title: Competitive interactions of anti-carcinogens with serum albumin: a spectroscopic study of bendamustine and dexamethasone with the aid of chemometrics.
abstract: Interactions between the anti-carcinogens, bendamustine (BDM) and dexamethasone (DXM), with bovine serum albumin (BSA) were investigated with the use of fluorescence and UV-vis spectroscopies under pseudo-physiological conditions (Tris-HCl buffer, pH 7.4). The static mechanism was responsible for the fluorescence quenching during the interactions; the binding formation constant of the BSA-BDM complex and the binding number were 5.14×10(5)Lmol(-1) and 1.0, respectively. Spectroscopic studies for the formation of BDM-BSA complex were interpreted with the use of multivariate curve resolution - alternating least squares (MCR-ALS), which supported the complex formation. The BSA samples treated with site markers (warfarin - site I and ibuprofen - site II) were reacted separately with BDM and DXM; while both anti-carcinogens bound to site I, the binding constants suggested that DXM formed a more stable complex. Relative concentration profiles and the fluorescence spectra associated with BDM, DXM and BSA, were recovered simultaneously from the full fluorescence excitation-emission data with the use of the parallel factor analysis (PARAFAC) method. The results confirmed that on addition of DXM to the BDM-BSA complex, the BDM was replaced and the DXM-BSA complex formed; free BDM was released. This finding may have consequences for the transport of these drugs during any anti-cancer treatment.
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; Department of Chemistry, Nanchang University, Nanchang 330031, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Nanchang University, Nanchang 330031, China.
authors.forename: Ruirui
authors.initials: R
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; Department of Chemistry, Nanchang University, Nanchang 330031, China. Electronic address: ynni@ncu.edu.cn.
authors.forename: Yongnian
authors.initials: Y
authors.lastname: Ni
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane 4001, Australia. Electronic address: s.kokot@qut.edu.au.
authors.forename: Serge
authors.initials: S
authors.lastname: Kokot
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000737:chemistry / Q000378:metabolism*; D000069461:Bendamustine Hydrochloride; D002417:Cattle; D003907:Dexamethasone / Q000737:chemistry / Q000378:metabolism*; D016018:Least-Squares Analysis; D015999:Multivariate Analysis; D009588:Nitrogen Mustard Compounds / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
chemical_list: D016588:Anticarcinogenic Agents; D009588:Nitrogen Mustard Compounds; D012710:Serum Albumin, Bovine; D003907:Dexamethasone; D000069461:Bendamustine Hydrochloride
keywords: Anti-carcinogens; BSA; Bendamustine and dexamethasone; Fluorescence spectroscopy; Multivariate curve resolution – alternating least squares; Parallel factor analysis