Co-reporter:Yan-Yue Lou, Kai-Li Zhou, Jie-Hua Shi, Dong-Qi Pan
Journal of Photochemistry and Photobiology B: Biology 2017 Volume 173(Volume 173) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.jphotobiol.2017.06.037
•The fluorescence of BSA quenched by boscalid due to forming stable boscalid-BSA complex•Boscalid bound on the subdomain IIIA (site II) of BSA•The interaction forces were mainly van der Waal's forces and hydrogen bonding interaction.•There was a slight change in the secondary structure of BSA due to binding boscalid.•The flexibility of boscalid played a critial role in the binding process.Boscalid, a carboxamide fungicide, is used in the treatment of grey mould and powdery mildew, widely applied to a variety of crops and fruits such as rice, wheat, grapes and pears. It will become a potential risk for health due to its widely application and residue in crops and fruits. In this study, the binding interaction between boscalid and bovine serum albumin (BSA) was characterized using steady-state fluorescence spectroscopy, ultraviolet spectroscopy (UV), synchronous fluorescence spectroscopy, 3D fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and molecular docking to ascertain the store, transport and distribution of boscalid in vivo. The experimental results indicated that the fluorescence of BSA was quenched due to the forming the static boscalid–BSA complex with the binding constant of 4.57 × 103 M− 1 at 298 K and boscalid bound on the subdomain III A (site II) of BSA through van der Waals force and hydrogen bonding interaction. The binding process of boscalid with BSA was spontaneous and enthalpy-driven process based on ΔG0 < 0 and | ΔH0 | > T | ΔS0 | over the studied temperature range. Meanwhile, the obvious change in the conformation of boscalid was observed while the slight change in the conformation of BSA when binding boscalid to the BSA, implying that the flexibility of boscalid contributes to increasing the stability of the boscalid–BSA complex.Download high-res image (221KB)Download full-size image
Co-reporter:Qi Wang, Chuan-ren Huang, Min Jiang, Ying-yao Zhu, Jing Wang, Jun Chen, Jie-hua Shi
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2016 Volume 156() pp:155-163
Publication Date(Web):5 March 2016
DOI:10.1016/j.saa.2015.12.003
•Atorvastatin binds to the subdomain IIA (site I) of BSA and forms 1:1 complex with it.•The fluorescence quenching of BSA induced by atorvastatin is a combined dynamic and static quenching.•Atorvastatin binding results in a decrease in α-helix content of BSA.•The main interaction forces are van der Waals and hydrogen bonding interactions.•The flexibility of atorvastatin plays an important role in increasing the atorvastatin–BSA stability.The interaction of atorvastatin with bovine serum albumin (BSA) was investigated using multi-spectroscopic methods and molecular docking technique for providing important insight into further elucidating the store and transport process of atorvastatin in the body and the mechanism of action and pharmacokinetics. The experimental results revealed that the fluorescence quenching mechanism of BSA induced atorvastatin was a combined dynamic and static quenching. The binding constant and number of binding site of atorvastatin with BSA under simulated physiological conditions (pH = 7.4) were 1.41 × 105 M− 1 and about 1 at 310 K, respectively. The values of the enthalpic change (ΔH0), entropic change (ΔS0) and Gibbs free energy (ΔG0) in the binding process of atorvastatin with BSA at 310 K were negative, suggesting that the binding process of atorvastatin and BSA was spontaneous and the main interaction forces were van der Waals force and hydrogen bonding interaction. Moreover, atorvastatin was bound into the subdomain IIA (site I) of BSA, resulting in a slight change of the conformation of BSA.It was confirmed that atorvastatin binds to site I of BSA via van der Waals and hydrogen bonding interactions and forms 1:1 complex with it through spectroscopic methods and molecular docking.
