Thiamine Propyl Disulfide Research Articles

Thiamine Derivatives of Disulfide Type. XIV. Kinetic Studies on the Reaction between Thiamine and Propyl Propane-Thiolsulfinate or -Thiolsulfonate

Kinetic studies were conducted on the reaction between thiamine and propyl propane-thiolsulfinate (PrSSOPr) or -thiolsulfonate (PrSSO2Pr) to give thiamine propyl disulfide (B1SSPr). The folllowing mechanisms were suggested for the reaction with PrSSOPr. [chemical formula] (1) B1SH+PrSSOPr→^^(k5)B1SSPr+(PrSOH) (2) [chemical formula] (3) The reaction with PrSSO2Pr was more complicated, since the hydrolysis of PrSSO2Pr was not neglected, as shown in the following equations. B1SH+PrSSO2Pr→^^(k3)B1SSPr+PrSO2H (4) PrSSO2Pr+H2O→^^(k4)(PrSOH)+PrSO2H (5) The rate of conversion to thiol-type thiamine was found to be the rate limiting step and k1 determined as 1.66×10-4 sec-1 at pH 8 and 37°. The validity of the discussion was supported by the agreement between the experimental data and the simulation curves by analog computation.

A new vitamin preparation, thiamine propyl disulfide and other disulfide derivatives of thiamine

A new vitamin preparation, thiamine propyl disulfide and other disulfide derivatives of thiamine

Correction of Thiamine Depletion Syndromes Refractory to Oral Thiamine Hydrochloride.

Excerpt Malabsorption of commercially available thiamine preparations is often responsible for clinical and laboratory evidence of a deficiency of this vitamin. Studies of thiamine propyl disulfide...

Uptake of thiamine propyl disulfide in Escherichia coli.

Properties of a system of thiamine propyl disulfide (TPD) uptake have been investigated in Escherichia coli. It was found that the cells incubated with TPD in the presence of glucose at 37° accumulated thiamine pyrophosphate in the cytoplasm with a negligible amount of TPD. TPD in the reaction medium remained practically in the unchanged form after incubation with the cells for 30 minutes at 37°. Thiamine pyrophosphate accumulation in TPD uptake was an energy- and temperature dependent process which follows Michaelis-Menten kinetics; apparent Km was 3.0×10-6 M and Vmax was 3.5×10-5 moles per minute per g dry weight of the cells.Treatment of the cells with N-ethylmaleimide resulted in inhibition of the rate of thiamine pyrophosphate accumulation much stronger in TPD uptake than that in thiamine uptake. A thiamine transport-negative mutant of E. coli which is defective in the “carrier” protein specific for thiamine, did not accumulate thiamine pyrophosphate when incubated with TPD.These results strongly suggest that in E. coli TPD is not directly taken up by the cells but is first reduced to thiamine on the outer surface of the cell membrane probably by a non-enzymatic process. Thiamine thus formed is transported via the uptake system specific for thiamine; the “carrier” protein functions for passage through the membrane and membrane thiamine kinase functions to accumulate thiamine as thiamine pyrophosphate in the cytoplasm.

Pharmacokinetics of thiamine derivatives. II. Elimination of thiamine derivatives from the blood of rat.

Some thiamine derivatives were compared pharmacokinetically about their elimination from blood after intravenous injection in rat. TPD (thiamine propyl disulfide), CCT (cyclocarbothiamine) and BTMP (S-benzoylthiamine monophosphate) were used as the typical thiamine derivatives. 1) It was found that the rates of conversion of TPD and CCT to thiamine in blood were rapid, but that of BTMP was slow. 2) TPD formed thiamine mainly through erythrocytes, but CCT formed thiamine mainly through plasma. 3) Volume of distribution (Vd or V1) of TPD, BTMP, CCT and thiamine were 37.6, 93.5, 187.5 and 256.1 ml, respectively. After intravenous injection of TPD, BTMP, CCT and thiamine rate constants of elimination of thiamine (keI or k'el) were 0.145, 0.151, 1.61 and 1.98 hr-1 respectively. Elimination constant of TPD was nearly equal to that of BTMP, and that of CCT to that of thiamine. 4) TPD and CCT behaved almost same in blood in vitro, except elimination of them from blood. 5) Since both TPD and BTMP were considerably taken up into erythrocytes, and also their elimination constants were equal to each other, the elimination constant must mean the constant of transfer rate from erythrocytes to plasma. 6) Pharmacokinetic model was proposed for each derivative.

