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Structural Variations of N ‐Acetylneuraminic Acid, 7. Synthesis of the C‐7‐, C‐8‐, and C‐7,8‐Side Chain Epimers of 2‐Deoxy‐2,3‐didehydro‐ N ‐acetylneuraminic Acid and Their Behaviour Towards Sialidase from Vibrio cholerae
Author(s) -
Zbiral Erich,
Brandstetter Hannelore H.,
Christian Rudolf,
Schauere Roland
Publication year - 1987
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.198719870828
Subject(s) - chemistry , hydrolysis , epimer , trimethylsilyl , stereochemistry , side chain , trifluoromethanesulfonate , neuraminic acid , sialidase , cyclopropanation , n acetylneuraminic acid , medicinal chemistry , sialic acid , enzyme , organic chemistry , biochemistry , neuraminidase , catalysis , polymer
The peracetylated methyl ester derivatives of 7‐ epi ‐Neu5Ac ( 2a ), 8‐ epi ‐Neu5Ac ( 3a ), and 7,8‐bis‐ epi ‐Neu5Ac ( 4a ) were transformed by trimethylsilyl trifluoromethanesulfonate into the corresponding 2‐deoxy‐2,3‐didehydro derivatives 2b–4b . As minor products the 4,5‐oxazolino derivatives 5b and 6b are formed. Hydrolysis of 2b–4b yields the free acids 7‐ epi ‐Neu5Ac2ene ( 2c ), 8‐ epi ‐Neu5Ac2ene ( 3c ), and 7,8‐bis‐ epi ‐Neu5Ac2ene ( 4c ). These show significantly different inhibitory influences on the hydrolysis of 4‐methylumbelliferyl‐α‐Neu5Ac by Vibrio cholerae sialidase. This was the reason for establishing the conformation of 2c–4c and of the well‐known 2‐deoxy‐2,3‐didehydro‐ N ‐acetylneuraminic acid (Neu5Ac2ene) ( 1c ). A significant relationship between the characteristic profiles of the α‐side of 1c–4c and the influence on the enzyme reaction was found.