Co-reporter:Jie-hua Shi, Dong-qi Pan, Min Jiang, Ting-Ting Liu, Qi Wang
Journal of Photochemistry and Photobiology B: Biology 2016 Volume 164() pp:103-111
Publication Date(Web):November 2016
DOI:10.1016/j.jphotobiol.2016.09.025
•The fluorescence of BSA quenched by ramipril due to forming stable ramipril-BSA complex.•Ramipril located on the subdomain IIA (site I) of BSA.•The main interaction forces were both van der Waal's forces and hydrogen bonding interaction.•There was a slight change in the secondary structure of BSA due to binding ramipril.The binding interaction between a typical angiotensin-converting enzyme inhibitor (ACEI), ramipril, and a transport protein, bovine serum albumin (BSA), was studied in vitro using UV–vis absorption spectroscopy, steady-state fluorescence spectroscopic titration, synchronous fluorescence spectroscopy, three dimensional fluorescence spectroscopy, circular dichroism and molecular docking under the imitated physiological conditions (pH = 7.4). The experimental results suggested that the intrinsic fluorescence of BSA was quenched by ramipril thought a static quenching mechanism, indicating that the stable ramipril–BSA complex was formed by the intermolecular interaction. The number of binding sites (n) and binding constant of ramipril–BSA complex were about 1 and 3.50 × 104 M− 1 at 298 K, respectively, suggesting that there was stronger binding interaction of ramipril with BSA. The thermodynamic parameters together with molecular docking study revealed that both van der Waal's forces and hydrogen bonding interaction dominated the formation of the ramipril–BSA complex and the binding interaction of BSA with ramipril is enthalpy-driven processes due to | ΔH°| > | TΔS°| and ΔG° < 0. The spatial distance between ramipril and BSA was calculated to be 3.56 nm based on Förster's non-radiative energy transfer theory. The results of the competitive displacement experiments and molecular docking confirmed that ramipril inserted into the subdomain IIA (site I) of BSA, resulting in a slight change in the conformation of BSA but BSA still retained its secondary structure α-helicity.
Co-reporter:Min Jiang;Chuan-ren Huang;Qi Wang;Ying-yao Zhu;Jing Wang;Jun Chen
Luminescence 2016 Volume 31( Issue 2) pp:468-477
Publication Date(Web):
DOI:10.1002/bio.2984
Abstract
To further understand the mode of action and pharmacokinetics of lisinopril, the binding interaction of lisinopril with bovine serum albumin (BSA) under imitated physiological conditions (pH 7.4) was investigated using fluorescence emission spectroscopy, synchronous fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD) and molecular docking methods. The results showed that the fluorescence quenching of BSA near 338 nm resulted from the formation of a lisinopril–BSA complex. The number of binding sites (n) for lisinopril binding on subdomain IIIA (site II) of BSA and the binding constant were ~ 1 and 2.04 × 104 M–1, respectively, at 310 K. The binding of lisinopril to BSA induced a slight change in the conformation of BSA, which retained its α-helical structure. However, the binding of lisinopril with BSA was spontaneous and the main interaction forces involved were van der Waal's force and hydrogen bonding interaction as shown by the negative values of ΔG0, ΔH0 and ΔS0 for the binding of lisinopril with BSA. It was concluded from the molecular docking results that the flexibility of lisinopril also played an important role in increasing the stability of the lisinopril–BSA complex. Copyright © 2015 John Wiley & Sons, Ltd.
Co-reporter:Jie-hua Shi, Dong-qi Pan, Xiou-xiou Wang, Ting-Ting Liu, Min Jiang, Qi Wang
Journal of Photochemistry and Photobiology B: Biology 2016 Volume 162() pp:14-23
Publication Date(Web):September 2016
DOI:10.1016/j.jphotobiol.2016.06.025
•The intrinsic fluorescence of BSA quenched by AMT due to forming stable AMT-BSA.•AMT located on the interface between sub-domain IIA and IIB of BSA.•The main interaction forces were van der Waals.•There was a slight change of the secondary structure of BSA due to binding AMT.Artemether (AMT), a peroxide sesquiterpenoides, has been widely used as an antimalarial for the treatment of multiple drug-resistant strains of plasmodium falciparum malaria. In this work, the binding interaction of AMT with bovine serum albumin (BSA) under the imitated physiological conditions (pH 7.4) was investigated by UV spectroscopy, fluorescence emission spectroscopy, synchronous fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR), circular dichroism (CD), three-dimensional fluorescence spectroscopy and molecular docking methods. The experimental results indicated that there was a change in UV absorption of BSA along with a slight red shift of absorption wavelength, indicating that the interaction of AMT with BSA occurred. The intrinsic fluorescence of BSA was quenched by AMT due to the formation of AMT–BSA complex. The number of binding sites (n) and binding constant of AMT–BSA complex were about 1 and 2.63 × 103 M− 1 at 298 K, respectively, suggesting that there was stronger binding interaction of AMT with BSA. Based on the analysis of the signs and magnitudes of the free energy change (ΔG0), enthalpic change (ΔH0) and entropic change (ΔS0) in the binding process, it can be concluded that the binding of AMT with BSA was enthalpy-driven process due to | ΔH°| > | TΔS°|. The results of experiment and molecular docking confirmed the main interaction forces between AMT and BSA were van der Waals force. And, there was a slight change in the BSA conformation after binding AMT but BSA still retains its secondary structure α-helicity. However, it had been confirmed that AMT binds on the interface between sub-domain IIA and IIB of BSA.It has been confirmed that AMT interacts with BSA via van der Waals through spectroscopic methods (such as UV spectroscopy, fluorescence emission spectroscopy, synchronous fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR), circular dichroism (CD), three-dimensional fluorescence spectroscopy) and molecular docking. It is important to note that AMT located on the interface between sub-domain IIA and IIB of BSA.
