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PubMed1988

Treatment of experimental lens-induced uveitis by dimethyl thiourea.

Dimethyl thiourea is a highly specific hydroxyl radical scavenger. The antiinflammatory potential of this hydroxyl radical scavenger was studied in Lewis rats sensitized with soluble lens protein. Intraperitoneal injection of dimethyl thiourea into the experimental animals at the onset of the disease resulted in marked reduction of intraocular inflammation, hemorrhage and edema, and eliminated the retinal and choroidal necrotizing vasculitis that was characteristic in untreated animals. These findings indicate that dimethyl thiourea may act as a potent antiphlogistic agent in the treatment of experimental lens-induced uveitis.

Animals↗
PubMed2006

Novel broad-spectrum thiourea non-nucleoside inhibitors for the prevention of mucosal HIV transmission.

Non-nucleoside inhibitors of HIV-1 reverse transcriptase (NNRTI) are an integral part of combination therapy comprising three classes of antiretroviral drugs for the management of HIV/AIDS. NNRTIs are chemically diverse compounds that bind to a common allosteric site of HIV-1 RT and noncompetitively inhibit DNA polymerization. Resistance to NNRTIs arises rapidly upon drug treatment and results from mutation of the amino acids lining the HIV-1 RT binding pocket. Nevertheless, rationally designed NNRTIs deduced from changes in binding pocket size, shape, and residue character that result from clinically observed NNRTI resistance mutations exhibit broad-spectrum anti-HIV-1 activity. Notably, membrane permeable tight binding NNRTIs have utility as topical microbicides since they are capable of blocking cell-free and cell-associated mucosal HIV-1 infection without metabolic activation. This review summarizes the discovery of highly potent tight binding phenethyl-thiazolyl-thiourea (PETT) derivatives targeting the NNI binding pocket of HIV-1 RT. These NNRTIs were rationally designed by molecular docking using a composite binding pocket constructed by superimposing the crystal structure coordinate data of several NNI/RT ligand-binding site complexes. Molecular modeling and score functions such as molecular surface area, the buried surface, and binding affinity values were used to analyze how drug-resistant mutations would change the RT binding pocket shape, volume, and chemical make-up of these NNRTIs, and how these changes could affect drug binding. Several ligand derivatization sites were identified for docked compounds that fit the binding pocket. The best fit was determined by calculating an inhibition constant (Ludi Ki) of the docked compound for the composite binding pocket. Compounds with a Ludi Ki of <1 microM were identified as the most promising tight binding NNRTIs. This review highlights novel lipophilic thiourea NNRTIs that display high binding affinity and selective indices with robust anti-HIV-1 activity against the wild type as well as drug-resistant isolates carrying multiple RT gene mutations. The increasing prevalence of drug-escape mutants among recent HIV seroconverters makes the discovery of these broad-spectrum thiourea NNRTIs useful as a component of topical microbicide for the prevention of mucosal HIV transmission.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Thioureas and isothiouronium salts of the aglycone of teicoplanin. I. Synthesis and biological activity.

A series of thiourea and isothiouronium salt derivatives of the aglycone of teicoplanin was prepared by reaction of the terminal amino group with isothiocyanates, followed by S-alkylation of the thiourea compounds. Unexpectedly, the two classes of derivatives show a similar in vitro antibacterial activity against Gram-positive bacteria. Thiourea compounds, due to the lack of a positively charged N-terminus group, have a 10-fold lower binding constant to Ac-D-Ala-D-Ala, a bacterial cell-wall model, than the parent antibiotic and isothiouronium salt derivatives.

Anti-Bacterial Agents↗
PubMed1975

Further aspects of the radioprotective mechanism of thiourea.

