Researchi And Application Of Molecularly Imprinted Technology In Purification And Separation For Epothilones

Epothilones (Epos) belong to the macrocyclic lactone class of compounds with highly activity of anti-tumor cells produced by Sorangium cellulosum, and they have great potential in drug development of anticancer drugs. Unfortunately, the inefficiency and high-cost in purification of epothilones seriously restricted the industrialization of epothilones. In this paper, we combined solid-phase extraction with molecular imprinting technology aim to study a new process which is efficiency and low-cost in researchi and purification of epothilones.Epothilones produced by solid state fermentation have characteristic of high purity, and after further purification the purity of epothilones can achieve 98% which can be used as molecular template for preparing molecularly imprinted polymers (MIPs).Bulk polymerization is a traditional method for preparing molecularly imprinted polymer. In this paper, with comparison and optimization for the functional, we synthesized the MIPs of Epos by thermal initiation polymerization. The optimal ratio was 1:4:20 (with the molar ratio), and the maximum absorption capacity of the MIPs was up to 128 mg g-1. Under the optimized condition, the resulted products were characterized by scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FT-IR), respectively. The adsorption kinetics and static adsorption of MIPs were evaluated by the Lagergren pseudo-second-order model and the Freundlich model. Meanwhile, we choose ivermectin and erythromycin as interferon to further demonstrate the competitive recognition and the selectivity of the MIPs. We applied the MIPs as a sorbent in the solid phase extraction (SPE) process, and the purity of epothilones were improved 43.21% than the origin.Surface molecular imprinting is a novel method for molecular imprinting technology, compared with the traditional polymerization method, the binding sites are formed on the surface of polymers, it is apt to adsorb and elute the template molecule. This study was carried out on epothilones molecularly imprinted polymers based on the surface of silica-gel which after silica silylation treatment. The resulted products were characterized by scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FT-IR), respectively. The binding properties of the polymers were evaluated by the Freundlich model and Scatchard model. The results showed that there are two kind of binding sites exist in epothilones molecularly imprinted polymers on the surface of silica-gel. For the higher affinity site, Qmax=26.76 mg/g, Kd=0.117 g/L, and for the lower affinity site, Qmax=64.98 mg/g, Kd=0.709 g/L.In conclusion, we applied molecular imprinting technology to the process of researchi and purification for epothilones, achieved a better results. Moreover, molecular imprinting technology is expected to become a new type of separation technology for epothilones.