engleski

Pivaloylated Mannose Derivatives Catalysed by Esterases from Rabbit Serum

Acid or base catalysed intramolecular migrations of acyls in sugar molecules are well known, and possible mechanism of these transesterifications has been described1. Especially prone to migrations are acetyl groups which migrate spontaneously even in neutral organic solvents2. Intramolecular migrations caused by acid, base catalyze or organic solvents are not usually at pivaloylated carbohydrates. However, it was observed migration of pivaloyl group caused by enzymes present in some mammalian sera and it was previously described in a 14C-marked methyl-2, 6-di-O-pivaloyl-alpha-D-glucopyranoside3. In this work we described spontaneous pivaloyl group migrations in partially pivaloylated mannose, xylose and galactose series of sugars under influence of the reaction media and changeing temperature but without present of enzyme. All reactions were carried out in aqueous buffered solutions at the room and higher (60 C) temperature. 1. T. Horrobin, Ch. H. Tran, D. Crout, J. Chem. Soc., Perkin Trans I (1998) 1069-1080. 2. S. Tomić, Đ. Ljevaković, J. Tomašić, Tetrahedron 49 (1993) 10977-10986. 3. S. Tomić, Lj. Sesartić, J. Tomašić, Comp. Biochem. Physiol. 92B (1989) 681-684.

mannose derivatives; esterases; rabbit serum

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