Related Experiment Video
Updated: May 4, 2026
04:37
Author Spotlight: Understanding Rhamnolipid Regulation in Pseudomonas aeruginosa
Published on: March 29, 2024
2.3K
(-)-R-mevalonolactone studied by ROA and SERS spectroscopy
Katarzyna Chruszcz-Lipska1, Aleksandra Jaworska, Ewelina Szczurek
1Jagiellonian Centre for Experimental Therapeutics, Jagiellonian University, Krakow, Poland.
Chirality
|January 17, 2014
Summary
This study presents the first experimental and theoretical Raman optical activity (ROA) spectra for (-)-R-mevalonolactone. Calculations reveal significant conformational diversity due to subtle energy differences in its ring and hydroxyl group arrangements.
Area of Science:
- Spectroscopy
- Quantum Chemistry
- Organic Chemistry
Background:
- (-)-R-mevalonic acid is a precursor in cholesterol biosynthesis.
- Understanding its lactone form's conformation is crucial for biochemical studies.
- Raman optical activity (ROA) provides stereochemical information.
Purpose of the Study:
- To determine the experimental and theoretical Raman optical activity (ROA) spectra of (-)-R-mevalonolactone.
- To investigate the conformational diversity of (-)-R-mevalonolactone in different environments.
- To analyze the vibrational spectra of (-)-R-mevalonolactone adsorbed on silver nanoparticles.
Main Methods:
- Density Functional Theory (DFT) calculations using B3LYP/6-311++G**.
- Experimental measurement of ROA spectra in neat liquid and aqueous solution.
- Acquisition of normal Raman and Surface-Enhanced Raman Spectroscopy (SERS) spectra.
Main Results:
- Calculations predicted significant conformational diversity for (-)-R-mevalonolactone.
- The predominant conformation is a chair form with an axial hydroxyl group, but other conformers contribute.
- Experimental and theoretical ROA spectra were successfully obtained and compared.
- Normal Raman and SERS spectra of adsorbed (-)-R-mevalonolactone were also presented.
Conclusions:
- The study elucidates the conformational landscape of (-)-R-mevalonolactone.
- DFT calculations accurately predict the observed spectral features.
- ROA spectroscopy is a valuable tool for characterizing chiral molecules like (-)-R-mevalonolactone.
Keywords:
Raman optical activityRaman spectroscopymevalonolactonequantum-chemical calculationssurface enhanced Raman spectroscopyMore Related Videos
Related Concept Videos
01:20Raman Spectroscopy: Overview
2.6K
The underlying principle of Raman spectroscopy is based on the interaction between light and matter, specifically molecules' inelastic scattering of photons. When a monochromatic beam of light, typically from a laser source, interacts with a sample, most scattered light has the same frequency as the incident light. This is known as Rayleigh scattering.
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and...
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and...
2.6K
01:26Spectroscopy of Carboxylic Acid Derivatives
2.2K
Infrared spectroscopy is primarily used to determine the types of bonds and functional groups. In carboxylic acid derivatives, a typical carbonyl bond absorption is observed around 1650–1850 cm−1. For esters, the absorption is recorded at around 1740 cm−1, while acid halides show the absorption at about 1800 cm−1. Another acid derivative, the acid anhydrides, exhibit two carbonyl absorption around 1760 cm−1 and 1820 cm−1, arising from the symmetrical and...
2.2K
01:26Raman Spectroscopy Instrumentation: Overview
1.8K
A conventional Raman spectrophotometer includes a laser source, a sample holding system, a wavelength selector, and a detector.
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...
1.8K
01:14NMR Spectroscopy of Aromatic Compounds
4.7K
Aromatic compounds can be identified or analyzed using proton NMR and carbon‐13 NMR. Typically, aromatic hydrogens or hydrogens directly bonded to the aromatic rings are strongly deshielded by the aromatic ring current. Therefore, they absorb in the range of 6.5–8.0 ppm in proton NMR spectra. For instance, aromatic hydrogens directly bonded to the benzene ring absorb at 7.3 ppm. However, aromatic hydrogens of larger rings absorb farther upfield or downfield than the ideal range.
4.7K
01:37NMR Spectroscopy of Benzene Derivatives
10.3K
Simple unsubstituted benzene has six aromatic protons, all chemically equivalent. Therefore, benzene exhibits only a singlet peak at δ 7.3 ppm in the 1H NMR spectrum. The observed shift is far downfield because the aromatic ring current strongly deshields the protons. Any substitution on the benzene ring makes the aromatic protons nonequivalent, and the protons split each other. The peak is, therefore, no longer a singlet and the splitting pattern and their associated coupling...
10.3K
01:28IR and UV–Vis Spectroscopy of Carboxylic Acids
4.6K
In IR spectroscopy of carboxylic acids, the C=O bond shows a characteristic band between 1710 and 1760 cm⁻¹, and the O–H bond exhibits a broad band between 2500 and 3300 cm⁻¹.
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency,...
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency,...
4.6K