title: Raman spectroscopic study of the Chromobacterium violaceum pigment violacein using multiwavelength excitation and DFT calculations.
abstract: Violacein is a bisindole pigment occurring as a biosynthetic product of Chromobacterium violaceum and Janthinobacterium lividum. It has some structural similarities to the cyanobacterial UV-protective pigment scytonemin, which has been the subject of comprehensive spectroscopic and structural studies. A detailed experimental Raman spectroscopic study with visible and near-infrared excitation of violacein produced by C. violaceum has been undertaken and supported using theoretical DFT calculations. Raman spectra with 514 and 785 nm excitation of cultivated cells as well as extracts and Gaussian (B3LYP/6-311++G(d,p)) calculations with proposed molecular vibrational assignments are reported here.
authors.affiliation: Charles University in Prague, Institute of Geochemistry, Mineralogy and Mineral Resources, Albertov 6, 128 43 Prague, Czech Republic. Electronic address: jehlicka@natur.cuni.cz.
authors.forename: Jan
authors.initials: J
authors.lastname: Jehlička
authors.affiliation: Centre for Astrobiology and Extremophiles Research, School of Life Sciences, University of Bradford, Bradford BD7 1DP, UK.
authors.forename: Howell G M
authors.initials: HG
authors.lastname: Edwards
authors.affiliation: Charles University in Prague, Department of Inorganic Chemistry, Hlavova 8, 128 43 Prague, Czech Republic.
authors.forename: Ivan
authors.initials: I
authors.lastname: Němec
authors.affiliation: Department of Plant and Environmental Sciences, The Institute of Life Sciences, The Hebrew University of Jerusalem, The Edmond J. Safra Campus Givat Ram, 91904 Jerusalem, Israel.
authors.forename: Aharon
authors.initials: A
authors.lastname: Oren
mesh_terms: D002861:Chromobacterium / Q000378:metabolism*; D007211:Indoles / Q000032:analysis* / Q000378:metabolism*; D008958:Models, Molecular; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D007211:Indoles; C063155:violacein
keywords: Cyanobacteria; DFT calculations; Raman spectroscopy; UV protective pigment