Novo Industri A/s

Novo Nordisk A/s

Jorgen Ilum Nielsen

Poul Borrevang

Henning Borge Petersen

Erling Guddal

Peter Faarup

A method is provided for controlling production of low molecular weight heparin (LMW-heparin) when depolymerizing heparin with heparinase in a reaction mixture in a reactor. Depolymerization to a desired average molecular weight is monitored by measuring an increase in UV-absorption (preferably at 230-235). When the absorption has reached a value for a desired molecular weight, the depolymerization is stopped or LMW-heparin having the desired molecular weight is continuously removed from the reaction mixture. In a preferred embodiment, the reaction mixture is subjected to ultrafiltration to produce a filtrate containing LMW-heparin, and a retentate which is recycled to the reactor. UV-absorption and refractive index of the filtrate are measured, and depolymerization is controlled in accordance with the measured absorption and refractive index to produce a filtrate containing a LMW-heparin of low polydispersity and predetermined molecular weight.

Process of using light absorption to control enzymatic depolymerization

An improvement in the conversion of penam and cephem compounds to secondary ammonium salts of phosphite amides thereof by reacting as follows: ##STR1## wherein --R, is the non-reacting balance of the penam or cephem compound and ##STR2## ARE NON-REACTING SUBSTITUENTS. Catalytic amounts of H--N&lt; or the hydrogenhalide thereof may be present in the reaction medium.

Process for the preparation of phosphorus derivatives of secondary

Novel penicillin and cephalosporin intermediates for the synthesis of 6-APA or 7-aminocephem compounds involving formation of a 6 or 7 phosphite amido compound and the conversion of such compound to a desired 6-APA or 7-aminocephem compound.

Growing community of inventors

Farum, Denmark

Jorgen Ilum Nielsen