Starting from sucrose, 2,3,1' ,3',4',6'-hexa-O-benzoyl-6-deoxy-6-iodosucrose*
(1) was synthesized.
Reaction
of 1 with sulfuryl chloride in pyridine gave 2,3,1 ',3',4',6'-hexa-O-benzoyl-4-chloro-4,6-dideoxy-6-iodogalactosucrose (2). Compound 2 was treated with tributyltin hydride in toluene in the presence of a radical initiator, cr,cu-azobis(isobutanonitrile) (AIBN), to remove iodine and chlorine groups and give hexa-0-benzoyl-4,6-dideoxysucrose.
Benzoyl groups were removed by sodium methoxide in methanol to give 4,6-dideoxysucrose.
Sucrose was modified at carbon atom 3, carbon atom 4, or carbon atoms 4 and 6, and these analogs wcrc tested as inhibitors of the D-glUCanSuCraSeS (D-glucosyltransferases)
of Streptococcus mutans 6715 and Leuconostoc mesenteroides B-512F. Sucrose analogs used in this study are 4-deoxysucrose and 4-chloro-4deoxygalactosucrose with S. mutans 6715 D-glucansucrases (GTF-S and GTF-I), and 3-deoxysucrose, 4-deoxysucrose, 4-chloro-4-deoxygalactosucrose, 6-deoxysucrose, and 4,6-didcoxysucrosc with L. mesenteroides B-512F D-glucansucrase. The data indicate that 3-deoxysucrose, 4-deoxysucrose, and 4-chloro-4deoxygalactosucrose are weak noncompetitive inhibitors for B-512F dextransucrase, with K, values of 530, 201, and 202mM respectively. For the same enzyme, 6-deoxysucrose was a strong competitive inhibitor, with Ki of 1.6OmM, and 4,6-dideoxysucrose was a good competitive inhibitor, with Ki of 20.3mM. 4-Deoxysucrose was a weak noncompetitive inhibitor for both GTF-I and GTF-S, with Ki values of 672 and 608mM, respectively. 4-Chloro-4-deoxygalactosucrose was also a weak noncompetitive inhibitor for GTF-I and GTF-S with Ki values of 391 and 308mM, respectively. The inhibition data indicate that replacement of the 6-hydroxyl group