Co-reporter:Jie-hua Shi;Ying-yao Zhu;Jing Wang;Jun Chen
Luminescence 2015 Volume 30( Issue 1) pp:44-52
Publication Date(Web):
DOI:10.1002/bio.2688
Abstract
The binding interactions between megestrol acetate (MA) and bovine serum albumin (BSA) under simulated physiological conditions (pH 7.4) were investigated by fluorescence spectroscopy, circular dichroism and molecular modeling. The results revealed that the intrinsic fluorescence of BSA was quenched by MA due to formation of the MA–BSA complex, which was rationalized in terms of a static quenching procedure. The binding constant (Kb) and number of binding sites (n) for MA binding to BSA were 2.8 × 105 L/mol at 310 K and about 1 respectively. However, the binding of MA with BSA was a spontaneous process due to the negative ∆G0 in the binding process. The enthalpy change (∆H0) and entropy change (∆S0) were – 124.0 kJ/mol and –295.6 J/mol per K, respectively, indicating that the major interaction forces in the binding process of MA with BSA were van der Waals forces and hydrogen bonding. Based on the results of spectroscopic and molecular docking experiments, it can be deduced that MA inserts into the hydrophobic pocket located in subdomain IIIA (site II) of BSA. The binding of MA to BSA leads to a slight change in conformation of BSA but the BSA retained its secondary structure, while conformation of the MA has significant change after forming MA–BSA complex, suggesting that flexibility of the MA molecule supports the binding interaction of BSA with MA. Copyright © 2014 John Wiley & Sons, Ltd.
Co-reporter:Jie-Hua Shi, Jun Chen, Jing Wang, Ying-Yao Zhu
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2015 Volume 136(Part B) pp:443-450
Publication Date(Web):5 February 2015
DOI:10.1016/j.saa.2014.09.056
•Sorafenib binds to DNA via minor groove binding and forms 1:1 complex with it.•The main interaction forces were van der Waals and hydrogen bonding interactions.•There was slight change of the secondary structure of DNA due to binding sorafenib.•The flexibility of sorafenib plays an important role in increasing the sorafenib–DNA stability.The binding interaction of sorafenib with calf thymus DNA (ct-DNA) was studied using UV–vis absorption spectroscopy, fluorescence emission spectroscopy, circular dichroism (CD), viscosity measurement and molecular docking methods. The experimental results revealed that there was obvious binding interaction between sorafenib and ct-DNA. The binding constant (Kb) of sorafenib with ct-DNA was 5.6 × 103 M–1 at 298 K. The enthalpy and entropy changes (ΔH0 and ΔS0) in the binding process of sorafenib with ct-DNA were –27.66 KJ mol–1 and –21.02 J mol–1 K–1, respectively, indicating that the main binding interaction forces were van der Waals force and hydrogen bonding. The docking results suggested that sorafenib preferred to bind on the minor groove of A-T rich DNA and the binding site of sorafenib was 4 base pairs long. The conformation change of sorafenib in the sorafenib–DNA complex was obviously observed and the change was close relation with the structure of DNA, implying that the flexibility of sorafenib molecule played an important role in the formation of the stable sorafenib–ct-DNA complex.Graphical abstractIt was confirmed that sorafenib interacts with ct-DNA via minor groove binding mode through spectroscopic methods (such as UV–vis absorption spectroscopy, and fluorescence emission spectroscopy) and molecular doching.
Co-reporter:C.-B. Chen;J. Chen;J. Wang;Y.-Y. Zhu;J.-H. Shi
Luminescence 2015 Volume 30( Issue 7) pp:1004-1010
Publication Date(Web):
DOI:10.1002/bio.2851
Abstract
The binding interaction of lovastatin with calf thymus DNA (ct-DNA) was studied using UV/Vis absorption spectroscopy, fluorescence emission spectroscopy, circular dichroism (CD), viscosity measurement and molecular docking methods. The experimental results showed that there was an obvious binding interaction of lovastatin with ct-DNA and the binding constant (Kb) was 5.60 × 103 M–1 at 298 K. In the binding process of lovastatin with ct-DNA, the enthalpy change (ΔH0) and entropy change (ΔS0) were –24.9 kJ/mol and –12.0 J/mol/K, respectively, indicating that the main binding interaction forces were van der Waal's force and hydrogen bonding. The molecular docking results suggested that lovastatin preferred to bind on the minor groove of different B-DNA fragments and the conformation change of lovastatin in the lovastatin–DNA complex was obviously observed, implying that the flexibility of lovastatin molecule plays an important role in the formation of the stable lovastatin–ct-DNA complex. Copyright © 2015 John Wiley & Sons, Ltd.
