Some properties of synthetic fucopyranosylserines and -threonines.
alpha Fuc-Ser, alpha Fuc-Thr, beta Fuc-Ser, and beta Fuc-Thr were synthesized stereoselectively in good yields, and their properties were investigated. beta-Fucosylserine (and -threonine) was synthesized by Koenigs-Knorr reaction of per-O-acetylfucopyranosyl bromide with N-carbobenzoxy-L-serine (and -threonine) benzyl ester using mercuric cyanide, followed by hydrogenolysis and deacetylation. alpha-Fucosylserine (and -threonine) was synthesized by the halide-ion catalyzed reaction of per-O-benzylfucopyranosyl bromide with the serine (and threonine) derivative described above, followed by hydrogenolysis. These substances each gave a single peak on an amino acid analyzer. The anomeric configurations of these compounds were determined by 1H-NMR spectroscopy, optical rotation measurement and enzymatic degradations of these compounds. On acid hydrolysis, alpha Fuc-Ser and alpha Fuc-Thr were more rapidly hydrolyzed than the corresponding beta-series compounds. Under mild alkaline conditions in the presence of sodium borohydride, per-protected beta Fuc-Thr released about 50% of fucose but free beta Fuc-Thr did not However, free alpha Fuc-Thr and beta Fuc-Thr were cleaved to give acetylated fucose during acetylation with acetic anhydride-pyridine. alpha-L-Fucosidases, which were purified from abalone and rabbit livers by affinity chromatography, acted very well on alpha Fuc-Ser and alpha Fuc-Thr, but not on the beta-series compounds.
D005643:Fucose / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D007202:Indicators and Reagents; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D012694:Serine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D013055:Spectrophotometry, Infrared; D013237:Stereoisomerism; D013912:Threonine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D005644:alpha-L-Fucosidase / Q000378:metabolism
D007202:Indicators and Reagents; D005643:Fucose; D013912:Threonine; D012694:Serine; D005644:alpha-L-Fucosidase