Molecular and vibrational structure of the extracellular bacterial signal compound N-butyryl-homoserine lactone (C4-HSL)

Molecular and vibrational structure of thiosulfonate S-esters

“…The molecular equilibrium configurations were determined by B3LYP/cc-pVTZ geometry optimization in the gas phase and vibrational frequencies were computed within the harmonic approximation. In previous investigations, we have found that this level of theory leads to good agreement with the molecular and vibrational structure for a variety of organic compounds [17][18][19][20][21]. variation of the two rotation angles from 0°to 360°in steps of 30°, yielding a grid of 13 Â 13 = 169 points.…”

Sorption characteristics ofN-acyl homserine lactones as signal molecules in natural soils based on the analysis of kinetics and isotherms

“…Very similar vibrational features were expected for all AHLs due to their analogous molecular structures. 57 The spectra were dominated by six strong bonds at 3311, 1777, 1644, 1551, 1175 and 1025 cm −1 , which could be assigned to the characteristic vibrations of the amide and lactone functional groups. 57 After the sorption of AHLs on the two soils, the 3311 cm −1 band shifted to 3316 cm −1 , the band at 1644 cm −1 disappeared and the peak at 1549 cm −1 remained unchanged ( Fig.…”

“… 57 The spectra were dominated by six strong bonds at 3311, 1777, 1644, 1551, 1175 and 1025 cm −1 , which could be assigned to the characteristic vibrations of the amide and lactone functional groups. 57 After the sorption of AHLs on the two soils, the 3311 cm −1 band shifted to 3316 cm −1 , the band at 1644 cm −1 disappeared and the peak at 1549 cm −1 remained unchanged ( Fig. 5 ), and these peaks could be easily assigned to the key vibrations of the amide group, i.e.…”

Detection of the Quorum Sensing Signal Molecule N-Dodecanoyl-DLHomoserine Lactone Below 1 Nanomolar Concentrations using Surface Enhanced Raman Spectroscopy

“…Raman spectroscopy has furthermore been used to study the metabolic states of bacteria [6], and the cultivation time dependence of bacterial cellular surface biopolymers [ 7]. In the work by Bak et al the infrared spectra of the AHL N-butanoyl-L-homoserine lactone (C4-HSL) in the crystalline form and dissolved in CCl 4 have been measured and the IR and the Raman spectra have been calculated using Gaussian03 with the B3LYP hybrid exchange correlation functional (Kohn Sharm, density functional theory) and the cc-pVTZ basis set for the solid state cluster model (a trimer mode)l [8]. In general, symmetric vibrations give the largest scattering cross section in Raman spectroscopy, while the asymmetric vibrations are the most intense in IR spectroscopy.…”