Thiation of Nucleosides. III. Oxidation of 6-Mercaptopurines<sup>1</sup>

Doerr, Iris L.; Wempen, Iris; Clarke, Donald A.; Fox, Jack J.

doi:10.1021/jo01067a093

Cited by 85 publications

(61 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because of the high concentrations required for the maximum effect of these thiols, we hypothesized that the true activators were oxidation products generated during the enzyme assay. Since disulphides of these compounds were easily prepared and purified (Doerr et al, 1961), this was readily confirmed. The optimum concentration of the disulphides of these two thiols was approx.…”

Section: Resultsmentioning

confidence: 75%

See 1 more Smart Citation

Activation of intestinal brush border guanylate cyclase by aromatic disulphide compounds

Eldeib

Parker

White

1991

Biochemical Journal

View full text Add to dashboard Cite

Guanylate cyclase in pig intestinal brush border membranes was stimulated by certain aromatic disulphides. The most effective were 6-thioguanine disulphide [(TGS)2, 6-mercaptopurine disulphide, 6,6'-dithiodinicotinic acid, 5,5'-dithiobis-(2-nitrobenzoic acid) and 5-carboxy-2-thiouracil disulphide. (TGS)2 stimulated activity 15-fold when present at 0.1 mm. The optimum concentration for each disulphide was different, and higher concentrations were inhibitory. There was no activation by alkyl disulphides or by N-ethylmaleimide. Activation by 50 ,tM-(TGS)2 was partially reversed by later addition of 0.1 mM-dithiothreitol, whereas activation by the Escherichia coli heat-stable enterotoxin STa was relatively unaffected. Pretreatment of the membranes with (TGS)2 produced a concentration-dependent inhibition of STastimulated activity, while stimulating basal activity, until the activities were equal at 50 SM. Substitution of Mn2+ for Mg2+ in the reaction elevated basal activity and eliminated by activation (TGS)2. (TGS)2 only inhibited Mn2+-dependent activity (both basal and stimulated). The affinity of 125I-STa for its receptor was slightly increased by (TGS)2. We propose that (TGS)2 undergoes thiol-disulphide exchange with at least three different protein thiols of decreasing reactivity. The first is associated with Mg2+-dependent activation, the second is associated with a tonic inhibition of activity and the third is associated with the catalytic activity, although probably not at the active site.

show abstract

Section: Resultsmentioning

confidence: 75%

“…(TGS)2, 6-mercaptopurine disulphide and 5-carboxy-2-thiouracil disulphide were synthesized from the corresponding thiol compounds by oxidation with 12 (Doerr et al, 1961) and purified by recrystallization. Purified Lubrol PX was obtained from Pierce, and dithiothreitol (DTT) was from Research Organics (Cleveland, OH, U.S.A.).…”

Section: Methodsmentioning

confidence: 99%

Activation of intestinal brush border guanylate cyclase by aromatic disulphide compounds

Eldeib

Parker

White

1991

Biochemical Journal

View full text Add to dashboard Cite

show abstract

“…The compounds 2 a and 3 a were identical with authentic samples of hypoxanthine and purine. Spectral (UV, IR), chromatographic (TLC, A, C) and analytical data of 4 a were identical with those of synthesized purine-6-sulfonic acid [10]. In another experiment the residue after the solvent removal was treated with 0.1 N HCl for 24 h. The solution was neutralized with aqueous NaOH and concentrated.…”

Section: Irradiation Of 1 Si In Tert-butanolmentioning

confidence: 60%

“…The products 4 a is thought to be a sulfonic rather than sulfinic acid. The UV (pH 4-12) and IR spectra of 4 a were identical with those of synthetized purine-6-sulfonic acid [10]. Satisfactory elemental analysis of 4 a (potassium salt) was obtained.…”

Section: £Er£-mentioning

confidence: 68%

See 1 more Smart Citation

Photolysis of Thiopurines in the Presence of Oxygen⁺

Wenska¹,

Paszỳc²

1981

Zeitschrift Für Naturforschung B

View full text Add to dashboard Cite

Abstract Irradiation (λ > 290 nm) of 6-thiopurine and some 9-substituted 6-thiopurines in oxygen saturated tert-butanol leads to hypoxanthine, purine and purine-6-sulfonic acid or their substituted derivatives. Purine and hypoxanthine formation can be sensitized with dyes. The reaction of 6-thiopurine with singlet oxygen has also been performed with purine and hypoxanthine among other products. It seems however that 1O2 is not an important intermediate in the photooxygenation. The photoreaction may have some synthetic value. Hypoxanthines (~50%) or purines (35-45%) were obtained depending on the solvent used.

show abstract

Polarography and Voltammetry of Nucleosides and Nucleotides and Their Parent Bases as an Analytical and Investigative Tool

Elving

O'Reilly

Schmakel

1973

Methods of Biochemical Analysis

View full text Add to dashboard Cite

Thiation of Nucleosides. III. Oxidation of 6-Mercaptopurines¹

Cited by 85 publications

References 4 publications

Activation of intestinal brush border guanylate cyclase by aromatic disulphide compounds

Activation of intestinal brush border guanylate cyclase by aromatic disulphide compounds

Photolysis of Thiopurines in the Presence of Oxygen⁺

Polarography and Voltammetry of Nucleosides and Nucleotides and Their Parent Bases as an Analytical and Investigative Tool

Contact Info

Product

Resources

About

Thiation of Nucleosides. III. Oxidation of 6-Mercaptopurines1

Cited by 85 publications

References 4 publications

Activation of intestinal brush border guanylate cyclase by aromatic disulphide compounds

Activation of intestinal brush border guanylate cyclase by aromatic disulphide compounds

Photolysis of Thiopurines in the Presence of Oxygen+

Polarography and Voltammetry of Nucleosides and Nucleotides and Their Parent Bases as an Analytical and Investigative Tool

Contact Info

Product

Resources

About

Thiation of Nucleosides. III. Oxidation of 6-Mercaptopurines¹

Photolysis of Thiopurines in the Presence of Oxygen⁺