Thiourea in three different concentrations ranging from 10-4-M to 10-2-M was employed in pre- and post-treatments to test whether it decreases the chromosomal fragment frequency induced by 1000 R of X-rays in the growing root tips of Hordeum vulgare. In pre-treatment experiments thiourea in 10-2-M concentration yielded the maximal protection of 28.9 percent against radiation- induced chromosomal fragments. In post-treatment approximately a similar rate of protection is secured. It is discussed that the test-chemical protected the chromosomes against X-rays by two different mechanisms. The recovery process by restitution of the broken chromosomal fragments and the protection against initial radiation damage were the possible protective mechanisms displayed by thiourea in this plant material.

Adenosine Triphosphate↗
PubMed1975

Effect of 2-thiourea administered to pregnant rats on the thyroid and the protein bound iodine content of the offspring.

A 0.2% solution of 2-thiourea administered during the third or the second and third weeks of pregnancy increased the weight of the thyroid of 20-day old fetuses and newborn rats, and decreased the protein bound iodine content in their thyroid and serum. Similar changes were observed in those weanling rats whose mother had been given a 0.2% solution of thiourea during the period of lactation. Both the intrauterine changes and those occurring during lactation proved reversible. The findings point to the possibility of congenital or infantile thyroid injury caused by thiourea derivatives taken up from the environment.

Animals↗
PubMed2003

[Determination of gold in thiourea and sulfuric acid solution by AAS].

The concentrations of gold in thiourea and sulfuric acid solutions using gold standard solutions in diluent royal water were determined by AAS. The linear range was 0.2-12 x 10(-6), and RSD < 5%. This method simplifies the analysis of gold in thiourea and sulfuric acid solution. Thiourea declines the absorbency of gold while sulfuric acid plays a contrary role. The determined value were satisfactor after being modified by the blank curve.

Gold↗
PubMed1979

14C-Thiourea binding in the rat lung.

Results of the present study demonstrate that in vitro covalent binding of radioactivity from the edematogenic agent [14C] thiourea to rat lung protein can occur under aerobic and anaerobic conditions. Binding of thiourea to lung protein is associated with a reduction in glutathione. The binding of [14C] from thiourea to lung protein is temperature dependent.

Aerobiosis↗
PubMed1980

Teratogenic effect of 2'-thiourea in the rat.

The compound 2'-thiourea was studied for teratogenic effect in fetal rats. A 0.2% aqueous solution of 2'-thiourea (Merck) was administered ad libitum to pregnant rats from the first to the 14th day of pregnancy. The pregnancy was counted from the day when sperm was found in the vaginal smear. In the treated rat fetuses hypoplasia of the brain and spinal cord, internal hydrocephalus, hypoplasia of the spinal ganglia, kypholordosis, micromelia, micrognathia, cleft palate, retarded tooth development, exophthalmus, coloboma, and cataract were observed. In addition, generalized haemorrhages were found all over the body. The changes were similar to those produced by ethylene thiourea treatment in rat fetuses.

Animals↗
PubMed1977

Quantitative determination of thiourea in citrus fruits.

A quantitative method for thiourea determination in orange peels is proposed, with direct reflectance spectrometric measurements on chromatoplates. Thiourea is separated on a silica gel plate with methanol-chloroform (10 + 90), and the spots are characterized with 2,6-dichloroquinone chloroimide; this colorimetric reaction is unstable, so thiourea is quantitated on the chromatogram by direct ultraviolet reflectance spectrometric measurements at 240 nm. Comparison between this method and the AOAC colorimetric method shows interferences and higher results in the colorimetric assay. By slightly modifying the extraction technique, such as purifying the extract on an alumina column, it is possible to decrease these interferences and to avoid erroneous results with the AOAC colorimetric method. For both methods, colorimetry in solution and reflectometry on chromatoplates, applied after the proposed extraction technique, the sensitivity is about 1 ppm and the reliabilities are similar.

Citrus↗
PubMed2004

N-benzoyl-N'-alkylthioureas and their complexes with Ni(II), Co(III) and Pt(II) - crystal structure of 3-benzoyl-1-butyl-1-methyl-thiourea: activity against fungi and yeast.

