title: Potential benefits of triethylamine as n-electron donor in the estimation of forskolin by electronic absorption and emission spectroscopy.
abstract: Diterpenoid forskolin was isolated from Coleus forskolii. The electronic absorption and emission studies of forskolin were investigated in various solvents with an aim to improve its detection limits. The two chromophores present in the diterpenoid are not conjugated leading to the poor absorption and emission of UV light. The absorption and fluorescence spectra were solvent specific. In the presence of a monodentate ligand, triethylamine the detection of forskolin is improved by 3.63 times in ethanol with the fluorescence method and 3.36 times in DMSO by the absorption spectral method. The longer wavelength absorption maximum is blue shifted while the lower energy fluorescence maximum is red shifted in the presence of triethylamine. From the wavelength of fluorescence maxima of the exciplex formed between excited forskolin and triethylamine it is concluded that the order of reactivity of hydroxyl groups in the excited state forskolin is in the reverse order to that of the order of the reactivity of hydroxyl groups in its ground state.
authors.affiliation: Department of Chemistry, University College of Science, Osmania University Campus, Hyderabad-500 007, India.
authors.forename: Gajula
authors.initials: G
authors.lastname: Raju
authors.affiliation: Department of Chemistry, University College of Science, Osmania University Campus, Hyderabad-500 007, India. Electronic address: a_ramreddy@yahoo.com.
authors.forename: A
authors.initials: A
authors.lastname: Ram Reddy
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005576:Colforsin / Q000032:analysis* / Q000302:isolation & purification; D004583:Electrons; D005021:Ethylamines / Q000737:chemistry*; D031346:Plectranthus / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D005021:Ethylamines; D005576:Colforsin; C016162:triethylamine
keywords: Electronic spectra; Forskolin; Monodentate ligand