Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “THIOUREA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources
PubMed1985

Effect of thiourea on the testicular steroidogenesis and secondary sexual characters of a tropical freshwater fish, Mystus (M) vittatus (Bloch).

300 ppm of thiourea solution was found to produce significant decline in the interstitial cells of the testes of Mystus (M) vittatus. The regressive changes have been observed both in the number and the size (diameter) of these cells. The thiourea though could not bring about appreciable changes up to the second week, but during third and fourth week marked cellular regression in the interstitial cells has been recorded. Such cellular changes appear to influence the development of the genital papilla and caudal thickening (the secondary sexual characters - SSC) in the male specimens. Changes in the interstitial cells indicative of gonadal steroidogenesis correlated with the SSC is for the first time reported in a tropical fish. Interesting findings have been described and discussed.

Animals↗
PubMed1982

[Synthesis and h2-antihistaminic activity of n,n'-bisimidazole-substituted thioureas, cyanoguanidines and 2-nitro-1,1-ethenediamines 10. C: H2-antihistaminics].

In studies on structure-activity relationships of histamine H2-receptor antagonists, N,N'-bis(2-[(4-imidazolyl)-methylthio]-ethyl)-substituted thioureas, cyanoguinidines, and 2-nitro-1,1-ethenediamines with different C-5 methylation of the imidazole rings were prepared and tested for their H2-antihistaminic activity on the isolated guinea-pig atrium and the stimulated gastric acid secretion of the anaesthetized rat. When tested on isolated guinea-pig atrium, substances with both C-5 positions methylated (5b, 7b, 9b) proved to be up to seven times more active than metiamide, whereas inhibition of gastric acid secretion turned out to be less marked. While equally methylated thioureas and cyanoguanidines showed same potency, the 2-nitro-1,1-ethenediamines clearly possessed lower activity.

Animals↗
PubMed1995

Denaturation of pteroylpoly-gamma-glutamyl hydrolase from chicken liver by urea, thiourea and guanidine hydrochloride: altered catalytic properties of the enzyme activated by urea.

The effects of varying concentrations of urea, thiourea and guanidine hydrochloride on the enzyme activity and the isoenzymic polypeptide association of pteroylpoly-gamma-glutamyl hydrolase (EC 3.4.22.12) from chicken liver were studied. Incubation of the enzyme at 4 degrees C with low concentrations of the buffered (100 mM sodium acetate containing 1% ascorbate, pH 4.1) solutions of urea (0.55 M) and guanidine hydrochloride (0.05 M) resulted in stimulation (5- and 2-fold respectively) of the activity of the enzyme whereas at higher concentrations of the denaturants (6 M urea, 1 M thiourea or 2 M guanidine hydrochloride) the enzyme was completely inactivated. However, there was no enzyme activation in response to thiorea treatment. Under specific denaturing conditions the association of two isoenzymic polypeptides was studied. The 0.55 M urea- and 0.05 M guanidine hydrochloride-activated enzyme displayed its disaggregated nonidentical polypeptides I and II (M(r) = 41,000 and 17,300 respectively) on Sephadex G-100 gel filtration, SDS-PAGE and sedimentation analyses. The 8 M urea- and 3 M guanidine hydrochloride-inactivated enzyme on the other hand exhibited a single protein aggregate species of an M(r), 57,000 like the native enzyme. Both unmodified native enzyme and the pCMB-modified PtepolyGlu hydrolase responded similarly to these denaturants. The two constituent active polypeptides polyp-I and polyp-II of the heterodimeric gamma-glutamyl glutamyl hydrolase are dissociated in the presence of 0.55 M urea as evident from the PAGE analyses. Some catalytic properties of the activated enzyme were studied and compared with those of the native enzyme. The urea-activated enzyme displayed a shift in the second pH optimum of the double pH-activity profile (optima at pH 4.1 and pH 5.2) from pH 5.2 to pH 6.0. The activated enzyme has a Km value of 0.59 x 10(-6) M (Vmax, 0.10) for 5-CH3-H4PteGlu4 while the native enzyme has the Km of 0.83 x 10(-6) M (Vmax, 0.03) for this substrate. When the reaction mixtures were incubated with the urea-activated gamma-glutamyl hydrolase, a maximum stimulatory effect on the enzyme activity was observed with the bivalent metal ion Ca2+ whereas the most potent inhibitory effect was observed with the trivalent anion citrate.