The thiourea derivatives of N-butylmethylamine (3-benzoyl-1-butyl-1-methyl-thiourea) (1), N-ethylisopropylamine (3-benzoyl-1-ethyl-1-isopropyl-thiourea) (2) and the corresponding complexes of 1 and 2 with Ni(II), Co(III) and Pt(II) have been synthesized. The compounds obtained were characterized by elemental analysis, spectroscopic methods (FT-IR, UV-Vis and NMR) and mass spectrometry. Compound 1, crystallized in the triclinic space group. The antifungal activities of compounds 1 and 2 and their corresponding complexes against the fungus Penicillium digitatum and against the yeast Saccharomyces cerevisiae were investigated. In general, fungal growth inhibition was higher with compound 1 and its complexes than with compound 2, except for the Co(III) complex of 2.

Journal Article↗
PubMed2005

Enantio- and diastereoselective Michael reaction of 1,3-dicarbonyl compounds to nitroolefins catalyzed by a bifunctional thiourea.

We synthesized a new class of bifunctional catalysts bearing a thiourea moiety and an amino group on a chiral scaffold. Among them, thiourea 1e bearing 3,5-bis(trifluoromethyl)benzene and dimethylamino groups was revealed to be highly efficient for the asymmetric Michael reaction of 1,3-dicarbonyl compounds to nitroolefins. Furthermore, we have developed a new synthetic route for (R)-(-)-baclofen and a chiral quaternary carbon center with high enantioselectivity by Michael reaction. In these reactions, we assumed that a thiourea moiety and an amino group of the catalyst activates a nitroolefin and a 1,3-dicarbonyl compound, respectively, to afford the Michael adduct with high enantio- and diastereoselectivity.

Journal Article↗
PubMed2006

Thiourea-catalyzed asymmetric michael addition of activated methylene compounds to alpha,beta-unsaturated imides: dual activation of imide by intra- and intermolecular hydrogen bonding.

A thiourea-catalyzed asymmetric Michael addition of activated methylene compounds to alpha,beta-unsaturated imides derived from 2-pyrrolidinone and 2-methoxybenzamide has been developed. In the case of 2-pyrrolidinone derivatives, the reaction with malononitrile proceeded in toluene with high enantioselectivity, providing the Michael adducts in good yields. However, the nucleophiles that could be used for this reaction were limited to malononitrile due to poor reactivity of the substrate. Further examination revealed that N-alkenoyl-2-methoxybenzamide was the best substrate among the corresponding benzamide derivatives bearing different substituents on the aromatic ring. Indeed, several activated methylene compounds such as malononitrile, methyl alpha-cyanoacetate, and nitromethane could be employed as a nucleophile to give the Michael adducts in good to excellent yields with up to 93% ee. The results of spectroscopic experiments clarified that this enhanced reactivity can be attributed to the intramolecular hydrogen-bonding interaction between the N-H of the imide and the methoxy group of the benzamide moiety. Thus, the key to the success of the catalytic enantioselective Michael addition is dual activation of the substrate by both intramolecular hydrogen bonding in the imide and intermolecular hydrogen bonding with thiourea 1a, as well as the activation of a nucleophile by the tertiary amine of the bifunctional thiourea.

Journal Article↗
PubMed2003

From thiourea to bicyclic structures: an original route to imidazo[2,1-b]thiazoles, 5H-thiazolo[3,2-a]pyrimidines, 7H-imidazo[2,1-b][1,3]thiazines, and 2H,6H-pyrimido[2,1-b][1,3]thiazines.

We report an example of an efficient regioselective synthesis of biheterocyclic compounds using thiourea as starting material. In fact, N,N'-bis(dimethylaminomethylene)thiourea (1), easily prepared by double condensation of N,N-dimethylformamide dimethyl acetal with thiourea, can be reacted with haloketones or acrylic dienophiles to give thiazolic (2) and thiazinic (3) diazadienes, respectively, themselves undergoing cyclization reactions to yield imidazo[2,1-b]thiazoles, 5H-thiazolo[3,2-a]pyrimidines, 7H-imidazo[2,1-b][1,3]thiazines, and 2H,6H-pyrimido[2,1-b][1,3]thiazines without any regioisomeric ambiguity. This straightforward route represents an original and unambiguously regioselective pathway to these valuable heterocycles.

