POLY(OXY-1,2-ETHANEDIYL), .ALPHA.-HYDRO-.OMEGA.-METHOXY-, 12,13-DIETHER WITH N-(5-((3-(2,3-DIHYDROXYPROPOXY)PROPYL)AMINO)-1,5-DIOXOPENTYL)-L-.ALPHA.-GLUTAMYL-L-ALANYL-L-.ALPHA.-GLUTAMYL-L-.ALPHA.-ASPARTYL-L-LEUCYL-L-GLUTAMINYL-L-VALYLGLYCYL-L-GLUTAMINYL-