Raman and SERS study of N-acetyl-5-methoxytryptamine, melatonin—The influence of the different molecular fragments on the SERS effect

Fleming, Guillermo Díaz; Koch, Rainer; Pérez, José Muñoz; Cabrera, Jeanette Llanos

doi:10.1016/j.vibspec.2015.08.002

Cited by 15 publications

(11 citation statements)

References 59 publications

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“…From left side of Fig 8, two main spectral regions of the full IR spectrum of MEL have been located: (1) frequencies below 1800 cm −1 and (2) frequencies of 2700 < ω < 3600 cm −1 . As a general feature, the agreement of the calculated full spectrum with available data (at 0% cholesterol concentration) from infrared and Raman spectroscopy reported by Singh et al [72], Fleming et al [73] and Pieta et al [71] have revealed a very good overall agreement (see left side of Fig 8), although some discrepancies have been observed in the location of some peaks. As a general fact, the maxima reported by the three experimental groups match each other very well.…”

Section: Resultssupporting

confidence: 76%

Binding and dynamics of melatonin at the interface of phosphatidylcholine-cholesterol membranes

Martı́

2019

PLoS ONE

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The characterization of interactions between melatonin, one main ingredient of medicines regulating sleeping rhythms, and basic components of cellular plasma membranes (phospholipids, cholesterol, metal ions and water) is very important to elucidate the main mechanisms for the introduction of melatonin into cells and also to identify its local structure and microscopic dynamics. Molecular dynamics simulations of melatonin inside mixtures of dimyristoylphosphatidylcholine and cholesterol in NaCl solution at physiological concentration have been performed at 303.15 K to systematically explore melatonin-cholesterol, melatonin-lipid and melatonin-water interactions. Properties such as the area per lipid and thickness of the membrane as well as selected radial distribution functions, binding free energies, angular distributions, atomic spectral densities and translational diffusion of melatonin are reported. The presence of cholesterol significantly affects the behavior of melatonin, which is mainly buried into the interfaces of membranes. Introducing cholesterol into the system helps melatonin change from folded to extended configurations more easily. Our results suggest that there exists a competition between the binding of melatonin to phospholipids and to cholesterol by means of hydrogen-bonds. Spectral densities of melatonin reported in this work, in overall good agreement with experimental data, revealed the participation of each atom of melatonin to its complete spectrum. Melatonin self-diffusion coefficients are of the order of 10−7 cm2/s and they significantly increase when cholesterol is addeed to the membrane.

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Section: Resultssupporting

confidence: 76%

Binding and dynamics of melatonin at the interface of phosphatidylcholine-cholesterol membranes

Martı́

2019

PLoS ONE

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“…In order to support Scheme 1, in Figure 7, the Raman spectra of MEL, before and after its interaction with NaOH, are shown. According to Figure 7a, the Raman lines of MEL are situated at 347, 403, 507, 636, 713, 757, 835, 927, 956, 1024, 1080, 1176, 1251, 1296, 1357, 1448, 1550, 1589, 1627, and 2829-3132 cm −1 , which are attributed to the vibrational modes of -COC twisting in anisole, CH2 twisting in indole acetamide, the in-plan bending of anisole, NH out-of-plane bending NH in acetamide amide IV, CH2 rocking in methylene, C-H out-of-plane bending in indole (pyrrole), C-H out-of-plan bending in indole (benzene), CCC bending mode in indole acetamide, phenyl breathing + CH3 rocking in anisole, ring-in-plane bending in indole, O-CH3 + pyrrole CCC bending in anisoleindole, CH3 out-of-plane rocking in acetamide anisole, CH2 wagging in methylene, NCH in-plane bending in indole, NH bending + CN stretching + C=C stretching in acetamide amide III, NH bending + C-N + C=O stretching in acetamide amide II, NH in-plane bending in the acetamide group, C-C ring stretching in indole, C=O stretching + C-N stretching + CCN deformation in acetamide amide I, and CH3 + CH2 + NH stretching [19]. The main changes observed in the Raman spectrum as a consequence of the interaction of MEL with NaOH are as follows: (i) a down-shift of the lines from 636, 1448, and 2829 cm −1 to 624, 1444, and 2813 cm −1 , respectively, (ii) an up-shift of the lines from 927, 1080, 1357, 1550, and 1589 cm −1 to 933, 1087, 1363, 1561, and 1594 cm −1 , respectively, and (iii) the presence of two In Figures 5 and 6, the PL band with the maximum around 420-423 nm is noted only in the case of the NaOH solution with the highest concentration.…”

