Sulfonylurea structure

Die cytosolic loop between TMs 13 and 14 (KCO I) and TMs 16-17 (KCO II) were identified as critical for KatpCO binding to SURs (Fig. 4d). T1286 and Ml 290 appeared to be particularly important. Close local association of sulfonylurea and KCO binding regions might represent the structural basis for negative allosteric coupling of the sites. 

Sulfonylureas are the basis of a large group of herbicides. Cytochrome P450 enzymes in Streptomyces griseolus transform the sulfonylureas by hydroxylation (Omer et al. 1990) leaving the -SO2NHCONH- part of the structure unaltered (Harder et al. 1991). 

Various substituted sulfonylurea derivatives, partly in use as diabetes drugs, have been coordinated to Cd and Hg. Besides the IR and [H NMR spectra of several species, the structures of one each of the Cd and Hg compounds have been solved.155 In the Cd complex three ligands act as... 

It is noteworthy that sulfanilamide structural modifications have led to other valuable classes of drugs already discussed, including the hypoglycemic sulfonylureas and the diuretic carbonic anhydrase inhibitors. 

Berger and Wolfe (1996) reported a correlation of hydrolysis data for 12 sulfonylurea herbicides. The use of bond strength or Hammett a constants was impossible because of the complex structures of the compounds. The hydrolysis pathways for this class of compounds are also more complex, but the use of quantum mechanical parameters provided the detailed structural information needed to develop a useful correlation. As a result of the many different functional groups, several reaction pathways are available depending on the substituents. Also, there is a complicating pH effect on the pathways and the kinetics of hydrolysis as shown by product studies. The 12 herbicides used in this study are listed in Table 13.4, and the pseudo first-order hydrolysis rate constants are given in Table 13.5. Figure 13.2 shows the basic structure of these compounds. 

Generic chemical structure of sulfonylurea herbicides Berger and Wolfe (1996) studied. 

B.M. Berger, M. Muller, A. Eing, Quantitative structure-transformation relationships of sulfonylurea herbicides, Pest Manage. Sci. 58 (7) (2002) 724-735. 

Pharmaceuticals and Agrochemicals. ThioglycoHc acid and its esters are useful as a raw material to obtain biologically active molecules. In cephalosporine syntheses, (4-pyridyl)thioacetic acid [10351-19-8] (65) and trifluoromethane (ethyl) thioglycolate [75-92-9] (66) are used as intermediates. Methyl-3-amino-2-thiophene carboxylate can be used as intermediate for berbicidal sulfonylureas (67) and various thiophenic structures (68). 

Acetolactate synthase (ALS, EC 4.1.3.18) is the first common enzyme in the biosynthetic route to the branched chain amino acids, valine, leucine and isoleucine. It is the primary target site of action for at least three structurally distinct classes of herbicides, the imidazolinones (IM), sulfonylureas (SU), and triazolopyrimidines (TP) (Figure 1). SU and IM were discovered in greenhouse screening programs whereas TP was subsequently targeted as a herbicide. Numerous substitution patterns can be incorporated into the basic structure of all three classes of herbicides to provide crop selectivity as well as broad spectrum weed control. This is amply demonstrated in the seven products based on SU and four based on IM already in the market. A number of others are in various stages of development. The rapid success of ALS inhibitors as herbicidal products has attracted a world-wide research commitment. Not since the photosystem II... 

Repaglinide possesses the same mechanism of action as the sulfonylureas but differs in chemical structure. After oral administration, the effect develops rapidly and fades away quickly. Therefore, repaglinide can be taken immediately before a meal. 

Acute thrombocytopenia is rarely associated with the newer sulfonamides (4,93,94). The structurally related sulfonylureas and thiazide diuretics can also cause allergic thrombocytopenia (95). Although some in vitro tests have been reported to predict the occurrence of thrombocytopenia, none of these has been used routinely (96,97). Furthermore, a negative test result with a drug does not definitely exclude it as the responsible allergen. 

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