Animals↗
PubMed2000

The kinetics of substitution reactions of mixed platinum(II)-bis(nucleoside) complexes in aqueous solution in the presence of thiourea; X-ray crystal structure determination of cis-

In aqueous solution, bis(nucleoside) complexes formed by the reaction of cis-[Pt(NH3)2(H2O)2]2+ with an excess of either adenosine (ado) or a mixture of adenosine and guanosine (guo) undergo a slow N7--> N1 linkage isomerisation in the adenine moiety. The isomerisation probably involves the breaking and reformation of Pt-nucleoside bonds, thus favouring the more stable N1 binding mode of the adenine base. Dynamic processes due to the presence of adenosine in the platinum coordination sphere are slow on the NMR time scale. The N7 binding mode of PtII in cis-[Pt(NH3)2(ado-N7)2](ClO4)2. 3.5H2O was confirmed by X-ray crystal structure analysis. In both of the crystallographically independent cations, the PtII coordination sphere is almost ideally square planar, with typical Pt-N bond lengths and angles. The most significant difference between the two cations lies in the sugar conformation of the coordinated nucleosides. In one cation, both have an anti (-ap) conformation, whilst in the other cation one has an anti (-ap) conformation and the other a syn (+sc) conformation stabilised by a relatively strong H-bond. Substitution of the nucleoside(s) by thiourea follows an associative mechanism with only a negligible contribution by the solvent path. For symmetric complexes, the order of lability of different binding modes is ado-N1 <guo-N7 < ado-N7 for substitution of the first nucleoside, whereas for the second nucleoside it is guo-N7 < ado-N1 < ado-N7. For asymmetric complexes, the concomitant cleavage of different PtII-nucleoside bonds can be explained by two parallel reaction pathways. The change in the PtII coordination sphere affects the lability of the coordinating nucleosides in a different manner. The ado-N1 binding mode renders all binding modes less labile, whereas the ado-N7 mode has the opposite effect, and the guo-N7 mode increases the lability of the ado-N1 mode but decreases that of the ado-N7 mode. The mixed-ligand complex with (ado-N7)(guo-N7) mode is far more susceptible to attack by thiourea than the symmetric (guo-N7)2 species. These two species can be considered as models for the two most abundant Cisplatin-DNA adducts.

Journal Article↗
PubMed2005

Synthesis and in vitro antitubercular activity of some 1-[(4-sub)phenyl]-3-(4-{1-[(pyridine-4-carbonyl)hydrazono]ethyl}phenyl)thiourea.

Various isonicotinyl hydrazones were prepared by reacting isonicotinyl hydrazide [INH] with 1-(4-acetylphenyl)-3-[(4-sub)phenyl]thiourea and were tested for their antimycobacterial activity in vitro against Mycobacterium tuberculosis H37Rv and INH-resistant M. tuberculosis using the BACTEC 460 radiometric system. Among the synthesized compounds, 1-(4-fluorophenyl)-3-(4-{1-[(pyridine-4-carbonyl)-hydrazono]ethyl}phenyl)thiourea (4d) was found to be the most potent compound with a minimum inhibitory concentration of 0.49 microM against M. tuberculosis H37Rv and INH-resistant M. tuberculosis. When compared to INH, 4d was found to be 3 and 185 times more active against M. tuberculosis H37Rv and INH-resistant M. tuberculosis, respectively, with a selectivity index of >300.

Antitubercular Agents↗
PubMedDate not supplied

Solid phase synthesis and application of trisubstituted thioureas.

