Separation of phenyl acetic acid and 6-aminopenicillanic acid applying aqueous two-phase systems based on copolymers and salts

6-Aminopenicillanic acid (6-APA) is used for synthesis of semisynthetic antibiotics. Polymer-salt aqueous two-phase systems (ATPSs) were applied for separation of 6-APA and phenyl acetic acid (PAA), as the products of hydrolyzation reaction of Penicillin G/Penicillin V. The binodal curves of ATPS composed of a copolymer (reverse Pluronic 10R5, Pluronic L35 and PEG-ran-PPG) and a salt (Tri-sodium citrate, tri-potassium citrate, di-potassium phosphate, sodium sulphate and magnesium sulphate) were obtained. The results show that, at a fixed PPG/PEG ratio, block copolymers have larger two-phase region compared with random copolymer. After screening on the partition coefficient of PAA and 6-APA separately, Na2SO4 was selected for studying the effect of the copolymer structure and the composition of salt and copolymer on partitioning, considering higher selectivity of PAA and 6-APA. 10R5-Na2SO4 ATPS was selected as the most appropriate system for separation of 6-APA and PAA. This system was used for separation of mixture of 6-APA and PAA. The results show that selectivity was approximate to 53 and smaller in a system, containing a mixture of 6-APA and PAA. This observation can be justified by the interaction between 6-APA and PAA. Molecular interaction between these two molecules were investigated by the Flory-Huggins interaction parameter.

Automated summary

The study utilized polymer-salt aqueous two-phase systems (ATPSs) for the separation of 6-aminopenicillanic acid (6-APA) and phenyl acetic acid (PAA), with Na2SO4 selected as the most appropriate salt and 10R5-Na2SO4 ATPS chosen as the optimal separation system. Molecular interactions between these two molecules were investigated, and the results showed a selectivity of approximately 53 with smaller selectivity observed in a mixture system of 6-APA and PAA.