Sulfonamide inhibition constants

The biological activity A = log II50 was measured on bovine erythrocyte B. The inhibition constants, logllso, normalized with respect to p-amino-benzensul-fonamide, represent on a logarithmic scale how many times a given heterocyclic sulfonamide is more active than the reference compotmd, namely p-amino-benzensulfonamide. The experimental data are from Menziani and De Benedetti (1992). 

Seydel (1966) has shown that there is an approximate linear relationship between Hammett <7-values for various benzeneamines (related to the sulfonamides) and the logarithm of the lowest concentration of a sulfa drug to show inhibition of bacterial growth. The more positive the Hammett ortho-halogenated amine, which proved to give a more active sulfonamide than could be expected from its Hammett [Pg.403]

From the kinetic study o/lb-catalyzed hydrolysis of 4-nitrophenyl acetate inhibited by various aromatic sulfonamides, the apparent 1 1 affinity constants were determined at jH 8.4/ A comparison o/intramolecular Kntra=10 =Wor ll)/i (for la)]ond intermolecular for la with / toluenesulfonamide) contribution of p-toluenesulfonamide anion coordination to the zinc(II)-[12]aneN3 complex gives an effective mo-larity M by the intramolecular location. 

These i l anion complexation constants for the zinc(II) macrocyclic triamine complexes with various aromatic sulfonamides exhibit a trend paralleling that reported for suggesting a similar inhibition mechanism [i.e., the deprotonated sulfonamide anions can coordinate to the zinc(II) in aCA-active center].The effectivemolarity of the pendant sulfonamide in the model complex may be viewed as the noncoordinating contributions to bring the inhibitors to the zinc(II) center ofCA. 

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