Pharmacokinetics of thiamine derivatives. I. Formation of thiamine from thiamine propyl disulfide by erythrocytes of rat.

The processes of uptake of TPD (thiamine propyl disulfide) and formation of thiamine were investigated in detail, using the suspension of rat erythrocytes, since erythrocytes were most effective to form thiamine from TPD in blood. 1) The ratio of amount of thiamine formed in erythrocytes to that in the suspension medium was 1 : 1 after incubation of TPD in erythrocytes suspension. This ratio did not change remarkably, even when amount of erythrocytes was increased by 100 fold. 2) It was verified that TPD was converted to thiamine in the membrane under the influence of reducing compounds in erythrocytes and thiamine, which was formed there, went out and into erythrocytes with equal probability. 3) Process of formation of thiamine from TPD by erythrocytes was expressed by second order rate reaction kinetics, and its rate constant was determined.

Action of thiamine tetrahydrofurfuryl disulfide on the isolated clam heart.

1. The action of thiamine tetrahydrofurfuryl disulfide (TTFD) on the excised heart of clam (Meretirx meretrix lusoria) was investigated.2. TTFD displayed a striking postive inotropic action. This action did not appear in Ca-free or Na-free solution, but appeared in K-free solution.3. TTFD antagonized the negative inotropic action of acetylcholine.4. These actions of TTFD were closely similar to those of thiamine propyl disulfide and these actions may be ascribed to -N-CHO -C-CH3=C in the structure.

On the Uptake of Thiamine Propyl Disulfide by Escherichia coli

On the Uptake of Thiamine Propyl Disulfide by Escherichia coli

The fate and urinary metabolites of thiamine propyl disulfide in rabbit and man

The metabolic fate of the propyl mercaptan moiety of thiamine propyl disulfide (TPD) has been studied in rabbit and man for comparison with the previous results obtained with rat. About 70–80 per cent of the radioactivity was excreted into the first 48 hr urine, when 35S-labeled TPD was administered to rabbits by either s.c., i.v. or p.o. route. More than 90 per cent of the urinary metabolites was identified as methyl propyl sulfone (MPS), 2-hydroxypropyl methyl sulfone (2-HPMS), 3-hydroxypropyl methyl sulfone (3-HPMS), methylsulfonyl propionic acid (MSPA) and inorganic sulfate. Following oral administration, inorganic sulfate and MSPA were the predominant products, accounting for about 70 per cent of the urinary metabolites. On the other hand, MPS, 2-HPMS, MSPA and inorganic sulfate were excreted in approximately equal amounts (20–28 per cent) after parenteral administration. Time course changes on metabolites composition were also studied. In the urine of the healthy men who received TPD, was also confirmed the occurrence of MPS, 2-HPMS and 3-HPMS by the isotope dilution method. These results show that there are little species differences among rat, rabbit and man in the metabolism of the propyl mercaptan moiety of the drug.

Action of thiamine and related compounds on isolated clam heart.

