Kinetical studies were performed on the condensation reactions of 2‐aminopropane and two carboxylated polymers (poly(acrylic acid) and xanthan) in the presence of dicyclohexylcarbodiimide as an activator. The rate constants of the second order reactions were determined and discussed.

In the present paper the immobilization of invertase and amyloglucosidase on Biozan R with dicyclohexylcarbodiimide as a catalyst is studied. The influence of some factors on the coupling reaction (duration, enzyme/support and catalyst/support ratios) as well on the acitvity of the coupled enzyme in followed. For both systems under study the value of the Michaelis-Menten constant is higher for the coupled enzyme than for the free one.

Different enzymes (&-amylase, amyloglucosidase) and drugs (procaine, 7-aminocephalosporanic acid, sulphathiazole, ampicillin, chloramphenieol) have been immobilized on cellulose derivatives and Biozan R through covalent bonds to obtain biologically active compounds. Coupling reaction of drugs was achieved by using dieyclohexyl carbodiimide as activating agent. Optimum parameters (temperature, tirnc, drug Concentration, matrix amount, activator concentration) were found. A n Polymeren fixierte Enzyme und Arzneistoffe. Synthese und Anwendungen in der TherapeutikVerschiedene Enzyme (a-Amylase, Amyloglucosidase) und Arzneistoffe (Procain, 7-Amino-Cephalosporansaure, Sulfatiasol, Ampicillin, Chloramphenicol) wurden covalent an Cellulosederivate und Biozan R gebunden, um biologisch aktive Verhindungen zu erhalten. Die Kopplungsreaktion wurde unter Verwendung von Dieyclohexylcarbodiimid als Aktivator durchgefuhrtf. Die optimalen Werte der Reaktionsparameter (Temperatur, Zeit, Konzentration der Arzneistoffe, Tragermenge, Aktivatorkonzentration) wurden bestimmt. f % 3~. w~~ u nezupcmsenclzace seqecmsa, aa@~~cuposu~naze Ha nonuwepax. C u~m e a u npuweHeuue 8 mepaneemuze P a a n m~b~e ~H~A M L I (a-a~unaaa, a~~n o r n y~o 3 n g a 3 a ) H neKapcTseHHHe BelqecTBa (npoKam, 7 -a~~~o q e @ a n o c n o -PaHOBaR KHCJIOTa, CyJIbl#aTHa30Jl, aMIIHQHJlHH, XJIOpaMl#t?HHKOJI) ~LIJIH 3al#HKCHpOBaHLI H a IIPOH3BOAHLlX qeJIJII0-J703LI M BElO3aHe P KOBaneHTHLIMH CBRBBMH AJIR IIOJIJ'YeHHR 6~n o r~s e c~~ aKTHBHbIX COeAMHeHEl&. PeaKqMR HMMO-6 n n~3 a q~n JIeKapCTBeHHLIX BeUeCTB peaJIH3OBaHa C IIClIOJIb30BaHMeM

INTRODUCTIONThe drug retardation on synthetic and natural macromolecular supports is continuously being developed due to the multiple advantages of these new products in chemotherapy [1]. Numerous drugs have been coupled by either covalent or ionic bonds on biocompatible polymers [12][13]. The nalidixic acid (NxAc) is an antibacterial agent active against gram negative species, especially in infections of the genitourinary tract, as well as a preventive of pre-and post-operative gynecological infections. Due to the high rate of elimination the administrated doses are of 4 g/day. This shortcoming may be overcome by the conjugation of NxAc on xanthan. EXPERIMENTALThe esterification reaction of nalidixic acid (1-ethyl-7-methylnaftiridin-4-keto-3-carboxylic acid) with xanthan was carried out in DMSO with dicyclohexylcarbodiimide (DCC) as an activator.The necessary amounts of DMSO and xanthan (Table 1) were introduced into a flask and stirred for 2 h to swell the xanthan particles. The NxAc and DC were added in a 1/1.1 mole ratio. The coupling proceeded at the room temperature, under good stirring. The reaction mixture was precipitated in 250 ml MeOH and the precipitate (the ester of NxAc with xanthan) washed with 250 ml MeOH and dried under

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