Co-reporter:Jie-Hua Shi, Ting-Ting Liu, Min Jiang, Jun Chen, Qi Wang
Journal of Photochemistry and Photobiology B: Biology 2015 Volume 147() pp:47-55
Publication Date(Web):June 2015
DOI:10.1016/j.jphotobiol.2015.03.005
•Gefitinib binds to ct-DNA via minor groove binding and forms 1:1 complex with it.•The main interaction forces were van der Waals and hydrogen bonding interactions.•There was slight change of the conformation of ct-DNA due to binding gefitinib.•The flexibility of gefitinib plays an important role in increasing the gefitinib–ct-DNA stability.The binding interaction of gefitinib with calf thymus DNA (ct-DNA) under the simulated physiological pH condition was studied employing UV absorption, fluorescence, circular dichroism (CD), viscosity measurement and molecular docking methods. The experimental results revealed that gefitinib preferred to bind to the minor groove of ct-DNA with the binding constant (Kb) of 1.29 × 104 L mol−1 at 298 K. Base on the signs and magnitudes of the enthalpy change (ΔH0 = −60.4 kJ mol−1) and entropy change (ΔS0 = −124.7 J mol−1 K−1) in the binding process and the results of molecular docking, it can be concluded that the main interaction forces between gefitinib and ct-DNA in the binding process were van der Waals force and hydrogen bonding interaction. The results of CD experiments revealed that gefitinib did not disturb native B-conformation of ct-DNA. And, the significant change in the conformation of gefitinib in gefitinib–ct-DNA complex was observed from the molecular docking results and the change was close relation with the structure of B-DNA fragments, indicating that the flexibility of gefitinib molecule also plays an important role in the formation of the stable gefitinib–ct-DNA complex.It has been confirmed that gefitinib interacts with ct-DNA via minor groove binding mode through spectroscopic methods (such as UV–vis absorption spectroscopy, fluorescence emission spectroscopy) and molecular doching.
Co-reporter:Guo-Feng Shen, Ting-Ting Liu, Qi Wang, Min Jiang, Jie-Hua Shi
Journal of Photochemistry and Photobiology B: Biology 2015 Volume 153() pp:380-390
Publication Date(Web):December 2015
DOI:10.1016/j.jphotobiol.2015.10.023
•The intrinsic fluorescence of BSA quenched by three TKIs due to forming stable TKIs–BSA•Lapatinib was located on site II (m) of BSA while gefitinib and sunitinib were bound on site I of BSA.•The main interaction forces were van der Waals and hydrogen bonding interactions.•There was slight change of the secondary structure of BSA due to binding to three TKIs.The binding interactions of three kinds of tyrosine kinase inhibitors (TKIs), such as gefitinib, lapatinib and sunitinib, with bovine serum albumin (BSA) were studied using ultraviolet spectrophotometry, fluorescence spectroscopy, circular dichroism (CD), Fourier transform infrared spectroscopy (FT-IR) and molecular docking methods. The experimental results showed that the intrinsic fluorescence quenching of BSA induced by the three TKIs resulted from the formation of stable TKIs–BSA complexes through the binding interaction of TKIs with BSA. The stoichiometry of three stable TKIs–BSA complexes was 1:1 and the binding constants (Kb) of the three TKIs–BSA complexes were in the order of 104 M− 1 at 310 K, indicating that there was a strong binding interaction of the three TKIs with BSA. Based on the analysis of the signs and magnitudes of the free energy change (ΔG0), enthalpic change (ΔH0) and entropic change (ΔS0) in the binding process, it can be deduced that the binding process of the three TKIs with BSA was spontaneous and enthalpy-driven process, and the main interaction forces between the three TKIs and BSA were van der Waals force and hydrogen bonding interaction. Moreover, from the results of CD, FT-IR and molecular docking, it can be concluded that there was a significant difference between the three TKIs in the binding site on BSA, lapatinib was located on site II (m) of BSA while gefitinib and sunitinib were bound on site I of BSA, and there were some changes in the BSA conformation when binding three TKIs to BSA but BSA still retains its secondary structure α-helicity.It has been confirmed that three TKIs interact with BSA via van der Waals and hydrogen bonding interactions through spectroscopic methods (such as UV–vis absorption spectroscopy, fluorescence emission spectroscopy) and molecular docking. It is important to note that the binding sites for different TKIs on BSA were different. Lapatinib was located on site II (m) of BSA while gefitinib and sunitinib were bound on site I of BSA.