Resin-bound amines 1a-e condense with isothiocyanates to give thiourea resins 2a-i. Resins 2a-g subsequently react with iodomethane followed by cleavage affording S-methyl isothioureas 4a-g, and resins 2a-b,h-i react with acyl chlorides to afford N-acylated thioureas 6a-d. N-Acylthioureas 8a-f (R(2) = H) were prepared directly from resin-bound amines 1a-d with acyl isothiocyanates. N-Acylthioureas 8a-d,f(R(2) = H) were used for the preparation of S-methyl-N-acylisothioureas 10a-e. Alkylation was performed using methyl iodide. Resin-bound S-methyl-N-acylisothioureas 10a,b,d are converted by an action of hydrazines into 3-amino-1,2,4-triazoles 13a-d. Condensation of resins 8a-e (R(2) = H) with 2-bromoacetophenones in the presence of TEA affords thiazoles 15 a-e. All transformations proceeded in high yields and gave products of good purities.

Journal Article↗
PubMed2003

Synthesis of 2,4-disubstituted thiazoles from (Z)-(2-acetoxyvinyl)phenyl-lambda3-iodanes: nucleophilic substitution of alpha-lambda3-iodanyl ketones with thioureas and thioamides.

In the presence of triethylamine, (Z)-(2-acetoxy-1-alkenyl)phenyl-lambda(3)-iodanes react with thioureas or thioamides in MeOH to give 2,4-disubstituted thiazoles directly in good yields. The reaction probably involves generation of highly reactive alpha-lambda(3)-iodanyl ketones through ester exchange of the beta-acetoxy group with liberation of methyl acetate, followed by nucleophilic substitutions with thioureas or thioamides.

Journal Article↗
PubMed2000

Synthesis and anion-selective complexation of cyclophane-based cyclic thioureas

Cyclic thiourea derivatives having three different types of cyclophane structure, ortho-meta, meta-meta, and meta-para, and a lariat-type thiourea, were synthesized, and their anion-binding ability was examined. The association constants for the complexation between the receptors and several anions in DMSO-d(6) were measured by the titration method using (1)H NMR spectroscopy. All receptors, except for the meta-para cyclophane, exhibit selective binding to the dihydrogenphosphate anion, which is stronger than that of the acyclic reference compound. The lariat-type receptor binds anions even more strongly than the cyclic receptors which do not possess the third binding site.

Journal Article↗
PubMed2003

"One-pot" two-step synthesis of aryl sulfur compounds by photoinduced reactions of thiourea anion with aryl halides.

[reaction: see text]. The photoinduced reactions of aryl halides with the thiourea anion afford arene thiolate ions in DMSO. These species without isolation, and by a subsequent aliphatic nucleophilic substitution, S(RN)1 reaction, oxidation, or protonation, yield aryl methyl sulfides, diaryl sulfides, diaryl disulfides, and aryl thiols with good yields (50-80%). This is a simple and convenient approach which involves the use of the commercially available and inexpensive thiourea in a "one-pot" two-step process for the synthesis of aromatic sulfur compounds.

Journal Article↗
PubMed2005

First metallamacrocyclic complexes of Pt(iv) with 3,3,3',3'-tetraalkyl-1,1'-phenylenedicarbonylbis(thioureas): synthesis by direct or electrolytic oxidative addition of I(2), Br(2) and Cl(2).

