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Objective To investigate the affinity and interaction of a folate receptor targeted rhapontion(RHA)conjugate (FRHA)with human serum albumins(HSA). Method The interaction between FRHA and HSA under physiological conditions was investigated by fluorescence spectroscopy,UV-visual(vis)spectroscopy and circular dichroism(CD)spectroscopy. Great attempts were made to investigate their interaction mechanism regarding the quenching mechanism,the specific binding site,the type of inter-action force,and the effect of FRHA on the micro-environmental and conformational changes in HSA molecules. Results The forma-tion of the complex of FRHA-HSA would lead to fluorescence quenching. The corresponding values of Ka were 1.4322 × 105,1.1793 × 105,0.9334 × 105 and 0.7896 × 105 L/mol when the temperature were 298,302,306,and 310 K,respectively. The enthalpy change (ΔH)and entropy change(ΔS)were calculated to be-38.772 kJ/mol and-31.39 J/(mol·K),indicating that van der Waals force and hydrogen bonds played major roles in stabilizing the complex. Conclusion The interaction process of the formation of FRHA-HSA is spontaneous. The negative values of enthalpy change(ΔH)and entropy change(ΔS)indicate that van der Waals force and hydrogen bonds play major roles in stabilizing the complex. The conformational investigation reveals theα-helical structure is decreased and the microenvironment of HSA is changed upon the addition of FRHA. The fluorescence quenching of HSA caused by FRHA is static quenching. Furthermore,the results of site marker competitive experiment suggest that FRHA binds to the sub-domainⅡA of HSA.
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Because of the high morbidity and mortality rate,cardio-cerebrovascular diseases,including cerebral embolism, cerebral hemorrhage,cerebral vasospasm and myocardial infarction,have become main diseases threatening human health. Tradition-al chinese medicine(TCM)holds that the basic pathogenesis is Qi imbalances,which could be improved by benefiting Qi and promot-ing blood circulation. The compatibility of Radix astragali and Radix salviae miltiorrhiae are particularly suitable for treating the car-dio-cerebrovascular system diseases by improving Qi deficiency and blood stasis. This paper focuses on the application of Radix astrag-ali,Radix s. miltiorrhiae and their compatibility for treating the cardio-cerebrovascular system diseases. Moreover,our research would offer valuable references for the development of new drugs related to the treatment of cardio-cerebrovascular system diseases.
RESUMO
Notwithstanding the noteworthy advances in its treatment,malignant tumor remains one of the main diseases threat?ening human health. Therefore,it is urgent to search and develop novel anticancer drugs with high curative effect and less side effect. In this review,we focus on summarizing the physio-chemical properties,preparation processes,anti-tumor activity mechanisms,clini?cal effects,side effects,and main isomers,especially the research progress of temsirolimus,with the hope to provide some reference for the further research.