1. The action of thiamine and related compounds on the isolated heart of clam (Meretrix meretrix lusoria) was investigated.2. S-benzoylthiamine (SBT) and thiamine propyl disulfide (TPD) among these related compounds displayed a very remarkable positive inotropic action, whereas thiamine, acetylthiamine, thiamine diphosphate, thiamine triphosphate, benzoylthiamine monophosphate and ATP did not practically display any clear action.3. SBT and TPD showed a remarkable antagonistic action against the negative inotropic action of acetylcholine, but have no effect on the action of 5-hydroxytryptamine.4. The positive inotropic action of SBT and TPD was retained in K-free medium, but it completely disappeared in Na-free or Cafree medium. When more or less Na+ or Ca2+ was present in the medium, the action of SBT and TPD appeared as in the normal medium.5. The positive inotropic action of SBT and TPD, therefore, is believed to be closely related to the transport system of the cellular membrane of the clam heart muscle, in which Na+ and Ca2+ are involved.

Thiamine derivatives of disulfide type. I. Formation of thiamine from thiamine propyl disulfide in rat intestine in vitro.

The conversion of thiamine from thiamine propyl disulfide was studied in vitro using rat intestine set at a modified Wiseman and Smyth's apparatus. The following conclusions were drawn from the experimental results obtained. 1) It was found that thiamine propyl disulfide was converted to free thiamine in mucosal solution and that propyl disulfide appeared in intestinal tissues during the conversion. 2) The formation of thiamine in mucosal and serosal solutions followed the first order kinetics apparently and were same magnitude. 3) The conversion may be considered as the coupled reactions between chemical and enzymic systems and the participation of glutathione reductase to this conversion was expected.

Thiamine derivatives of disulfide type. 3. Enzyme systems in rat intestine contributed for thiamine formation from the disulfide type derivatives.

Assuming glutathione (GSH) as the main part of thiol group contributing for thiamine formation in gut wall from disulfide type derivatives, i.e., thiamine propyl disulfide (TPD) and thiamine disulfide (TDS), the reactivity between GSH and TPD or TDS and the characteristics of enzyme system in gut wall was studied. The following conclusions were drawn from the result presented. 1) The rate constant determined at 37° and pH 7.4 was 9.83×102 for TPD and GSH, 3.7×10 for GSH and glutathione propyl disulfide, 1.78×103 for GSH and TDS, and 3.72×103 for GSH and thiamine glutathione disulfide in liter/mole min, respectively. 2) The enzyme preparation was obtained by dialysis of rat gut wall homogenate. The activity was examined under the presence of GSH and NADPH and Km=6.25×10-5 M/liter and optimal pH=7.4 were same as that of glutathione reductase from rat liver. 3) The mechanism proposed for thiamine formation in gut lumen confirmed as the coupled system shown by Eq. (1), (2), and (3).

X-Ray Analysis of Thiamine Propyl Disulfide

The crystal structure of thiamine propyl disulfide (TPD) was determined by the three dimensional Patterson superposition method and by application of least squares treatment and Fourier syntheses. The unit cell is monoclinic, space group P21/a, with a=21.04, b=11.35, c=8.53 A and β=101°36'. The propyl disulfido group has been found to lie cis to the N-formyl group, the result being consistent with the hitherto proposed structure for TPD. The structure of the pyrimidine portion was discussed in comparison with the results of earlier workers. The stereochemical structure of TPD and a unique hydrogen bonding in the crystal were also discussed.

Thiamine Derivatives of Disulfide Type. VIII. The Exchange Reaction between Thiamine Propyl Disulfide and the Various Thiols