Elemental I(2) and Br(2) cleanly react with the 3:3 Pt(ii) metallamacrocycle of 3,3,3',3'-tetra(n-butyl)-1,1'-terephthaloylbis(thiourea)(cis-[Pt(II)(3)(L(p)(1)-S,O)(3)]3), in chloroform at room temperature, to yield oxidative addition products; (195)Pt NMR studies reveal that a stepwise oxidative addition readily occurs to each of the Pt(ii) centres in the metallamacrocycle to yield the mixed valence species cis-[Pt(II)(2)Pt(IV)I(2)(L(p)(1)-S,O)(3)] and cis-[Pt(II)Pt(IV)(2)I(4)(L(p)(1)-S,O)(3)], and the fully oxidised cis-[Pt(IV)(3)I(6)(L(p)(1)-S,O)(3)] in solution, depending on the mole ratio I(2):3. Similar results are obtained on treatment of solutions of 3 with elemental Br(2). Treatment of the corresponding 2:2 Pt(ii) complex of 3,3,3',3'-tetraethyl-1,1'-isophthaloylbis(thiourea)(cis-[Pt(II)(2)(L(m)(1)-S,O)(2)]4) with iodine, results in facile oxidative addition to yield cis-[Pt(IV)(2)(L(m)(1)-S,O)(2)I(4)], with a trans-Pt(iv)-iodo arrangement. Molecules in the crystal structure of 5 have their trans-Pt(iv)-iodo axes essentially aligned, with very close intermolecular iodide contacts (3.775(1)A), resulting in chains of weakly bound metallamacrocycles in the solid. An alternative electrolytic synthesis method, using a simple two-compartment glass cell containing 4 and a chosen halide salt in dichloromethane, led to the formation of cis-[Pt(IV)(2)(L(m)(1)-S,O)(2)Br(4)] 6 and cis-[Pt(IV)(2)(L(m)(1)-S,O)(2)Cl(4)] 7, completing characterization of a series of first-reported trans-Pt(iv)-X (X=I, Br, Cl) metallamacrocyclic complexes.

Journal Article↗
PubMed2003

Unique mechanism of action of the thiourea drug isoxyl on Mycobacterium tuberculosis.

The thiourea isoxyl (thiocarlide; 4,4'-diisoamyloxydiphenylthiourea) is known to be an effective anti-tuberculosis drug, active against a range of multidrug-resistant strains of Mycobacterium tuberculosis and has been used clinically. Little was known of its mode of action. We now demonstrate that isoxyl results in a dose-dependent decrease in the synthesis of oleic and, consequently, tuberculostearic acid in M. tuberculosis with complete inhibition at 3 microg/ml. Synthesis of mycolic acid was also affected. The anti-bacterial effect of isoxyl was partially reversed by supplementing growth medium with oleic acid. The specificity of this inhibition pointed to a Delta9-stearoyl desaturase as the drug target. Development of a cell-free assay for Delta9-desaturase activity allowed direct demonstration of the inhibition of oleic acid synthesis by isoxyl. Interestingly, sterculic acid, a known inhibitor of Delta9-desaturases, emulated the effect of isoxyl on oleic acid synthesis but did not affect mycolic acid synthesis, demonstrating the lack of a relationship between the two effects of the drug. The three putative fatty acid desaturases in the M. tuberculosis genome, desA1, desA2, and desA3, were cloned and expressed in Mycobacterium bovis BCG. Cell-free assays and whole cell labeling demonstrated increased Delta9-desaturase activity and oleic acid synthesis only in the desA3-overexpressing strain and an increase in the minimal inhibitory concentration for isoxyl, indicating that DesA3 is the target of the drug. These results validate membrane-bound Delta9-desaturase, DesA3, as a new therapeutic target, and the thioureas as anti-tuberculosis drugs worthy of further development.

Amino Acid Sequence↗
PubMed1980

A rapid chromatographic procedure for the isolation and quantitation of 1-(2-Aminoethyl)-3-(2,6-dichlorophenyl) thiourea from dietary admix followed by HPLC.

An analytical procedure is described for the determination of 1-(2-aminoethyl)-3-(2,6-dichlorophenyl) thiourea in dietary admix. Because of the complex nature of the carrier matrix, sample cleanup was required prior to HPLC separation. Sample cleanup was achieved using a cation-exchange microcolumn which yield highly reproducible results. HPLC separation was accomplished using a 10 mu C18 column, monitoring the column effluent in the ultraviolet region at 254 nm. After sample cleanup, 1-(2-aminoethyl)-3-(2,6-dichlorophenyl) thiourea could be detected at levels as low as 3 ppm in dietary admix.

Animal Feed↗
PubMed2002

catena-Poly[[bis(thiocyanato-kappa N)cadmium(II)]-di-mu-thiourea-kappa(4)S:S].

The Cd(II) ion in the title complex, [Cd(SCN)(2)[SC(NH(2))(2)](2)](infinity), is situated at a centre of symmetry, and is bound to two N atoms belonging to thiocyanate groups and to four S atoms of bridging thiourea ligands. The structure consists of infinite chains of slightly distorted edge-shared Cd-centred octahedra. The bridging S atoms of two thiourea ligands comprise the common edge. Some thermal properties are described.

