Organisms and Nicotinic Acid Derivatives

When examined by following oxygen uptake the effects of different derivatives of nicotinic acid were not straightforward. Though nicotinamide was more active than nicotinic acid, cozymase was less active than nicotinamide. This observation, initially based on a comparison of nicotinamide with a specimen of cozymase estimated to be 40% pure, was confirmed by showing the activity of such a preparation, and also one of coenzyme II, to be increased on hydrolysis by autoclaving with 0.1 JV sulfuric acid. Conclusions drawn from these findings are discussed below. 

An analogous observation was made in the course of examining the effects of similar preparations on the respiration of Proteus vulgaris (102). 

A further point indicates the need to follow coenzyme synthesis in the 

Inactivation of Nicotinic Acid Derivatives by Proteus vulgaris 

A different experimental arrangement permitted the speed and magnitude of response to added nicotinic acid to be more easily observed. Oxygen uptake was determined manomctrically with glucose as substrate again, deficiencies were observed in 

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