Journal Article↗
PubMed2004

A rotational study of laser ablated thiourea.

A laser ablation device in combination with a molecular beam Fourier-transform microwave spectrometer has allowed the observation of the rotational spectrum of solid thiourea for the first time. The sensitivity reached in the experiment allowed the observation of the isotopomers (34)S, (13)C, and (15)N in their natural abundance. The spectrum of D(4)-thiourea was also analyzed from an enriched sample. The complicated hyperfine structure arising from the presence of two (14)N quadrupolar nuclei has been fully resolved and analyzed. The substitution r(s) structure has been derived from the experimental moments of inertia. Thiourea in gas phase presents a planar heavy atom skeleton. Experimental inertial defect values and high-level ab initio calculations reveal that the amino groups hydrogen atoms lie out-of-plane with a C(2) symmetry configuration and are involved in large amplitude inversion motions.

Journal Article↗
PubMed1999

[Surface enhanced Raman scattering of thiourea in acidic solution].

Surface enhanced Raman scattering of thiourea adsorbed on the plated silver surface in an acidic solution has been studied. The results show that the thiourea molecules are inclined to adsorbed on the silver surface via sulphur. When the concentration of HCl in the solution is increased, the plane of the thiourea molecule deviates more from the normal line of the silver surface. The experimental results also suggest that the rather strong chemical enhanced mechanism would exist in this system.

English Abstract↗
PubMed2001

Protective effect of thiourea, a hydroxyl-radical scavenger, on curcumin-induced chromosomal aberrations in an in vitro mammalian cell system.

Natural dietary antioxidants are extensively studied for their ability to protect cells from damage to DNA, protein, and lipids induced by antitumor agents or radiation that leads to the generation of free radical in normal cells in vivo and in vitro. Curcumin is a natural antioxidant known to possess therapeutic properties and has been reported to scavenge free radicals and to inhibit clastogenesis in mammalian cells. However, curcumin has been reported to induce a significant increase in the frequency of chromosomal aberrations in Chinese hamster ovary (CHO) cells. To investigate whether the clastogenic activity of curcumin in CHO cells in culture can be ascribed to a pro-oxidant behavior, mediated by free radical generation, experiments were carried out with the combination of curcumin (15 microg/ml) and thiourea (10, 20, or 40 microg/ml), a potent hydroxyl radical scavenger. The results showed that the clastogenic action of curcumin was statistically decreased in a dose-dependent manner in the presence of thiourea. These data have shown that curcumin-induced chromosomal damage in CHO cells can be mediated by hydroxyl radical generation in the present experimental conditions. Teratogenesis Carcinog. Mutagen. 21:175-180, 2001.

Animals↗
PubMed1998

Use of thiourea to increase the solubility of membrane proteins in two-dimensional electrophoresis.

The separation of membrane proteins by high-resolution two-dimensional electrophoresis was carried out. At high loads, these proteins are prone to precipitation, resulting in poor resolution. It is shown here that the use of thiourea, previously described for focusing in immobilized pH gradients, can be extended to conventional isoelectric focusing. As thiourea inhibits acrylamide polymerization, a modified photopolymerization system must be used. These modifications result in higher solubility of proteins during IEF, thereby increasing the resolution and capacity of the two-dimensional gels.

Cell Line↗
PubMed1983

Steroidal thiourea and thiazoline derivatives: synthesis and in vitro effects on bovine pancreatic ribonuclease activity.

Two novel series of steroidal derivatives containing various thiourea and substituted thiazoline moieties attached to the 2- or 4-position of estrone were synthesized and examined for in vitro effect on bovine pancreatic ribonuclease activity. All compounds studied exhibited a catabolic activity. The steroidal thiazoline derivatives were more potent activators of ribonuclease than the steroidal thioureas.

Animals↗