Co-reporter:Jie-hua Shi;Jing Wang;Ying-yao Zhu;Jun Chen
Luminescence 2014 Volume 29( Issue 5) pp:522-530
Publication Date(Web):
DOI:10.1002/bio.2579
ABSTRACT
The intermolecular interaction between cyanidin-3-glucoside (Cy-3-G) and bovine serum albumin (BSA) was investigated using fluorescence, circular dichroism and molecular docking methods. The experimental results revealed that the fluorescence quenching of BSA at 338 nm by Cy-3-G resulted from the formation of Cy-3-G–BSA complex. The number of binding sites (n) for Cy-3-G binding on BSA was approximately equal to 1. The experimental and molecular docking results revealed that after binding Cy-3-G to BSA, Cy-3-G is closer to the Tyr residue than the Trp residue, the secondary structure of BSA almost not change, the binding process of Cy-3-G with BSA is spontaneous, and Cy-3-G can be inserted into the hydrophobic cavity of BSA (site II′) in the binding process of Cy-3-G with BSA. Moreover, based on the sign and magnitude of the enthalpy and entropy changes (ΔH0 = – 29.64 kcal/mol and ΔS0 = – 69.51 cal/mol K) and the molecular docking results, it can be suggested that the main interaction forces of Cy-3-G with BSA are Van der Waals and hydrogen bonding interactions. Copyright © 2013 John Wiley & Sons, Ltd.
Co-reporter:Jie-Hua Shi, Ke Chen, Yan Xu
Journal of Molecular Liquids 2014 194() pp: 172-178
Publication Date(Web):
DOI:10.1016/j.molliq.2014.01.023
Co-reporter:Jie-hua Shi;Shui-xing Xu;Qian-qian Jia;Xiao-qing Yan
Chromatographia 2013 Volume 76( Issue 15-16) pp:1021-1029
Publication Date(Web):2013 August
DOI:10.1007/s10337-013-2495-6
A novel cellulose trisphenylcarbamate/1-octyl-3-methylimidazolium tetrafluoroborate [CTPC/[OcMIM]BF4] gas chromatographic stationary phase was prepared and characterized utilizing thermodynamic parameters and LSER methodology. The results revealed that the interaction model of each probe molecule on the CTPC/[OcMIM]BF4 stationary phase was invariable within the temperature range studied because of an excellent linear relationship between lnk and 1/T for each probe molecule. The chromatographic retentions of all probe molecules on the CTPC/[OcMIM]BF4 stationary phase were enthalpy-driven processes. The main interaction forces of the stationary phase with probe molecules are hydrogen bonding interactions, dispersive interactions and dipole–dipole interactions. Moreover, the contribution of each interaction is in the order of hydrogen bonding interaction > dispersive interaction > dipole–dipole interaction. The mixture of CTPC and [OcMIM]BF4 used as capillary gas chromatography stationary phase had high column efficiency and good film-forming ability, which was suitable for the separation of both nonpolar and polar compounds. Particularly the separation efficiencies of aromatic amines on CTPC/[OcMIM]BF4 are superior to those on the commercial SE-54 column.
Co-reporter:Jie-hua Shi, Ying-Yao Zhu, Jing Wang, Jun Chen, Ya-Jing Shen
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2013 Volume 103() pp:287-294
Publication Date(Web):15 February 2013
DOI:10.1016/j.saa.2012.11.034
The intermolecular interaction of prednisolone with bovine serum albumin (BSA) was studied using fluorescence, circular dichroism (CD) and molecular docking methods. The experimental results showed that the fluorescence quenching of the BSA at 338 nm by prednisolone resulted from the formation of prednisolone–BSA complex. The number of binding sites (n) for prednisolone binding on BSA was approximately equal to 1. Base on the sign and magnitude of the enthalpy and entropy changes (ΔH0 = −149.6 kJ mol−1 and ΔS0 = −370.7 J mol−1 K−1) and the results of molecular docking, it could be suggested that the interaction forces were mainly Van der Waals and hydrogen bonding interactions. Moreover, in the binding process of BSA with prednisolone, prednisolone molecule can be inserted into the hydrophobic cavity of subdomain IIIA (site II) of BSA. The distance between prednisolone and Trp residue of BSA was calculated as 2.264 nm according to Forster’s non-radiative energy transfer theory.Graphical abstractThe binding complex was formed by Van der Waals and hydrogen bonding interactions between prednisolone and BSA, which the stoichiometry of prednisolone–BSA complex is 1:1 and the apparent binding constant (Kb) is 7.59 × 106 L mol −1 at 298 K in the Tris buffer solution (pH = 7.4). The experimental and molecular simulation results showed that prednisolone molecule can be inserted into the hydrophobic cavity of the subdomain IIIA (site II) of BSA..Research highlights► The interactions of prednisolone with BSA have been studied. ► The quenching of the BSA by prednisolone resulted from the formation of complex. ► The stoichiometry of prednisolone–BSA complex is 1:1. ► Prednisolone molecule can be inserted into the subdomain IIIA (site II) of BSA. ► The main interaction forces were Van der Waals and hydrogen bonding interactions.
