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The antimetabolite sulfanilamide inhibits sporulation in Saccharomyces cerevisiae strain AP1. Cells exposed to sulfanilamide at various times during the sporulation process become progressively insensitive to the drug, although accumulation of sulfanilamide by the cells increases with time. Vegetative growth of AP1 is practically unaffected by sulfanilamide; pregrowth of the cells in the presence of the drug does not prevent sporulation. Thus, inhibition is confined to the meiotic phase of the cell cycle. Sensitivity to sulfanilamide is independent of pH. Increasing the time cells are exposed to sulfanilamide results in a progressive reduction of ascus formation; however, the inhibition is reversible since sporulation can occur in cells exposed to the drug for greater than 24 h. The drug arrests the cells at a point before commitment to sporulation, since yeast cells exposed to sulfanilamide for 12 h do not complete the sporulation process when returnedto vegetative medium, but resume mitotic growth instead. Meiotic nuclear division is largely prevented by sulfanilamide, and synthesis of RNA and protein is severely retarded. DNA synthesis is inhibited up to 50%; glycogen synthesis is approximately 90% inhibited. Other yeast strains showed varying sensitivity to sulfanilamide; homothallic strains were generally less affected.
9 derivatives of sulfanilamide were tested for anticonvulsant properties against electroconvulsive shock in mice and rats and against pentylenetetrazole shock in mice. Reference standard in these tests was sulfanilamide. Their toxic, analgesic and sedative activities were also examined. The anticonvulsive activity of sulfanilamide could be enhanced by substitution of the phenyl ring with a halogen atom. Substitution of the sulfonamide group diminishes the anticonvulsant and increases the sedative activity of sulfanilamide. Detoxication of the basic substance by substitution of the aromatic amino group only little influences the anticonvulsant activity and may even enhance it. Of the tested substances, 1742 (3-chloro-4-phenacetamido-benzene-sulfonamide) exhibited the best anticonvulsant activity; slightly weaker was PB 311 (3-chloro-4-amino-benzene-sulfonamide). The ED50 for the activity against electroconvulsive shock of both substances was about 30 mg/kg p.o. in mice. The relationship between anticonvulsant activity and inhibition of the renal and cerebral carbonic anhydrase is discussed.
By using the "turned inside out bag" technique and brough tests with homogenates it was found that sulfanilamide is susceptible to acetylation in a larger measure than sulfocarbamide and sulfacylum natrium. In tests with isolated lengths of the small intestine phenobarbital (in doses of 25 mg/kg for 5 days) weakened acetylation of sulfanilamide and sulfocarbamide and did not change acetylation of sulfacylum natrium. Acetylation of all these three sulfanilamides in homogenates of the liver, blood and the small intestine mucosa did not change under the effect of phenobarbital.
The fusion of certain sulfanilamides with benzhydrol in the presence of anhydrous zinc chloride affords several different products, depending primarily on the temperature at which the reaction is carried out. With sulfanilamide itself, three different products were isolated at 100, 160, and 180 degrees. A sequence of steps is suggested to account for the three products, one of which involves an intramolecular rearrangement of a benzhydryl moiety. The fusion of benzhydrol with p-toludine gives 2,6-dibenzhydrylaniline and not the N,N-dibenzhydryl derivative as previously reported.
The thermodynamic properties of the adsorption of sulfanilamide, phenol and n-butanol on Bio-Gel beads have been studied. Bio-Gel was chosen as the adsorbent as it possesses both hydrophobic and hydrophilic sites on its surface. Adsorption of the former two adsorbates was found to be exothermic, and the relevant thermodynamic parameters at 20 degrees are in the ranges: deltaH degrees = -2.7 to -5.4 kcal/mole; deltaF degrees = -6.0 to -7.6 kcal/mole; deltaS degrees = +7.7 to +11.6 e.u. In the presence of urea, adsorption of sulfanilamide and phenol was partially disrupted. This, together with the large entropy gain of the process, indicates that both hydrogen bonding and hydrophobic bonding contribute cooperatively to the adsorption. On the contrary, adsorption of n-butanol, which was not susceptible to urea, was an endothermic process with the parameters, deltaH degrees = +5.8kcal/mole, deltaF degrees = -1.8 kcal/mole, and deltaS = +26.1 E.U. at 20 degrees. These data conform to the thermodynamic properties of hydrophobic bond formation. Finally, possible implications of these data in the structural assembly of lipoprotein molecules are discussed.
We have previously suggested the involvement of both hydrogen binding and hydrophobic bonding in the adsorption of sulfanilamide on Bio-Gel beads. In the present study, we closely examined the concentration dependence of the binding curve and our proposed binding model has been corroborated. For comparison, binding parameters and thermodynamic data pertaining to the sulfanilamide-Sephadex system have been also evaluated.
Nonconjugative plasmids encoding sulfanilamide (Sa) resistance were demonstrated at a high frequency in Shigella and Escherichia coli strains resistant to sulfanilamide. These Sa plasmids were all compatible with the standard plasmids used in compatibility testing. The sizes of seven Sa plasmids were measured by electron microscopy and ranged from 1.79 to 2.08 mum, corresponding to 3.5 to 3.9 megadaltons.
