Raman spectroscopy of lipids: a review

Abstract

Raman spectra of 35 lipids are presented and analyzed in this work. Selected compounds, i.e. saturated/unsaturated fatty acids, triacylglycerols, cholesterol, cholesteryl esters and phospholipids, were chosen to review key lipids involved in cardiovascular disease development. Differences in Raman signatures both between diverse groups of lipids as well as various members of the same family are investigated in detail in order to elucidate marker features enabling detection and discrimination of lipids in complex samples, particularly of biological origin. This work complements our previous review on important biomolecules, i.e. proteins, and presents a comprehensive database of Raman spectra of naturally occurring lipids. Scheme 1. Chemical structure of chosen fatty acids: saturated (a) and unsaturated (b). Raman spectroscopy of lipids

Comparative Study of the Lipid Profiles of Oils from Kernels of Peanut, Babassu, Coconut, Castor and Grape by GC-FID and Raman Spectroscopy

“…The tentative assignments of the bands, based on pertinent literature, [38][39][40][41] are presented in Table 2.…”

“…In particular, the enlargement one can be ascribed to the breaking of the spectral degeneracy by the nonequivalence of the carbons in the polymer chains. 40 The Raman spectra of the vegetable oils are shown in Figures 2 and 3. The assignments of the features were performed based on the Raman spectra of the standard fatty acids and the data are presented in Table 3.…”

D38-cholesterol as a Raman active probe for imaging intracellular cholesterol storage

“…25 Note also that it is not straightforward to discriminate subpopulations of lipid droplets based on the degree of cholesterol esterification by using Raman spectroscopy without the use of the D38-cholesterol probe. The characteristic C═O stretching mode of ester groups at 1740 cm −1 , which serves as a marker for cholesteryl esters, 43 is not only weak, but also overlaps spectrally with ester group vibrations of triacylglycerols. Given that triacylglycerols are ubiquitous in lipid droplets, the 1740 cm −1 marker band cannot be readily used as a unique probe for cholesteryl esters.…”

Raman Spectroscopy of cultural heritage Materials: Overview of Applications and New Frontiers in Instrumentation, Sampling Modalities, and Data Processing

“…These cover a wide range of materials, from pigments and minerals to organic media and plastics, and have been listed in recent reviews [61,103,171,283,284,294,296]. Among these, some pioneering studies and major databases are worth mentioning.…”

“…3.4. It is well known that in the past 15 years numerous excellent reviews and special issues of journals (especially the Journal of Raman Spectroscopy) have been dedicated to in-depth overviews of all manners of application of Raman spectroscopy in art, archaeology, forensics, and gemology, and the reader is referred to these for a comprehensive treatment of the subject [24,48,77,103,171,283,284,294,296]. Many dedicated books are also available [68,76,125].…”