Co-reporter:Jie-hua Shi, Chun-hui Fan
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2012 Volume 95() pp:230-234
Publication Date(Web):September 2012
DOI:10.1016/j.saa.2012.05.002
The intermolecular interactions between medroxyprogesterone acetate (MPA) and CHCl3 and CCl4 solvent in CHCl3/cyclo-C6H12 and CCl4/cyclo-C6H12 binary solvent systems have been studied by Fourier transform infrared spectroscopy (FT-IR). The experimental results showed that there are hydrogen bonding interactions between oxygen atoms of all carbonyl groups in MPA and hydrogen atom of CHCl3 so as to form 1:3 complex of MPA with CHCl3 and produce three new absorption bands at 1728.9–1736.1, 1712.7–1717.4 and 1661.9–1673.8 cm−1, respectively. And, 1:1 complex of MPA with CCl4 is formed in CCl4/cyclo-C6H12 binary solvent as a result of hydrogen bonding interaction between C3 carbonyl group and empty d-orbital in chlorine atom of CCl4 leading to producing new absorption band at 1673.2–1674.2 cm−1. However, all free carbonyl and associated carbonyl stretching vibrations of MPA in CHCl3/cyclo-C6H12 and CCl4/cyclo-C6H12 binary solvent systems shift to lower wavenumbers with the increasing of volume fraction of CHCl3 and CCl4 in binary solvent systems owing to the dipole–dipole interaction and the dipole–induced dipole interaction between MPA and solvents.Graphical abstractThe intermolecular interactions between medroxyprogesterone acetate (MPA) and CHCl3 and CCl4 solvent in CHCl3/cyclo-C6H12 and CCl4/cyclo-C6H12 binary solvent systems have been studied by Fourier transform infrared spectroscopy (FT-IR). The results showed that the associated molecules of medroxyprogesterone acetate (MPA) with CHCl3 and CCl4 can be formed by hydrogen bonding interaction of MPA with CHCl3 and CCl4 solvent. The stoichiometries of MPACHCl3 and MPACCl4 complexes are 1:3 and 1:1, respectively.Highlights► The interactions of MPA with CHCl3 and CCl4 have been studied by FT-IR. ► The MPA–CHCl3 and MPA–CCl4 complexes are formed by H-bonding interactions. ► The stoichiometries of MPA–CHCl3 and MPA–CCl4 complexes are 1:3 and 1:1, respectively.
Co-reporter:Jie-hua Shi;Qian-qian Jia;Shui-xing Xu
Chromatographia 2012 Volume 75( Issue 13-14) pp:779-787
Publication Date(Web):2012 July
DOI:10.1007/s10337-012-2256-y
A mixture of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetraethoxycarbonylmethyloxy calix[4]arene (C[4]TECM) and 1-octyl-3-methylimidazolium tetrafluoroborate ionic liquid (OmIm+BF4−) has been employed as stationary phases in capillary gas chromatography. Its properties have been characterized through thermodynamic parameters and linear solvation energy relationship. The experimental results showed that C[4]TECM–OmIm+BF4− mixture as gas chromatographic stationary phase has high column efficiency and peak symmetry, which were evaluated using naphthalene and n-octanol, respectively. It was demonstrated that the interaction forces between the probe molecules and the stationary phase did not change over the entire temperature range studied due to an excellent linear relationship between lnk and 1/T, the retentions of the probe molecules on the C[4]TECM–OmIm+BF4− stationary phase are enthalpy-driven processes, and the interactions of the probe molecules with C[4]TECM–OmIm+BF4− stationary phase mainly include hydrogen bonding interaction, dipole–dipole interaction and dispersive interaction. However, the contribution of each interaction is in the order of A > L > S for the C[4]TECM–OmIm+BF4− stationary phase.
