UV spectral properties of lipids as a tool for their identification

Angioni, Elisabetta; Lercker, G.; Frega, Natale G.; Carta, Gianfranca; Melis, Maria Paola; Murru, Elisabetta; Spada, Simona; Banni, Sebastiano

doi:10.1002/1438-9312(200201)104:1<59::aid-ejlt59>3.3.co;2-9

Cited by 3 publications

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“…Separation of cholesteryl esters was carried out as described in [28] with an Agilent 1100 HPLC system (Agilent, Palo Alto, CA) equipped with a diode array detector and mass spectrometer in line. UV and mass spectra were recorded to confirm the identification of the HPLC peaks [29]. Cholesterol esterified with conjugated linoleic acid (18:2 CLA), a fatty acid biosynthesized exclusively in the rumen and characteristic of the tissues and milk of ruminants [30] was likewise identified using the above method.…”

Section: Analysis Of Free Cholesterol and Cholesteryl Esters In Mediamentioning

confidence: 92%

A lipoprotein source of cholesteryl esters is essential for proliferation of CEM-CCRF lymphoblastic cell line

et al. 2011

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Tumour are characterised by a high content of cholesteryl esters (CEs) stored in lipid droplets purported to be due to a high rate of intracellular esterification of cholesterol. To verify whether and which pathways involved in CE accumulation are essential in tumour proliferation, the effect of CE deprivation, from both exogenous and endogenous sources, on CEM-CCRF cells was investigated. Cholesterol synthesis, esterification and content, low-density lipoprotein (LDL) binding and high-density lipoprotein (HDL)-CE uptake were evaluated in cultured in both conventional and delipidated bovine serum with or without oleic or linoleic acids, cholesteryl oleate, LDL and HDL. High content of CEs in lipid droplets in this cell line was due to esterification of both newly synthesised cholesterol and that obtained from hydrolysis of LDL; moreover, a significant amount of CE was derived from HDL-CE uptake. Cell proliferation was slightly affected by either acute or chronic treatment up to 400 μM with Sz-58035, an acyl-cholesteryl cholesterol esterification inhibitor (ACAT); although when the enzyme activity was continuously inhibited, CE content in lipid droplets was significantly higher than those in control cells. In these cells, analysis of intracellular and medium CEs revealed a profile reflecting the characteristics of bovine serum, suggesting a plasma origin of CE molecules. Cell proliferation arrest in delipidated medium was almost completely prevented in the first 72 h by LDL or HDL, although in subsequent cultures with LDL, it manifested an increasing mortality rate. This study suggests that high content of CEs in CEM-CCRF is mainly derived from plasma lipoproteins and that part of CEs stored in lipid droplets are obtained after being taken up from HDL. This route appears to be up-regulated according to cell requirements and involved in low levels of c-HDL during cancer. Moreover, the dependence of tumour cells on a source of lipoprotein provides a novel impetus in developing therapeutic strategies for use in the treatment of some tumours.

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Section: Analysis Of Free Cholesterol and Cholesteryl Esters In Mediamentioning

confidence: 92%

A lipoprotein source of cholesteryl esters is essential for proliferation of CEM-CCRF lymphoblastic cell line

et al. 2011

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Quantification Method for Triglyceride Molecular Species in Fish Oil with High Performance Liquid Chromatography-Ultraviolet Detector

et al. 2004

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Triglyceride (TG) is a principal component of fats and oils and consists of three fatty acids and one glycerol. Many kinds of fatty acids exist in natural fats and oils and partake in TG molecular construction. Consequently, in the case of the combinations of fatty acids are different between two TG molecular, these two TG molecular are distinguished as different kinds of TG molecular species (1). The analysis of TG molecular species is usually conducted with high performance liquid chromatography (HPLC), and silver ion column or reverse phase (RP) column is employed for the separation of TG molecular species (2,3). Silver ion column separates TG molecular species in order of the degree of unsaturation (4-6). On the contrary, RP column separates them in order of the polarity (7-9). Both of them have been well hired for the TG molecular species sep- JAPAN) Abstract: A new quantification method for triglyceride (TG) molecular species contained in fish oil was developed using high performance liquid chromatography (HPLC)-ultraviolet detector (UV) system. In this experiment, triacontyl silane column and a mixture of alcohol and acetonitrile were used for column and mobile phase, respectively. Fifteen kinds of TG molecular species exist in fish oil were collected and the calibration curves monitored at 210nm were acquired for each TG molecular species. Also, evaporative light scattering detector (ELSD), widely used for the detection of fish oil TG molecular species, was tandem jointed after UV to compare the calibration curves for each TG molecular species. As the results, the calibration curves by UV with isocratic elution system were linear lines, on the contrary, those by ELSD were not linear. The slope of each calibration curve by UV was not the same and there was a tendency that TG molecular species having big partition number indicates a small slope calibration curve. The HPLC-UV with gradient system was also examined, but a few of standard TGs did not provide linear calibration curve. Consequently, we concluded that isocratic HPLC-UV system would be an available method for the quantification of TG molecular species in fish oil. 285 JOSKey words: quantification, triglyceride molecular species, fish oil, HPLC-UV, triacontyl silane column (15) and expressed with the equation of PN=TC-2xDB, where TC is total carbon number of acyl group and DB is total number of double bond in TG. In this system, TG molecular species are eluted in order of PN and this rule can be adapted for every kind of oils and fats such as plant oil, animal fat, milk fat and fish oil (2,3). However, the separation of TG molecular species in milk fat and/or fish oil is not enough compared to those in plant oil or animal fat, because milk fat and/or fish oil consists of more kinds of TG molecular species than plant oil and animal fat (2,3). Therefore, some kinds of efforts, such as gradient elution system, are made in order to obtain fine separation of TG molecular species in milk fat or fish oil (16-18). The selection of the detector is al...

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Studies on the Molecular Species of Naturally Occurring Lipids and its Preservation for Food Functionality

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2006

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UV spectral properties of lipids as a tool for their identification

Cited by 3 publications

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A lipoprotein source of cholesteryl esters is essential for proliferation of CEM-CCRF lymphoblastic cell line

A lipoprotein source of cholesteryl esters is essential for proliferation of CEM-CCRF lymphoblastic cell line

Quantification Method for Triglyceride Molecular Species in Fish Oil with High Performance Liquid Chromatography-Ultraviolet Detector

Studies on the Molecular Species of Naturally Occurring Lipids and its Preservation for Food Functionality

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