide and a sulphur di-imide in liquid ammonia.
Chloraminometric and bromaminometric oxidation of sulfanilic acid in alkaline medium: A comparative kinetic and mechanistic study
Puttaswamy,Jagadeesh
, p. 48 - 56 (2006)
The kinetics of oxidation of sulfanilic acid (SAA) by chloramine-B (CAB) and bromamine-B (BAB) has been investigated in alkaline medium at 35 ± 0.1°C. The oxidation reaction follows identical kinetics in the case of both the oxidants with first-order dependence on each [oxidant]o and [SAA]o and an inverse first-order dependence on [OH-]. The variation of ionic strength, dielectric constant of the medium, addition of the reaction product (benzene-sulfonamide), and halide ions showed no significant influence on the reaction rate. Proton inventory studies made in H2O-D2O mixtures for CAB and BAB have been utilized to calculate the isotopic fractionation factor. The reaction has been studied at different temperatures, and activation parameters for the composite reaction have been computed from the Arrhenius plots. N-Hydroxylaminobenzene-4-sulfonic acid was identified as the oxidation product of SAA from IR and GC-MS analysis. A mechanism consistent with the kinetic results is proposed in which PhSO 2NHX (X = Cl or Br) interact with the substrate in the rate-limiting step. A suitable rate law is derived. The rate of oxidation of sulfanilic acid is about fourfold faster in BAB compared to CAB. The oxidation of SAA brought about by CAT and BAT was also investigated under identical experimental conditions, and the overall rate of oxidation of SAA increases in the order: BAB > BAT > CAB > CAT This may be attributed to the difference in electrophilicities of Cl+ and Br+ ions and also the van der Waal's radii of chlorine and bromine.
Synthesis, biological evaluation, and docking studies of novel pyrrolo[2,3-b]pyridine derivatives as both ectonucleotide pyrophosphatase/phosphodiesterase inhibitors and antiproliferative agents
Ullah, Saif,El-Gamal, Mohammed I.,El-Gamal, Randa,Pelletier, Julie,Sévigny, Jean,Shehata, Mahmoud K.,Anbar, Hanan S.,Iqbal, Jamshed
, (2021/03/22)
Ecto-nucleotide pyrophosphatases/phosphodiesterases (NPPs) together with nucleoside triphosphate diphosphohydrolases (NTPDases) and alkaline phosphatases (APs) are nucleotidases located at the surface of the cells. NPP1 and NPP3 are important members of NPP family that are known as druggable targets for a number of disorders such as impaired calcification, type 2 diabetes, and cancer. Sulfonylurea derivatives have been reported as antidiabetic and anticancer agents, therefore, we synthesized and investigated series of sulfonylurea derivatives 1a-m possessing pyrrolo[2,3-b]pyridine core as inhibitors of NPP1 and NPP3 isozymes that are over-expressed in cancer and diabetes. The enzymatic evaluation highlighted compound 1a as selective NPP1 inhibitor, however, 1c was observed as the most potent inhibitor of NPP1 with an IC50 value of 0.80 ± 0.04 μM. Compound 1l was found to be the most potent and moderately selective inhibitor of NPP3 (IC50 = 0.55 ± 0.01 μM). Furthermore, in vitro cytotoxicity assays of compounds 1a-m against MCF-7 and HT-29 cancer cell lines exhibited compound 1c (IC50 = 4.70 ± 0.67 μM), and 1h (IC50 = 1.58 ± 0.20 μM) as the most cytotoxic compounds against MCF-7 and HT-29 cancer cell lines, respectively. Both of the investigated compounds showed high degree of selectivity towards cancer cells than normal cells (WI-38). Molecular docking studies of selective and potent enzyme inhibitors revealed promising mode of interactions with important binding sites residues of both isozymes i.e., Thr256, His380, Lys255, Asn277 residues of NPP1 and His329, Thr205, and Leu239 residues of NPP3. In addition, the most potent antiproliferative agent, compound 1h, doesn't produce hypoglycemia as a side effect when injected to mice. This is an additional merit of the promising compound 1h.
Development of succinimide-based inhibitors for the mitochondrial rhomboid protease PARL
Andrews, Charlotte L.,Cardozo, Joaquin M.,Chow, Alyssa S.,Crainic, Jennifer A.,Parsons, William H.,Rutland, Nicholas T.,Sheehan, Brendan K.
supporting information, (2021/08/04)
While the biochemistry of rhomboid proteases has been extensively studied since their discovery two decades ago, efforts to define the physiological roles of these enzymes are ongoing and would benefit from chemical probes that can be used to manipulate the functions of these proteins in their native settings. Here, we describe the use of activity-based protein profiling (ABPP) technology to conduct a targeted screen for small-molecule inhibitors of the mitochondrial rhomboid protease PARL, which plays a critical role in regulating mitophagy and cell death. We synthesized a series of succinimide-containing sulfonyl esters and sulfonamides and discovered that these compounds serve as inhibitors of PARL with the most potent sulfonamides having submicromolar affinity for the enzyme. A counterscreen against the bacterial rhomboid protease GlpG demonstrates that several of these compounds display selectivity for PARL over GlpG by as much as two orders of magnitude. Both the sulfonyl ester and sulfonamide scaffolds exhibit reversible binding and are able to engage PARL in mammalian cells. Collectively, our findings provide encouraging precedent for the development of PARL-selective inhibitors and establish N-[(arylsulfonyl)oxy]succinimides and N-arylsulfonylsuccinimides as new molecular scaffolds for inhibiting members of the rhomboid protease family.