1826-22-8Relevant academic research and scientific papers
N-hydroxy-4-(4-chlorophenyl)thiazole-2(3H)-thione as a photochemical hydroxyl-radical source: Photochemistry and oxidative damage of DNA (strand breaks) and 2′-deoxyguanosine (8-oxodG formation)
Adam, Waldemar,Hartung, Jens,Okamoto, Hideki,Saha-Moeller, Chantu R.,Spehar, Kristina
, p. 619 - 624 (2000)
On irradiation of N-hydroxythiazole-2(3H)-thione 3 at 300 nm, the photoproducts disulfide 4, bisthiazole 5 and thiazole 6 are formed. During this photolysis, hydroxyl radicals are released, which have been detected by spin trapping with 5,5-dimethyl-1-pyrroline N-oxide (DMPO), coupled with electron paramagnetic resonance spectroscopy. In the presence of supercoiled pBR322 DNA, irradiation of thiazolethione 3 induces strand breaks through the photogenerated hydroxyl-radicals, as confirmed by control experiment with the hydroxyl-radical scavenger isopropanol. Singlet oxygen appears not to be involved, as attested by the lack of a D2O isotope effect. During the photoreaction of thiazolethione 3 in the presence of 2′-deoxyguanosine (dG), the latter is photooxidized (ca 10% conversion after 2 h of irradiation) to the 7,8-dihydro-8-oxo-2′-deoxyguanosine as the main oxidation product. The dG conversion levels off after complete consumption of thiazolethione 3 and is suppressed by the addition of the hydroxyl-radical scavenger 2,6-di-tert-butylcresol or DMPO. Since the photoproducts 4-6 are ineffective as sensitizers for the photooxidation of dG and DNA, the hydroxyl radicals released in the photolysis of thiazolethione 3 are the oxidizing species of DNA and dG. These results suggest that the thiazolethione 3 may serve as a novel and effective photochemical hydroxyl-radical source for photobiological studies.
ENZYME INTERACTING AGENTS
-
Paragraph 0144, (2016/05/19)
The present disclosure relates generally, but not exclusively, to compounds and their use as enzyme interacting agents, in particular, agents which interact with one or more enzymes in the sphingolipid biosynthesis pathway. The disclosure further relates
NaBH4-TMEDA and a palladium catalyst as efficient regio- and chemoselective system for the hydrodehalogenation of halogenated heterocycles
Chelucci, Giorgio,Figus, Susanna
, p. 191 - 209 (2014/07/21)
The pair NaBH4-TMEDA as hydride source and a palladium catalyst in THF prove to be an efficient system for the hydrodehalogenation of halogenated heterocycles with one or more heteroatoms. In general, Pd(OAc) 2-PPh3 rapidly hydrodehalogenates reactive halo-heterocycles such as bromo-pyridines, -quinolines, -thiophenes, -indoles, -imidazoles, etc., at room temperature in very good yields, whereas in most cases PdCl2(dppf) reduces less reactive halides such as chloro-pyridines, -quinolines, -pyrimidines and bromo-indoles, -benzofurans, etc. Moreover, PdCl2(tbpf) shows to be even more active removing the 2- and 5-chlorine from both thiophene and thiazole rings. The reaction conditions tolerate various functional groups, allowing highly chemoselective reactions in the presence of halide, ester, alkyne, alkene and nitrile substituents. Moreover, with a proper selection of the catalyst it is also possible to obtain a good control in the regioselective hydrodehalogenation of a variety of polyhalogenated substrates.
Programmed synthesis of arylthiazoles through sequential C-H couplings
Tani, Satoshi,Uehara, Takahiro N.,Yamaguchi, Junichiro,Itami, Kenichiro
, p. 123 - 135 (2014/01/06)
A programmed synthesis of privileged arylthiazoles via sequential C-H couplings catalyzed by palladium or nickel catalysts has been accomplished. This versatile protocol can supply all possible arylthiazole substitution patterns (2-aryl, 4-aryl, 5-aryl, 2
Novel series of 3-amino-N-(4-aryl-1,1-dioxothian-4-yl)butanamides as potent and selective dipeptidyl peptidase IV inhibitors
Nitta, Aiko,Fujii, Hideaki,Sakami, Satoshi,Satoh, Mikiya,Nakaki, Junko,Satoh, Shiho,Kumagai, Hiroki,Kawai, Hideki
, p. 7036 - 7040 (2013/01/15)
A series of novel 3-amino-N-(4-aryl-1,1-dioxothian-4-yl)butanamides were investigated as dipeptidyl peptidase IV (DPP-4) inhibitors. Introduction of a 4-phenylthiazol-2-yl group showed highly potent DPP-4 inhibitory activity. Among various derivatives, (3R)-3-amino-N-(4-(4-phenylthiazol-2-yl)-tetrahydro-2H- thiopyran-4-yl)-4-(2,4,5-trifluorophenyl)butanamide 1,1-dioxide (30) reduced blood glucose excursion in an oral glucose tolerance test by oral administration.
Microwave-assisted generation of alkoxyl radicals and their use in additions, β-fragmentations, and remote functionalizations
Hartung, Jens,Daniel, Kristina,Gottwald, Thomas,Gross, Andreas,Schneiders, Nina
, p. 2313 - 2322 (2008/02/08)
Microwave irradiation (2.45 GHz, 300-500 W) of N-(alkoxy)thiazole-2(3H)- thiones in low-absorbing solvents affords alkoxyl radicals, which were identified by (i) spin adduct formation (EPR-spectroscopy) and (ii) fingerprint-type selectivities in intramolecular additions (stereoselective synthesis of disubstituted tetrahydrofurans), β-fragmentations (formation of carbonyl compounds), and C,H-activation of aliphatic subunits, by δ-selective hydrogen atom transfer. C-Radicals formed from oxygen-centered intermediates were trapped either by Bu3SnH, l-cysteine ethyl ester, the reduced form of glutathione (reductive trapping), or by bromine atom donor BrCCl3 (heteroatom functionalization) The results suggest that microwave activation is superior to UV/Vis-photolysis and conductive heating for alkoxyl radical generation from N-(alkoxy)thiazolethiones. It offers by far the shortest reaction times along with the option to reduce the amount of trapping reagent significantly. The Royal Society of Chemistry 2006.
Photoreactions of N-alkoxy-4-(p-chlorophenyl)thiazole-2(3H)-thiones with L-cysteine derivatives in aqueous solutions
Hartung,Kneuer,Spehar
, p. 799 - 800 (2007/10/03)
Photolysis of substituted N-alkoxythiazolethiones 1 in aqueous solvents furnishes alkoxyl radicals 2 which, upon stereoselective 5-exo-trig cyclization, are trapped by water soluble thiols (L-cysteine, L-cysteine ethyl ester, or the reduced form of glutathione, GSH) to afford disubstituted tetrahydrofurans 3 in synthetically useful yields and with satisfactory to excellent diastereoselectivities.
