SYNTHESIS OF HYL)-L-GLUTAMINYL]-N5-(2-HYDROXYETHYL)-L-GLUTAMINE

The synthetic, water-soluble polypeptide, poly[N5-(2-hydroxyethyl)-L-g lutamine] (PHEG), was proposed as a suitable polymer for biomedical ap plications1,2. Its biodegradability was demonstrated both in vitro and in vivo3,4. Ultimate degradation fragments resulting from the degrada tion of PHEG by endopeptidades, e.g. papain, are oligomers (down to te tramers) of N5-(2-hydroxyethyl)-L-glutamine (HEG), which can be furthe r degraded to dimeric and monomeric HEG by exopeptidases5. For in vivo studies related to the toxicology and metabolic disposition of these low-molecular-weight fragments of PHEG degradation as well as for an a ccurate calibration of analytical methods used, such as size exclusion chromatography (SEC), the standards, monomeric and dimeric HEG, are o f crucial importance. This communication reports on the synthesis of d imer of HEG, hyl)-L-glutaminyl]-N5-(2-hydroxyethyl)-L-glutamine (Schem e 1). Its applicability as a calibration standard is demonstrated in F ig. 1 showing its elution curve together with the curves of PHEG and H EG monomer.