Process for the preparation of highly O-sulfated, epimerized derivatives of K5 polysacchride and intermediates therein

摘要

A new method is described for the oversulfation of epiK5-N-sulfate to obtain an epiK5-amine-O-oversulfate with very high sulfation degree which, by subsequent N-sulfation, provides new epiK5-N,O-oversulfate-derivatives with a sulfation degree of at least 4, basically free of activity on the coagulation parameters and useful in the cosmetic or pharmaceutical field. Also described are new low molecular weight epiK5-N-sulfates useful as intermediates in the preparation of the corresponding LMW-epiK5-N,O-oversulfate-derivatives.

主权项

1. A process for the preparation of epiK5-amine-O-oversulfate-derivatives having a glucosamine 3-O-sulfate content of at least 40%, which comprises
(a) treating an epiK5-N-sulfate-derivative, in acidic form, with a tertiary or quaternary organic base, letting the reaction mixture to stand for a time period of 30-60 minutes at a pH of approximately 7 and isolating the corresponding organic base salt of said epiK5-N-sulfate; and (b) treating said tertiary amine or quaternary ammonium salt of said epiK5-N-sulfate-derivative with an O-sulfation agent in the conditions of 0-oversulfation and isolating the epiK5-amine-O-oversulfate-derivative.