Section: Raman Scattering and Ir Spectroscopy Studies Concerning The mentioning

confidence: 99%

Photoluminescence as a Complementary Tool for UV-VIS Spectroscopy to Highlight the Photodegradation of Drugs: A Case Study on Melatonin

et al. 2020

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In this work, a complementary ultraviolet-visible (UV-VIS) spectroscopy and photoluminescence (PL) study on melatonin (MEL) hydrolysis in the presence of alkaline aqueous solutions and the photodegradation of MEL is reported. The UV-VIS spectrum of MEL is characterized by an absorption band with a peak at 278 nm. This peak shifts to 272 nm simultaneously with an increase in the band absorbance at 329 nm in the presence of an NaOH solution. The isosbestic point localized at 308 nm indicates the generation of some chemical compounds in addition to MEL and NaOH. The MEL PL spectrum is characterized by a band at 365 nm. There is a gradual decrease in the MEL PL intensity as the alkaline solution concentration added at the drug solution is increased. In the case of the MEL samples interacting with an alkaline solution, a new photoluminescence excitation (PLE) band at 335 nm appears when the exposure time to UV light reaches 310 min. A down-shift in the MEL PLE band, from 321 to 311 nm, as a consequence of the presence of excipients, is also shown. These changes are explained in reference to the MEL hydrolytic products.

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“…It was found that the molecular structure and surface affinity influence the sensitivity, and the molecules with the strongest affinity for the surface will have the highest signal-to-noise in SERS experiments [ 31 ]. Raman and SERS measurements of melatonin [ 32 ] and serotonin [ 33 ] have been performed along with DFT calculations that focused on the interaction and adsorption of the different parts of the molecule to the Au and Ag surfaces, respectively. The DFT structural parameters and harmonic vibrational wavenumbers found for melatonin correlate well with the experimental data [ 32 ].…”

Section: Neurological Diseasesmentioning

confidence: 99%

“…Raman and SERS measurements of melatonin [ 32 ] and serotonin [ 33 ] have been performed along with DFT calculations that focused on the interaction and adsorption of the different parts of the molecule to the Au and Ag surfaces, respectively. The DFT structural parameters and harmonic vibrational wavenumbers found for melatonin correlate well with the experimental data [ 32 ]. The adsorption structure of serotonin formed on an Ag electrode surface changes with negative potential shifts followed by complete detachment from the Ag surface [ 33 ].…”

Section: Neurological Diseasesmentioning

confidence: 99%

In Vitro and In Vivo SERS Biosensing for Disease Diagnosis

et al. 2018

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For many disease states, positive outcomes are directly linked to early diagnosis, where therapeutic intervention would be most effective. Recently, trends in disease diagnosis have focused on the development of label-free sensing techniques that are sensitive to low analyte concentrations found in the physiological environment. Surface-enhanced Raman spectroscopy (SERS) is a powerful vibrational spectroscopy that allows for label-free, highly sensitive, and selective detection of analytes through the amplification of localized electric fields on the surface of a plasmonic material when excited with monochromatic light. This results in enhancement of the Raman scattering signal, which allows for the detection of low concentration analytes, giving rise to the use of SERS as a diagnostic tool for disease. Here, we present a review of recent developments in the field of in vivo and in vitro SERS biosensing for a range of disease states including neurological disease, diabetes, cardiovascular disease, cancer, and viral disease.

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Raman and SERS study of N-acetyl-5-methoxytryptamine, melatonin—The influence of the different molecular fragments on the SERS effect

Cited by 15 publications

References 59 publications

Binding and dynamics of melatonin at the interface of phosphatidylcholine-cholesterol membranes

Binding and dynamics of melatonin at the interface of phosphatidylcholine-cholesterol membranes

Photoluminescence as a Complementary Tool for UV-VIS Spectroscopy to Highlight the Photodegradation of Drugs: A Case Study on Melatonin

In Vitro and In Vivo SERS Biosensing for Disease Diagnosis

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