Sulphonamides chemical

Sulphonamides were introduced by Domagk in 1935. It had been shown that a red azo dye, prontosil (Fig. 5.16B), had a curative effect on mice infected with /3-haemolytic streptococci it was subsequently found that in vivo, prontosil was converted into sulphanilamide. Chemical modifications of the nucleus of sulphanilamide (see Fig. 5.16A) e compounds with higher antibacterial activity, although this was often accompanied by greater toxicity. In general, it may be stated that the sulphonamides... 

Pyridazine-derived sulphonamide antibacterials, in particular sulphamethoxypyridazine, are still the subject of extensive investigations. Thus, for instance, in volumes 82 to 108 of Chemical Abstracts, there are more than 300 abstracts of papers dealing with compound (95, R1 = MeO R2 = H), which are not included in the present review due to space limitations. Only selected examples are mentioned. 

Fig. 14 Dependence of relative reactivity on (minimum) interatomic distance between the electrophilic centre and the carboxyl oxygen, for (a) sulphonamides [76] and (b) malonate half-esters [77]. Reprinted with permission from Jager et al. (1984). Copyright 1984 American Chemical Society.

Sulphonamides were supplied by Sigma (Sigma Chemical Company, St. Louis, MA 63178 USA) Sulphisomidine (SOMI), Sulphathiazole (THIA), Sulphamethizole (METH), Phtalylsulphacetamide (FTAL), Sulphacetamide (ACET), Sulphapyridazine (PYRI), Sulphamerazine (MERA), Sulphamethoxypyridazine (MEPY) and Sulphachloropyridazine (CLPY). 

Suggest, by means of chemical equations, one route for the introduction of each of (i) an acid residue and (ii) a basic residue into the structure of 4-hydroxybenzenesulphonamide when the sulphonamide group acts as the pharmacophore in this compound. 

In sulphonamides, the 33S chemical shift is sensitive to the electronic properties of both the a-group and of the substituent on the nitrogen atom.64 The replacement of both hydrogen atoms of the -NH2 moiety with methyl groups induces a downfield shift of 23 ppm, and the substitution of one hydrogen bond with another NH2 group causes a downfield shift of 18 ppm. 

Acetylation is an important metabolic route for aromatic and heterocyclic amines, hydrazines and sulphonamides. An amide bond is formed between the amino group of the chemical and the acetate. This reaction is catalyzed by acetylases, the acetyl group being donated by acetyl CoA. 

Methaemoglobinaemia may be induced by oxidising drugs sulphonamides, nitrites, nitrates (may also occur in drinking water), primaquine, -caine local anaesthetics, dapsone, nitrofurantoin, nitroprusside, vitamin K analogues, chlorates, aniline and nitrobenzene. In the rare instance of there being urgency, methylene blue 1 mg/kg slowly i.v. benefits within 30 min. (Ascorbic acid competes directly with the chemical cause but is inadequate in severe cases, which are the only ones that need treatment.)... 

Sevredol morphine, sezolamide [inn] (sezolamide hydrochloride [usan]) is chemically a sulphonamide, a CARBONIC ANHYDRASE INHIBITOR, and can be used in antiglaucoma treatment. 

Sulfones are chemically related to sulphonamides, and are presumed to work by a similar mechanism. The only one still in clinical used is dapsone and this is used in combination with other drugs to treat leprosy. See antileprotic AGENTS. 

The chemical nature and related physicochemical properties largely govern the distribution and elimination, which refers to biotransformation (metabolism) and excretion, of antimicrobial agents. The majority of antimicrobial agents are weak organic electrolytes, either weak acids (penicillins, cephalosporins, sulphonamides) or weak bases (aminoglycosides, lincosamides, macrolides, diaminopyrimidines, metronidazole), while fluoroquinolones, tetracyclines and rifampin are amphoteric compounds, and chloramphenicol and its... 

While the search of new antimalarials was still on, Schoenhoefer [36] proposed that the antimalarial activity of aminoquinolines was due to their ability to exist in tautomeric forms. This observation and the fact that sulfapyrimidines possess antimalarial activity was exploited by Curd and Rose working at Imperial Chemical Industries in the UK. These workers selected 4-aminopyrimidines (25) for molecular modifications on two counts (a) such a skeleton is present in various antimalarial sulphonamides, and (b) they exist in the tautomeric structures similar to 4-aminoqui-nohne antimalarials [37-40]. 

To compare the effect of carbazole component of sulphonamides on light stabilizing activity there has been carried out their synthesis on the basis of coke-chemical indan (Table 21). 

Proton NMR chemical shifts for some sulphonamides are given in Table 23. Figure 4 shows graphically the NMR chemical shifts for some sulphonamide drugs81 (not all... 

TABLE 23. NMR chemical shifts for some sulphonamides, RS02NR2... 

TABLE 24. 13C NMR chemical shifts of some sulphonamides, RS02NR ... 

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