Co-reporter:Jie-hua Shi, Ying Hu, Zuo-jing Ding
Computational and Theoretical Chemistry 2011 Volume 973(1–3) pp:62-68
Publication Date(Web):15 October 2011
DOI:10.1016/j.comptc.2011.07.001
The inclusion interactions between permethylated β-cyclodextrin (PMβCD) and enantiomers of ethyl-3-hydroxybutyrate ((R/S)-EHB) were simulated using the semi-empirical PM3 and ONIOM (B3LYP/6-31g(d):PM3) methods. The chiral recognition mechanism of (R/S)-EHB enantiomers on PMβCD was investigated. The modeling results showed that the most stable geometries of two (R/S)-EHB/PMβCD complexes were obviously different. The ethoxy group of (S)-EHB is nearly prostrated at the wider rim of PMβCD cavity, as the ethoxy group of (R)-EHB inserted into the hydrophobic cavity of PMβCD. The results showed that the binding energy (BE) and total stabilization energy (EONIOM) of (R)-EHB/PMβCD complex both are lower than that of (S)-EHB/PMβCD complex and the total charge transfer of (R)-EHB/PMβCD complex is greater than that of (S)-EHB/PMβCD, indicating that the (R)-EHB/PMβCD complex is more stable than the (S)-EHB/PMβCD complex. Furthermore, it can be deduced from the results obtained by NBO analysis that the main driving forces in the chiral recognitions of (R/S)-EHB enantiomers on PMβCD are weak hydrogen bonding interaction, dipole–dipole interaction, charge-transfer function and hydrophobic interaction, which leads to form different geometric structures of (R/S)-EHB/PMβCD complexes. However, in (R/S)-EHB/PMβCD complexes, the chiral carbon of (R/S)-EHB are both close to C2 and C3 in glucose units, so the chiral selector capacity is mainly due to the chiral environment provided by C2 and C3 in glucose units and the tightness of combining between (R/S)-EHB and PMβCD.Graphical abstractThe chiral recognition mechanism of (R/S)-EHB enantiomers on permethylated-β-cyclodextrin (PMβCD) mainly depends upon the different geometric structures of (R/S)-EHB/PMβCD complexes formed by intermolecular interaction (R/S)-EHB and PMβCD. The main driving forces in the chiral recognitions of (R/S)-EHB enantiomers on PMβCD are weak hydrogen bonding interaction, dipole–dipole interaction, charge-transfer function and hydrophobic interaction.Highlights► The inclusion interactions between PMβCD and enantiomers of (R/S)-EHB were simulated using PM3 and ONIOM methods. ► The binding geometries of the most stable (R/S)-EHB/PMβCD complexes obtained by ONIOM method are fully different. ► The (R)-EHB/PMβCD complex is more stable than (S)-EHB/PMβCD. ► The main driving forces are weak hydrogen bonding, dipole–dipole interaction, hydrophobic interaction, among others.
Co-reporter:Jie-hua Shi;Zuo-jing Ding;Ying Hu
Chromatographia 2011 Volume 74( Issue 3-4) pp:319-325
Publication Date(Web):2011 August
DOI:10.1007/s10337-011-2069-4
Enantioseparations of methyl mandelate (MMA) and methyl α-cyclohexylmandelate (MCHMA) on permethylated β-cyclodextrin (PM-β-CD) chiral stationary phase were explored in detail using high-performance liquid chromatography. The influence of the concentration of organic modifiers, along with the column temperature, was studied. In addition, the thermodynamics parameters of the enantioseparations were determined to discuss driven power in the process of enantioseparations. In addition, host−guest complexation of PM-β-CD with MMA enantiomers was simulated by quantum mechanics PM3 method for understanding the chiral recognition mechanism. The experimental results showed that the retention factor (k), separation factor (α), and resolution factor (Rs) for MMA and MCHMA resolved on the PM-β-CD column all generally decreased with the increase of methanol content, which indicated that the main chiral recognition mechanism is that the hydrophobic portions of MMA and MCHMA are included in the hydrophobic cavity of PM-β-CD to form inclusion complexes. In addition, there is an excellent linear relationship between the logarithms of retention factors (k) of MMA and MCHMA enantiomers and 1/T. It was demonstrated that the enantioseparations of MMA and MCHMA on PM-β-CD chiral column were enthalpy-driven processes. The modeling results can correctly predict the retention order and provide an atomistic account of how chiral discrimination takes place. It is found that the most stable structure of (R)-MMA/PM-β-CD complex is different with that of (S)-MMA/PM-β-CD complex. The main driving forces responsible for chiral recognition are hydrophobic forces and weak hydrogen bondings.
