Syntheses of triglycosyl tetrapeptides and a hexaglycosyl tetrapeptide.
A stereo-controlled synthesis of the model compound for the phytoalexin elicitor-active glycoprotein is described. Glycosylation of the trisaccharide, 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl-(1-->6)-2,3,4-tri-O-acetyl- alpha-D-mannopyranosyl-(1-->6)-2,3,4-tri-O-acetyl-alpha-D-mannopyranosyl trichloroacetimidate (12), with N-(9-fluorenylmethoxycarbonyl)-L-seryl-L- proline benzyl ester (3) or N-(carbobenzoxy)-L-seryl-L-proline methyl ester (4) by use of BF3. OEt2 gave the triglycosyl-seryl-proline derivatives. The N- as well as C-terminus of these triglycosyl dipeptides could be deblocked selectively to give compounds 14 and 16, which are versatile intermediates for the completion of model compound synthesis of glycopeptide. Triglycosyl tetrapeptides (18, 21) and hexaglycosyl tetrapeptide (23) have been prepared by the convergent block synthesis.
Kyoritsu College of Pharmacy, Tokyo, Japan.
T
T
Takeda
T
T
Kanemitsu
N
N
Shimizu
Y
Y
Ogihara
M
M
Matsubara
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005449:Fluorenes / Q000378:metabolism; D006020:Glycopeptides / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009844:Oligosaccharides / Q000138:chemical synthesis*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D012717:Sesquiterpenes; D013729:Terpenes; D000094162:Phytoalexins
D000596:Amino Acids; D005449:Fluorenes; D006020:Glycopeptides; C016456:N(alpha)-fluorenylmethyloxycarbonylamino acids; D009844:Oligosaccharides; D010455:Peptides; D010936:Plant Extracts; D012717:Sesquiterpenes; D013729:Terpenes; D000094162:Phytoalexins