摘要:
The invention relates to a new method of preparing oligomannuronic diacids, important bioactives. The method utilizes oligomannuronic acids as starting materials and the target substances are obtained by acid degradation and active hypobromous acid oxidation steps. The method of preparing oligomannuronic diacids according to the invention employs moderate reaction conditions, has few side reactions, does not need further purification, achieves a yield of more than 90%, or even more than 95%, and is suitable for production with an on-line continuous reactor device, with reaction processes easy to implement automatic control.
摘要:
In a composition comprising a therapeutic agent and a compound which is a trisaccharide or higher polysaccharide, that compound has the formula X[-Y-Z]n wherein X and Z are each saccharide molecules in which none, some or all OH groups are derivatised; Y is an ester linkage to an/the exocyclic C atom in X, i.e. the 6-C atom in a hexose or the 5-C atom in a pentose; and n is an integer.
摘要:
The invention concerns pharmaceutical compositions containing as active principle an oligosaccharide or formula (I) or a mixture of said oligosaccharides, novel oligosaccharides of formula (I), mixtures thereof and methods for preparing them.
摘要:
Primary alcohols, especially in carbohydrates, can be selectively oxidised to aldehydes and carboxylic acids in a low-halogen process by using a peracid in the presence of a catalytic amount of a di-tertiary-alkyl nitroxyl (TEMPO) and a catalytic amount of halide. The halide is preferably bromide and the process can be carried out at nearly neutral to moderately alkaline pH (5-11). The peracid can be produced or regenerated by means of hydrogen peroxide or oxygen. The process is advantageous for producing uronic acids and for introducing aldehyde groups which are suitable for crosslinking and derivatisation.