Co-reporter:Jie-Hua Shi, Ya-fang Zhou
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2011 Volume 83(Issue 1) pp:570-574
Publication Date(Web):December 2011
DOI:10.1016/j.saa.2011.09.005
The inclusion interaction between chloramphenicol and heptakis (2,6-di-O-methyl)-β-cyclodextrin (DMBCD) had been investigated by phase solubility and spectroscopic methods such as UV–vis spectroscopy, circular dichroism, Fourier transform infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance spectroscopy (1H NMR) as well as 2D-ROESY spectra. Phase solubility analysis showed AL-type diagram with DMBCD, which suggested the formation of 1:1 inclusion complex of DMBCD with chloramphenicol. The estimated stability constant (Ks) of the inclusion complex of chloramphenicol with DMBCD is 493 M−1 at 293 K. The solubility enhancement of chloramphenicol in the presence of DMBCD is stronger than that in the presence of β-CD, HP-β-CD and M-β-CD. The results obtained by spectroscopic methods showed that the nitrophenyl moiety of chloramphenicol is deeply inserted into inner cavity of DMBCD from the narrow rim of DMBCD, which the inclusion model of chloramphenicol with DMBCD differs from that with β-CD.Graphical abstractThere is interaction between chloramphenicol and DMBCD leading to producing 1:1 complex and increasing solubility of chloramphenicol in water. The results obtained by spectroscopic methods showed that the nitrophenyl moiety of chloramphenicol is deeply inserted into inner cavity of DMBCD from the narrow rim of DMBCD, which the inclusion model of chloramphenicol with DMBCD differs from that with β-CD.Highlights► 1:1 complex of chloramphenicol with DMBCD was formed by inclusion interaction. ► DMBCD had stronger ability of solubility enhancement for chloramphenicol. ► The nitrophenyl moiety of chloramphenicol is deeply inserted into cavity of DMBCD.
Co-reporter:Jie-Hua SHI, Yan YE
Chinese Journal of Analytical Chemistry 2010 Volume 38(Issue 10) pp:1450-1456
Publication Date(Web):October 2010
DOI:10.1016/S1872-2040(09)60072-4
Co-reporter:Jiehua Shi;Gao Pan
Frontiers of Chemistry in China 2009 Volume 4( Issue 2) pp:132-135
Publication Date(Web):2009 June
DOI:10.1007/s11458-009-0032-9
1-Butyl-3-methylimidazolium dodecatungstophosphate catalyst ([bmim]3PW12O40) with high water tolerance was prepared from 1-butyl-3-methylimidazolium bromide ([bmim]Br) and phosphotungstic acid (H3PW12O40). The catalyst was characterized by means of Fourier transform infrared spectroscopy, thermogravimetry-differential scanning calorimetry, n-BuNH2 potentiometric titration, elemental analysis and so on. Its catalytic activity for esterification of ethanol and acetic acid to ethyl acetate was measured. The results show that there were three crystal-water molecules in the [bmim]3PW12O40 catalyst, and it preserved the primary Keggin structure and acid strength of H3PW12O40. The acid amount of [bmim]3PW12O40 catalyst was less than that of H3PW12O40. The [bmim]3PW12O40 catalyst exhibited higher catalytic activity and reusability in the esterification of ethanol and acetic acid to ethyl acetate.
Co-reporter:Yan-Yue Lou, Kai-Li Zhou, Dong-Qi Pan, Jia-Le Shen, Jie-Hua Shi
Journal of Photochemistry and Photobiology B: Biology (February 2017) Volume 167() pp:158-167
Publication Date(Web):February 2017
DOI:10.1016/j.jphotobiol.2016.12.029
•The fluorescence of BSA quenched by clonazepam due to forming stable clonazepam-BSA complex.•Clonazepam located on the subdomain IIIA (Site II) of BSA•The interaction forces were mainly van der Waal's forces and hydrogen bonding interaction.•There was a slight change in the secondary structure of BSA due to binding clonazepam.•The flexibility of clonazepam played an important role in the binding process.Clonazepam, a type of benzodiazepine, is a classical drug used to prevent and treat seizures, panic disorder, movement disorder, among others. For further clarifying the distribution of clonazepam in vivo and the pharmacodynamic and pharmacokinetic mechanisms, the binding interaction between clonazepam and bovine serum albumin (BSA) was investigated using ultraviolet spectroscopy (UV), steady-state fluorescence spectroscopy, synchronous fluorescence spectroscopy, three-dimensional (3D) fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and molecular docking methods. The results well confirmed that clonazepam bound on the subdomain III A (Site II) of BSA through van der Waals force and hydrogen bonding interaction, and quenched the intrinsic fluorescence of BSA through a static quenching process. The number of binding sites (n) and binding constant (Kb) of clonazepam-BSA complex were about 1 and 7.94 × 104 M− 1 at 308 K, respectively. The binding process of clonazepam with BSA was spontaneous and enthalpy-driven process due to ΔG0 < 0 and | ΔH0 | > T | ΔS0 | over the studied temperature range. Meanwhile, the binding interaction of clonazepam with BSA resulted in the slight change in the conformation of BSA and the obvious change in the conformation of clonazepam, implying that the flexibility of clonazepam also played an important role in increasing the stability of the clonazepam–BSA complex.
