Transesterification of PHA to Oligomers Covalently Bonded with (Bio)Active Compounds Containing Either Carboxyl or Hydroxyl Functionalities

摘要

This manuscript presents the synthesis and structural characterisation of novel biodegradableudpolymeric controlled-release systems of pesticides with potentially higher resistance toudweather conditions in comparison to conventional forms of pesticides. Two methods for theudpreparation of pesticide-oligomer conjugates using the transesterification reaction were developed.udThe first method of obtaining conjugates, which consist of bioactive compoundsudwith the carboxyl group and polyhydroxyalkanoates (PHAs) oligomers, is "one-pot" transesterification.udIn the second method, conjugates of bioactive compounds with hydroxyl groupudand polyhydroxyalkanoates oligomers were obtained in two-step method, through cyclicudpoly(3-hydroxybutyrate) oligomers. The obtained pesticide-PHA conjugates were comprehensivelyudcharacterised using GPC, 1H NMR and mass spectrometry techniques. Theudstructural characterisation of the obtained products at the molecular level with the aid ofudmass spectrometry confirmed that both of the synthetic strategies employed led to the formationudof conjugates in which selected pesticides were covalently bonded to PHA oligomersudvia a hydrolysable ester bond.