Suspensions of isolated liver cells were prepared from rat livers perfused with Ca++-free buffer and 0.05% collagenase. Primary cell suspensions (containing both parenchymal and nonparenchymal liver cells) metabolized sulfadimidine, sulfanilamide, p-aminobenzoic acid, and isoniazid approximately at first order kinetics for at least 4 hr. Suspensions of parenchymal cells had the same metabolic capacity, although the metabolism of isoniazid proceeded at a somewhat reduced rate compared to the primary cell suspensions. Suspensions of nonparenchymal cells did not metabolize sulfadimidine, sulfanilamide, or p-aminobenzoic acid during 4 hr, although such suspensions acted upon isoniazid to some degree. It was concluded that parenchymal rat liver cells may metabolize (acetylate) all four drugs tested, whereas nonparenchymal cells metabolize only isoniazid to any considerable extent.
The topography of the active sites of human erythrocyte carbonic anhydrases B and C and bovine erythrocyte carbonic anhydrase B was studied using a series of spin-labeled sulfanilamide analogs. Results show that the active site of human carbonic anhydrase C is a narrow cleft approximately 14 A in depth. This observation is in good agreement with previously published X-ray diffraction data. While the active sites of human carbonic anhydrase B and bovine carbonic anhydrase B have the same general shape as the active site of human carbonic anhydrase C, they are slightly deeper.
The effect of ethanol of blood levels of free and conjugated sulfonamides (sulfanilamide and sulfapyridin) and isoniazid was investigated in mice. Ethanol (1.5 and 4 mg/g i.v.) enhanced the amount of conjugated isoniazid without affecting the total amount of isoniazid in blood, and tended to raise the total amount of the sulfonamides.
Intramolecular interactions in N1-substituted sulfanilamides (SA) can rationalize the trend of their antibacterial powers with the use of a resonance scheme, derived from d orbital symmetry and tested with an extensive spectroscopic investigation on amidic, imidic, and anionic SA. On quantitative grounds, a good relationship is presented between the antibacterial power and the proton chemical shift of the p-amino group. The electronic features for high activity are described.
Dihydropteroate synthetase (DHPS) is specified by a substrain of Escherichia coli K12, ML1410. This enzyme activity is inhibited by sulfanilamides (Sa) and is known to be heat-stable, i.e., an Sa-sensitive normal enzyme. Another DHPS activity specified by E. coli ML1410 carrying drug resistance plasmids is Sa-resistant but heat-sensitive, i.e., an Sa-resistant enzyme. Most plasmids encoding single Sa or double (Sa. Tc or Sa. Sm) (Tc, tetracycline; Sm, streptomycin) resistance mediate the formation of this type of DHPS. Therefore, E. coli carrying these plasmids becomes diploid for DHPS, i.e., an Sa-resistant and an Sa-sensitive normal enzyme. The biochemical mechanism of Sa resistance mediated by plasmids encoding triple (Cm.Sm.Sa; Tc.Sm.Sa) and quadruple (Cm.Tc.Sm.Sa) resistance is not due to the formation of an altered DHPS but probably due to the decrease in permeation of the drug into the cell. The evolutionary process of the formation of Sa-resistance determinants on plasmids is discussed based on the presence of two types of Sa resistance mechanism.
All guinea pigs sensitized to sulfanilamide or 4-hydroxylaminobenzenesulfonamide in the absence of ultraviolet irradiation exhibited positive skin reactions to 4,4'-azoxybenzenedisulfonamide, 4-nitrosobenzenesulfonamide, and 4-hydroxylaminobenzenesulfonamide.
By CNDO (Complete Neglect of Differential Overlap) molecular orbital method, interatomic distances and XYZ cartesian corrdinates were calculated in five polymorphs (monohydrated, alpha, two beta, and gamma) of sulfanilamide. Interatomic distances thus obtained are very close to those originally presented by Bells & Roblin and support the mechanism of action postulated long algo for sulfa drugs as being competitive antagonism with p-aminobenzoic acid.
The preparation of quaternary ammonium derivatives of sulfanilamide and of tertiary amines containing an aliphatic chain up to c-18 is described. Some members of this series show greater antimicrobial activity than the parent substances. This is found also in comparison with other analogous series which have been prepared.
Three groups of patients suffering from diabetes mellitus with secondary sulfanilamide resistance (SS) were observed. The first group was given sugar-lowering drugs since the disease was diagnosed, the second group -- insulin plus hypoglycemic drugs, the third group -- insulin injections. The patients were followed up for 6-10 years, from the time of SS development -- 4.6 years. Stable compensation of diabetes mellitus was better achieved with combined therapy including sugar-lowering drugs per os and insulin, a dose of insulin being less by 22 units than in patients on insulin only. Progression of diabetic angiopathies was also less noticeable in the second group on combined therapy. The most unfavorable course of diabetic angiopathies and their progression were observed in the first group on sugar-lowering drugs per os.