Enzymatic reactivity, correlation with

Bolton, J. L. Valerio, L. G. Thompson, J. A. The enzymatic formation and chemical reactivity of quinone methides correlate with alkylphenol-induced toxicity in rat hepato-cytes. Chem. Res. Toxicol. 1992, 5, 816-822. 

Prolonged residence in the intestine or urinary bladder lumen could allow time for significant reaction with tissue components however, N-glucuronyloxy-AAF was only weakly carcinogenic at local subcutaneous sites of application (89). Enzymatic deacetylation to N-glucuronyloxy-AF has been detected in hepatic tissue but this activity in different species does not correlate with their relative susceptibility to AAF hepatocarcinogenesis (94). On the other hand, the alkaline pH-induced conversion to a reactive derivative may play an important role in urinary bladder carcinogenesis (87) by AAF and other arylamides in those species or individuals where normal urine pH is alkaline (e.g. normal rabbit urine pH is 8.5-9.0). 

Although a good correlation was found between the accessibility of the celluloses to a 30 A. molecule and their susceptibility to enzymatic attack, a further relationship was sought between reactivity and the surface area accessible to a molecule of a particular size. This would seem to be a more theoretically valid correlation to establish since the rate of a heterogeneous chemical reaction between molecules in solution and a solid is usually proportional to the available surface. The surface areas were calculated by incremental analysis of the accessibility curves in Figure 10, using the method discussed in the Experimental section and assuming that the surfaces in question are those associated with sheets... 

Enzymatic systems exhibit quite remarkable properties as far as the efficiency, smoothness and selectivity of the chemistry they can carry out is concerned. These are most probably related to a common feature of their structures, i.e., the existence of a reacting center, the prosthetic group, surrounded by protein chains. The latter offer a microenvironment able to modulate the reactivity of the prosthetic group without participating directly to the reaction. Such organized structures are correlatively expected to function with minimal entropy losses. The concept of supra-molecular chemistry, and electrochemistry, derives from attempts to imitate, even remotely, these structures and their functions. 

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