title: Host-guest interaction of 3-hydroxyflavone and 7-hydroxyflavone with cucurbit [7]uril: A spectroscopic and calorimetric approach.
abstract: The modulation of photophysical behaviour of small organic molecules in the presence of macrocycles is one of the most interesting areas of research. In this work we reported the interaction of two biologically active molecules 3-hydroxyflavone and 7-hydroxyflavone with macrocyclic host cucurbit [7]uril in aqueous medium. To investigate the change of photophysical properties of these two flavones, we have used steady state absorption, fluorescence, time resolved fluorescence emission spectroscopy and isothermal titration calorimetric technique. It is observed that on complexation with cucurbit [7]uril, the excited state proton transfer processes in both flavones have been facilitated. Isothermal titration calorimetric method was used in order to investigate the involvement of thermodynamic parameters in complexation between flavone with cucurbit [7]uril. The changes in thermodynamic properties due to the complexation of the flavones molecules with cucurbit [7]urils help to understand about the governing parameters involved in this complexation. The inclusion of flavone molecules inside the cavity of cucurbit [7]uril molecules was studied theoretically to decipher the molecular orientation of flavones in the presence of cucurbit [7]uril. The structure of HOMO and LUMO of the complexes between cucurbit [7]uril with flavones was reported. This study will be helpful to get the knowledge about the modulation of photophysical properties of the flavones molecules on addition of macrocyclic host cucurbit [7]uril. This study will be helpful for the use of cucurbit [7]uril as a potential drug delivery system.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Patna, Patna, 801103, Bihar, India.
authors.forename: Sayeed Ashique
authors.initials: SA
authors.lastname: Ahmed
authors.affiliation: Department of Chemistry, Indian Institute of Technology Patna, Patna, 801103, Bihar, India.
authors.forename: Banibrata
authors.initials: B
authors.lastname: Maity
authors.affiliation: Department of Chemistry, Nabadwip Vidyasagar College, West Bengal, India.
authors.forename: Soma Seth
authors.initials: SS
authors.lastname: Duley
authors.affiliation: Department of Chemistry, Indian Institute of Technology Patna, Patna, 801103, Bihar, India. Electronic address: debabrata@iitp.ac.in.
authors.forename: Debabrata
authors.initials: D
authors.lastname: Seth
mesh_terms: D001665:Binding Sites; D001952:Bridged-Ring Compounds / Q000737:chemistry*; D002151:Calorimetry; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods*; D005419:Flavonoids / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D015394:Molecular Structure; D013057:Spectrum Analysis; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils
chemical_list: D001952:Bridged-Ring Compounds; D004337:Drug Carriers; D005419:Flavonoids; D007093:Imidazoles; C456276:cucurbit(7)uril; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils; C429845:7-hydroxyflavone; C041477:3-hydroxyflavone
keywords: 3-hydroxyflavone; 7-hydroxyflavone; Cucurbit [7]uril; ITC; Supramolecular interaction