盐酸拓扑替康及10-羟基喜树碱和转铁蛋白的相互作用

Study on the interaction between topotecan hydrochloride or 10-hydroxycamptothecin and transferrin bovine

The binding reactions between topotecan hydrochloride(THC) or 10-hydroxycamptothecin(HCPT) and transferrin bovine(Tf) are studied by fluorescence and UV-Vis absorption spectra.The research results indicate that the combination reaction of them is a single static quenching process,camptothecin derivatives strongly bound Tf with the molar ratio of 1∶1,the equilibrium constant(K0) at 25 oC are as follows,K0(THC)=2.38×105L·mol-1,K0(HCPT) =2.43×106 L·mol-1.The shortest binding distance(r)between donor(Tf) and acceptor(camptothecin derivatives) are obtained by Frster’s nonradiative energy transfer mechanism,rTHC =3.77nm,rHCPT =3.92.The enthalpy change(△H) and entropy change(△S) are calculated at 25 oC and 37 oC,the results indicate that hydrophobic interaction and the diple-diple force play a major role in the binding of camptothecin derivatives and Tf.The results of 1H NMR spectrum show that the active groups of HCPT interacting with Tf are 10-OH.

The binding reactions between topotecan hydrochloride （THC） or 10- hydroxycamptothecin （HCPT） and transferrin bovine （Tf） are studied by fluorescence and UV - Vis absorption spectra. The research results indicate that the combination reaction of them is a single static quench/ng process, camptothecin derivatives strongly bound Tf with the molar ratio of 1 ： 1, the equilibrium constant （K0） at 25℃ are as follows,K0（THC） =2.38 × 10^5L · mol^-1,K0（HCPT） =2.43 × 10^6L · mol^-1. The shortest binding distance（ r） between donor （T f） and acceptor （camptothecin derivatives） are obtained by Forster＇ s nonradiative energy transfer mechanism, rTHC = 3.77nm, rHCPT = 3.92. The enthalpy change （ △H） and entropy change （△S） are calculated at 25℃ and 37℃, the results indicate that hydrophobic interaction and the diple- diple force play a major role in the binding of camptothecin derivatives and Tf. The results of 1H NMR spectrum show that the active groups of HCPT interacting with Tf are 10 - OH.