The exchange reactions between TPD and polyfunctional thiols such as glutathione, 2-aminoethylmercaptan, 2-hydroxyethylmercaptan and 2-carboxyethylmercaptan were examined under an anaerobic condition. The following conclusions were drawn from the results presented. From an analysis of the pH-rate profile of the reactions between TPD and thiols containing the amino group in a molecule, the reaction was revealed as the combination of the following three reactions through the pH range of 3 to 12, HB1SSPr + NH3+RS-→HB1S- + NH3+RSSPr B1SSPr + NH3+RS-→B1S- + NH3+RSSPr B1SSPr + NH2RS-→B1S- + NH2RSSPr where HB1SSPr is the protonated form of TPD, NH3+RS- is the protonated amino-thiol anion, HB1S- is the protonated thiamine and NH3+RSSPr is the protonated amino-alkyl propyl disulfide. On the other hand, in the reaction between TPD and thiol, 2-hydroxyethylmercaptan, the following two reaction equations were presented through the experimental pH range of 3.5 to 12.0. HB1SSPr + RS-→HB1S + RSSPr B1SSPr + RS-→B1S + RSSPr The second order rate constants of individual reactions were determined. The activation energies of these reactions obtained were about 10 kcal mole-1, and the values of activation entropies were 5 to 24 cal mole-1 deg-1. These second order rate constants were correlated with the pKa values of the thiol group with Bronsted equation, log k=αpKa + C, with a resultant very large α value. From this relationship, it may be concluded that these thiols are an extremely good nucleophile to the disulfide bond and especially to protonated TPD.

Antithiamine Activity of Dimethialium and Its Mode of Action

The antithiamine activity of dimethialium, a thiamine analogue having a methyl group in place of the hydroxyethyl group in the thiazole moiety, has been demonstrated in nutritional assays using rats or chicks. The antagonism was evident only when thiamine was administered orally. The inhibition was competitive with thiamine or thiamine propyl disulfide. The latter counteracted the antithiamine activity of dimethialium two to four times more effectively than did thiamine. Thiamine uptake in vitro by Ehrlich ascites carcinoma cells was inhibited competitively by dimethialium, whereas the uptake of thiamine tetrahydrofurfuryl disulfide was not affected. Dimethialium inhibited thiaminokinase competitively with thiamine but showed little or no effect upon pyruvate decarboxylation by carboxylase or pyruvate oxidase complexes. All these results demonstrate that dimethialium is a typical but relatively weak antithiamine whose antagonistic activity is far less than that of pyrithiamine and comparable to that of amprolium. The present data also support the view that the primary cause of the antithiamine action is its interference with intestinal absorption or cellular uptake of thiamine.

EFFECTS OF THIAMINE PROPYL DISULFIDE ON TRYPTOPHAN PYRROLASE IN RATS

The formation of complex between protein and thiamine propyl disulfide (TPD) has been studied by many investigators. Higher radioactivity in rats treated with TPD-S35 (outer) was found in blood (1), and when venous blood of normal healthy rabbit was incubated with TPD-S35 (outer), the radioactivity was concentrated in serum albumin fraction (2). As illustrated in Fig. 1, TPD contains S-S bond which is reduced to produce both propylmercapto moiety and thiol type of thiamine. Utsumi et al. (3) indicated the formation of complex between albumin and propylmercapto moiety dissociated from TPD, and their successive paper (4) described binding of TPD to bovine serum albumin. Reduction of TPD in incubation with blood cell was responsible for SH groups in blood (5), and Kawasaki el al. (6) suggested the binding between TPD and SH enzymes, papain and alcohol dehydrogenase. On the other hand, recent studies by Maeno and Feigelson (7) have shown the chemical properties of the reductive activation of liver tryptophan pyrrolase (TP) by ascorbate, GSH and dithiothreitol, and implicated that one or more SH groups were involved in TP as binding site for tryptophan. In the previous paper (8), six thiamine derivatives, i.e., thiamine-mono, -di and -triphosphate, S-benzoylthiamine-mono, -di and -tri phosphate were used to examine their effects on TP in the mechanism of energy dependent activation by ATP-Mn++ system reported by Pitot and Cho (9) and no significant effects were observed. It seemed possible to speculate that these phosphates of thiamine or S-benzoylthiamine have little effect on TP because of involving no S-S groups in their molecules. Since preliminary experiments with homogenate showed that effects of TPD on TP varied on pH of the incubation mixture, the purpose of the present study is to investigate the effects of TPD on TP.

Electrophysiological study on the effect of several drugs on the free wall of the right ventricle in dogs with pulmonary stenosis.

