Sphingolipids have attracted significant attention due to their pivotal role in cellular functions and physiological diseases. A valuable tool for investigating the characteristics of sphingolipids can be represented via Fourier-transform infrared (FT-IR) spectroscopy, generally recognized as a very powerful technique that provides detailed biochemical information on the examined sample with the unique properties of sensitivity and accuracy.
Source | Url | Notes |
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Lipid Bank—Japanese Conference on the Biochemistry of Lipids (JCBL) | https://lipidbank.jp (accessed on 1 February 2023) | LipidBank is a free database of natural lipids including fatty acids, glycerolipids, SLs, steroids, and various vitamins.The database contains more than 6000 unique molecular structures, their lipid names, and spectral and literature information. |
NIST Chemistry WebBook | https://webbook.nist.gov (accessed on 1 February 2023) | The NIST Chemistry WebBook provides access to: thermochemical data; IR spectra, mass spectra, UV/Vis spectra, and gas chromatography data. It is possible to search for data on specific compounds based on name, chemical formula, CAS registry number, molecular weight, chemical structure, or selected ion energetics and spectral properties. |
Spectral Database for Organic Compounds (SDBS) | https://sdbs.db.aist.go.jp (accessed on 1 February 2023) | SDBS is an integrated spectral database system for organic compounds, which includes 6 different types of spectra: an electron impact mass spectrum (EI-MS), a Fourier-transform infrared spectrum (FT-IR), a 1H nuclear magnetic resonance (NMR) spectrum, a 13C NMR spectrum, a laser Raman spectrum, and an electron spin resonance (ESR) spectrum. |
Sphingolipid Compound | Structure |
---|---|
Ceramide (Cer) | |
Sphingosine 1-phosphate (S1P) | |
Sphingosine (SP) | |
Ceramide-1-phosphate (C1P) |
Peaks Position (cm−1) |
Assignments |
---|---|
892 | C=C bending (fatty acid) |
1050–1070 | C-O-C stretching (nucleic acids and phospholipids) |
Dihydroceramide | |
Sphingomyelin (SM) | |
Galactosylceramide | |
Lactosylceramide | |
Glucosylceramide |
1085–1090 | |
PO | -2 symmetric stretching (nucleic acids and phospholipid) |
1224–1240 | PO-2 asymmetric stretching (nucleic acids and phospholipid) |
1343 | CH2 wagging bending (phospholipid, fatty acid, and triglyceride) |
1367 | CH3 symmetric bending (lipids) |
1392–1400 | CH2 asymmetric bending, COO- stretching (proteins and fatty acids) |
1445–1470 | CH2 bending (mainly lipids and phospholipids, with little contribution from proteins) |
1456–1467 | CH3 bending (lipids, cholesterol, and proteins) |
1545–1549 | N-H bending (lipids) |
1660–1670 | C=C stretching (lipids, fatty acids) |
1730–1750 | C=O stretching (fatty acid ester, triglycerides, and cholesterol esters) |
2850–2865 | CH2 symmetric stretching (lipids, fatty acids) |
2870–2874 | CH3 symmetric stretching (protein side chains, lipids, with some contribution from carbohydrates and nucleic acids) |
2916–2925 | CH2 asymmetric stretching (mainly lipids, with little contribution from proteins, carbohydrates, and nucleic acids) |
2956–2970 | CH3 asymmetric stretching (lipids, fatty acids, protein side chains, with some contribution from carbohydrates and nucleic acids) |
3007–3015 | C-H stretching (lipids, unsaturated fatty acids) |
References | Lipid Extraction Method/Sample Details |
Spectra Collection Geometry | Aim | Main Findings |
---|---|---|---|---|
[71][99] | Commercial samples |
Transmission geometry using CaF2 windows | To investigate the molecular interactions between SM and PC in phospholipid vesicles. | The changes in the acyl chains and SM, conformation induced by PC are observed. |
[72][100] | Commercial samples |
Transmission geometry using CaF2 windows | To study the effects of temperature and pressure on structural and conformational properties of PC/SM/cholesterol model raft mixtures. |
The conformational properties of the lipid systems are monitored by examining the positions and intensities of infrared absorption bands. |
[73][74][101,102] | Rat brain tissue samples | Transmission geometry using CaF2 windows | To examine the spatial distribution of molecular changes associated with C6 glioma progression. | The concentrations of SM, nucleic acids, PS, and glucocerebroside are significantly affected during C6 glioma development. |
[75][103] | Lipids extracted from brain tissues using Folch and Bligh and Dyer methods. |
Transmission KBr pellets |
To analyze the lipid extracts from the brain to identify their composition. | Lipid content can be evaluated via FT-IR spectroscopy, which may improve the differential diagnosis of brain cancers. |
[76][77][104,105] | Commercial samples and lipids extracted from PC 3 cells using Bligh and Dyer method. | ATR | To analyze the changes in the lipidome of prostate cancer PC-3 cells after exposure to sub-lethal ouabain levels. | Lipid alterations induced by ouabain can be identified by variations in the ester/choline/phosphate ratios in FT-IR spectra. |
[68][96] | Commercial samples and lipids extracted from PC-3 cells using Bligh and Dyer method. | Micro-ATR | To develop PLS models based on FT-IR spectra to determine the changes in the amounts of different lipids in extracts from PC-3 cells treated with four antitumor drugs. | After treatments with anticancer drugs, the spectral region of the polar headgroups of samples did not show any noticeable alterations. However, the developed PLS models can be used for high-throughput measurements. |
[78][106] | Commercial samples |
ATR | To investigate the changes occurring in detergent-resistant membranes (DRM) extracted from human breast cancer cells when treated with the omega-3 fatty acid docosahexaenoic acid. | FT-IR spectroscopy and multivariate analysis enable to monitor of the changes in the composition of DRMs. This approach can be useful for the label-free characterization of lipid components in cells. |
[79][107] | Commercial samples |
Transmission geometry using CaF2 windows | To examine the interaction profile of carboplatin at varying concentrations with SM multilamellar vesicles. | Carboplatin affects the phase transition, enthalpy, the cooperativity parameter, the phase transition temperature, the lipid order, the lipid fluidity, and the hydrogen state of specific groups in hydrophilic parts of the examined samples. |