The inhibition of bovine kidney hexosaminidase by N-acetylglucosamine-related 1,2,3-and 1,2,4-triazoles is in agreement with an 'anti'-protonation

The N-acetylglucosamine-related 1,2,4-triazole 14 and 1,2,3-triazole 16 hav e been prepared by N-acetylation of the known amines 19 and 20, and their K -i values determined against bovine kidney beta-N-acetylglucosaminidase, a mammalian hexosaminidase. The 1,2,3-triazole 16 (K-i = 4 mu M) is a markedl y weaker inhibitor than the isosteric azoles 13-15. The K-i value of the 1, 2,4-triazore 14 (0.034 mu M) is smaller than that of the tetrazole 13 (0.2 mu M), but larger than that of the imidazole 15 (0.0035 mu M), confirming t he correlation between inhibitory strength and basicity of the azole, as ex pected on the basis of an anti-protonation mechanism of mammalian hexosamin idases.