Eight mongrel dogs were operated to produce pulmonary stenosis. Eight weeks after the operation, the free wall of the right ventricle with myocardial lesions was excised and a strip of the muscle was prepared for this study. The preparations immersed in oxygenated Tyrode's solution were given several drugs, such as Thiamine pyrophosphate (Cocarboxylase), Thiamine Tetrahydrofurfuryl Disulfide (TTFD), Thiamine Propyl Disulfide (TPD), Thimamine hydrochloride. Adenosine Triphosphate (ATP) and Desacetyl-lanatoside C (Lanatoside C). The effect of these drugs on specimens were observed electrophysiologically regarding transmembrane action potential, its duration and contractile tension as compared with the normal heart muscle.

Comparison of turnover of thiamine propyl disulfide and thiamine in various organs on oral or parenteral administration to rats.

Turnover of thiamine in various organs was investigated by giving TPD-35S (inner) or thiamine-35S by mouth or by subcutaneous injection to white rats and the following results were obtained:1. The turnover ratio of thiamine in the organs was increased day by day after daily oral administration or subcutaneous injection of TPD-35S (inner) or thiamine-35S.2. The turnover ratio of thiamine in the organs was distinctly higher after administration of TPD-35S (inner) by either route than in the case of thiamine-35S.3. No marked difference in the turnover ratio due to difference in the route of administration, oral or subcutaneous, of both TPD and thiamine was noted.

Thiamine Derivatives of Disulfide Type. V. Kinetic Studies of the Reaction between Thiamine Propyl Disulfide or Homologes and L-Cysteine

The Kinetics between thiamine propyl disulfide or its homologes and L-cysteine were studied under the experimental conditions determined in the preceding paper. The effects of alkyl substitution of TPD on kinetic parameter were also studied, using thiamine benzyl disulfide, thiamine allyl disulfide, and thiamine hydroxyethyl disulfide. The following conclusions were drawn from the results presented. 1) From an analysis of the pH-rate profile of the reaction which followed a second order kinetics throughout the pH range of 3.5 to 13.2, the reaction was revealed as the combination of the following elementary reactions. [numerical formula] where HG1-SS-Pr is the protonated form of TPD, NH3+-Cy-S- is protonated cysteine anion, and k1, k2 and k3 are specific rate constants of individual elementary reactions. The values determined were 1.82, 0.261 and 1.10 in 104L. mole-1 min. -1for k1, k2 and k3, respectively. 2) No detectable effect of ionic strength and buffer concentration on the rate constant was observed at pH 4.0 on Reaction (I). 3) The activation energy obtained from an Arrhenius type plot was 12.3 and 10.9 kcal./mole for Reaction (I) and (II) after correction for ionic dissociation of thiol and amino groups in cysteine. 4) From the kinetic data tabulated on TPD derivatives, the order of the reactivity was TBD>TAD-TOED>TPD. The activation energies of Reaction (I) were about 10 to 12 kcal./mole.

Thiamine derivatives of disulfide type. IV. The exchange reaction between thiamine propyl disulfide and L-cysteine.

Experimental conditions for the kinetic study of exchange reaction between thiamine propyl disulfide (TPD) and L-cysteine were examined where the possible side reactions shown in Chart 1 proved by thin-layer chromatography could be safely ignored. The following conclusions were drawn from the results obtained. 1) It was proved that the formation of thiamine was the main product and the formation of propylmercaptan was negligible when the reactants were mixed in a molar ratio of 1 : 1 and an initial concentration of 1×10-3∼5×10-5 molar. 2) The exchange reaction followed second order kinetics examined from half-life, the plot of integrated equation, and the result of pseudo first order reaction converted by experimental conditions. The rate constants observed were 1.723 and 444.4 L. mole-1 min. -1at 15°and pH 4.6 and 8.0, respectively. 3) The rate constant of the thiamine formed from TPD and propylmercaptan which was the largest side reaction among the various possibilities, was 0.607 L. mole-1 min. -1 at pH 4.6 and 15°as a second order reaction.