Junjie Wang

Bio: Junjie Wang is an academic researcher from Nanchang University. The author has contributed to research in topics: Quenching (fluorescence) & Hesperidin. The author has an hindex of 3, co-authored 3 publications receiving 175 citations.

Study on the interaction of hesperidin or icariin with lysozyme by fluorescence spectroscopy

Abstract: The interaction of hesperidin (HES) or icariin (ICA) and lysozyme (LYS) was studied by fluorescence spectroscopy in physiological buffer solution. It was observed that there was a strong fluorescence quenching effect of hesperidin or icariin on lysozyme. The quenching constants of the drugs with lysozyme were measured at different temperatures, and the quenching mechanism was suggested as dynamic quenching for HES-LYS system and both static and dynamic quenching for ICA-LYS system. The thermodynamic parameters of the interaction of hesperidin or icariin and lysozyme were measured according to the Van's Hoff equation: the enthalpy change (DeltaH) and the entropy change (DeltaS) of HES-LYS system and ICA-LYS system were calculated to be 20.29 kJ x mol(-1) and 146.28 J x mol(-1) x K(-1), and -3.47 kJ x mol(-1) and 81.16 J x mol(-1) x K(-1), respectively, which indicated that the interaction of hesperidin and lysozyme was driven mainly by hydrophobic force, whereas the interaction of icariin and lysozyme was driven mainly by electrostatic force. It was showed that the reaCtion processes of the two systems occurred spontaneously since Gibbs free energy change (DeltaG) values were negative. The binding distances of hesperidin and icariin from the lysozyme tryptophan residue were calculated to be 1.34 nm and 1.24 nm, respectively, based on the Forster's theory of non-radiation energy transfer. The results of synchronous fluorescence spectra showed that the binding of hesperidin or icariin to lysozyme induced conformational changes in lysozyme.

Flavones: From Biosynthesis to Health Benefits

Abstract: Flavones correspond to a flavonoid subgroup that is widely distributed in the plants, and which can be synthesized by different pathways, depending on whether they contain C- or O-glycosylation and hydroxylated B-ring. Flavones are emerging as very important specialized metabolites involved in plant signaling and defense, as well as key ingredients of the human diet, with significant health benefits. Here, we appraise flavone formation in plants, emphasizing the emerging theme that biosynthesis pathway determines flavone chemistry. Additionally, we briefly review the biological activities of flavones, both from the perspective of the functions that they play in biotic and abiotic plant interactions, as well as their roles as nutraceutical components of the human and animal diet.

Interaction between a potent corticosteroid drug – Dexamethasone with bovine serum albumin and human serum albumin: A fluorescence quenching and fourier transformation infrared spectroscopy study

Abstract: This study was designed to examine the interaction of dexamethasone (DEX) with bovine serum albumin (BSA) and human serum albumin (HSA) under physiological conditions with drug concentrations in the range of 2.5-20 microM and BSA/HSA was fixed at 5.0 microM. Spectroscopic analysis of the emission quenching at different temperatures revealed that the quenching mechanism of serum albumin by dexamethasone is static quenching mechanism. The binding sites number, n and binding constant, K were obtained at various temperatures. The distance r between dexamethasone and the protein was evaluated according to the theory of Foster energy transfer. The result of fluorescence spectra UV-vis absorption spectra and FT-IR spectra showed that the conformation of bovine serum albumin and human serum albumin has been changed in the presence of dexamethasone. The thermodynamic parameters, free energy change (DeltaG(0)), enthalpy change (DeltaH(0)) and entropy change (DeltaS(0)) for BSA-DEX and HSA-DEX were calculated according to van't Hoff equation and discussed.

Binding of serum albumins with bioactive substances – Nanoparticles to drugs

Abstract: The interactions of human and bovine serum albumins (HSA and BSA) with various drugs and nanomaterials receive great attention in the recent years owing to their significant impact in the biomedical field. Although there are various techniques available for studying such interactions, fluorescence spectroscopy is the most appealing one due to its high sensitivity and straightforwardness. Detailed information about the interactions of drugs and nanomaterials with serum can be deducted from a mass of information accumulated by the fluorescence quenching studies. The present review emphasizes the interaction of various nanomaterials, antibiotics, anticancer drugs, anti-inflammatory agents, dyes, flavonoids, and certain noxious materials with HSA and BSA. In particular, we focus on the interactions of serum albumin with nanomaterials having different size and stabilizing agents with various receptors. This review helps in understanding the structural features of drugs/nanomaterials crucial for not only their affinity for serum albumin but also their optimum pharmacological activities.