| 摘要 |
<p>Prepn. of 6-mercapto-nicotinic acid (I) comprises (i) heating at least a stoichiometric mixt. of 6-chloronicotinic acid (I) and an alkali metal sulphide at above 120 degrees C; (ii) dissolving the ppte. in weak aq. alkali soln. and (iii) precipitating (I) by adding mineral acid. The alkali metal sulphide is e.g. Na2S or Na2S2. (I) can be oxidised to 6,6'-dithiodinicotinic acid, which is used in biochemical analysis to determine the total glutathione content of human blood, or to detech thiols. Similarly 6,6'-dithiodinicotinic acid can be used to determine the choline esterase activity in serum. The reagent is esp. for use in automatic analyses.</p> |
