Parasite glycoconjugates .7. Synthesis of further substrate analogues of early intermediates in the biosynthetic pathway of glycosylphosphatidylinositol membrane anchors

Substrate analogues of 1D-6-O-(2-amino-2-deoxy-alpha-D-glucopyranosyl)-myo-inositol 1-[sn-2,3-bis(myristoyloxy)propyl phosphate], an early intermediate in the biosynthesis of glycosylphosphatidylinositol (GPI) membrane anchors, have been prepared for biological evaluation with the alpha-(1-->4)-D-mannosyltransferase of the protozoan parasite Trypanosoma brucei, The analogue alpha-D-GlcpNH(2)-(1-->6)-2-OMe-PI2 is a substrate for the protozoan alpha-(1-->4)-D-mannosyltransferase but not for the corresponding mammalian enzyme, whereas the analogues 3 and 4, in which the fatty-acid groups of the natural substrate are replaced by alkyl groups, are acceptable substrates for both the protozoan and mammalian enzymes.