Journal Article↗
PubMed1991

Synthesis and biological evaluation of N-salicyloyl-N-benzyl thiourea and 2,2-dimethyl-4-oxo-6-methoxy benzo-1,3-dioxin.

The synthesis of N-salicyloyl-N-benzyl-thiourea and 2,2-dimethyl-4-oxo-6-methoxy-benzo-1,3-dioxin are described. They were studied for their antiviral, antiproliferative and antimicrobial activities in vitro. N-salicyloyl-N-benzyl-thiourea exhibited significant activity against Gram-positive bacteria and against influenza viruses types A/Philippine/H3N2, A/Chilli/H1N1 and B/Paraha, as well as against K562 cell proliferation. By contrast, no such activity was demonstrated by 2,2-dimethyl-4-oxo-6-methoxy-benzo-1,3-dioxin.

Anti-Bacterial Agents↗
PubMed1983

[Antiviral agents. 22. N-aliphatic, N-alicyclic and N-polycyclic substituted N'-(2-adamantyl)ureas and -thioureas].

With reference to the role that (2-adamantyl), urea, and thiourea moieties play in antiviral drugs, these structural elements have been included in the present investigations aimed at the development of the N-substituted N'-(2-adamantyl)-thioureas 3a-d through the reaction of 2-aminoadamantane (1) with the isothiocyanates 2a-d. In an analogous manner, the interaction of 1 with the isocyanates 2e-f has led to the N-substituted N'-(2-adamantyl)ureas 3e-f. Within structure type 3 there occur representatives exhibiting antiviral, antimycotic, and herbicidal activity.

Adamantane↗
PubMedDate not supplied

Development of novel high-sensitivity chemiluminescence assay for luminol using thiourea derivatives.

We have screened about 100 thiourea derivatives in order to develop a sensitive chemiluminescence detection for luminol derivatives. Among these derivatives, we found a new compound, 2-(3-methylthioureido) thiazole, that could be used to measure luminol in the presence of hydrogen peroxide (H(2)O(2)). The detection limits of luminol and N-(4-aminobutyl)-N-ethylisoluminol (ABEI) were 10 fmol and 100 fmol, respectively. The mechanism of proposed chemiluminescence reaction was studied by electron spin resonance (ESR) with and without superoxide dismutase (SOD) and the addition of ethanol. The results showed that 2-(3-methylthioureido) thiazole has the ability to generate hydroxyl radical from H(2)O(2), and produces intense chemiluminescence in the presence of luminol. The proposed novel chemiluminescence reaction for luminol and luminol derivatives was applied to a high performance liquid chromatography (HPLC) assay for amino compounds.

Amino Acids↗
PubMed2006

The interaction between N-n-undecyl-N'-(sodium p-aminobenzenesulfonate) thiourea and serum albumin studied using various spectroscopies and the molecular modeling method.

The preparation and characteristics of N-n-undecyl-N'-(sodium-p-aminobenzenesulfonate) thiourea (UPT), a new water-soluble reagent with a saturated fatty hydrocarbon group, were described. The interactions of UPT with bovine serum albumin (BSA) and human serum albumin (HSA) were studied using fluorescence spectroscopy in combination with ultraviolet (UV) absorption spectroscopy, circular dichroism (CD) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and the molecular modeling method. UPT exhibited a strong ability to quench the intrinsic fluorescence of both BSA and HSA through a static quenching procedure. The binding constants of UPT and BSA or HSA were determined at different temperatures based on the relevant fluorescence data. The binding sites were obtained and the acting force was suggested to be mainly hydrophobic interaction, which was consistent with the result of the molecular modeling study, and there were also a number of hydrogen bonds between UPT and HSA. The results of determination of the proteins in bovine serum or human serum by this method were very close to those obtained by using Coomassie Brilliant Blue G-250 colorimetry. A practical method was proposed for the determination of UPT in bovine serum or human serum samples with satisfactory results.

Animals↗