A method for the separation of seed oil steryl esters and free sterols: Application to peanut and corn oils

1984 ◽  
Vol 61 (6) ◽  
pp. 1085-1088 ◽  
Author(s):  
R. E. Worthington ◽  
H. L. Hitchcock
Keyword(s):  
Seed Oil ◽  
Free Sterols ◽  
Steryl Esters

scholarly journals Studies on the Free Sterols, Steryl Esters and Glycerides

1966 ◽  
Vol 87 (8) ◽  
pp. 867-869 ◽  
Author(s):  
Yoko NAYA ◽  
Munio KOTAKE
Keyword(s):  
Free Sterols ◽  
Steryl Esters

Extractives in bark of different conifer species growing in Pakistan

Holzforschung ◽  
2009 ◽  
Vol 63 (5) ◽  
Author(s):  
Stefan Willför ◽  
Mumtaz Ali ◽  
Maarit Karonen ◽  
Markku Reunanen ◽  
Mohammad Arfan ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Short Chain Fatty Acids ◽  
Resin Acids ◽  
Fatty Alcohols ◽  
Pinus Roxburghii ◽  
Cedrus Deodara ◽  
Free Sterols ◽  
Steryl Esters ◽  
Common Fatty Acid ◽  
Chain Fatty Acids

Abstract The amount and composition of lipophilic and hydrophilic extractives, including proanthocyanidins, has been analysed as a first screening in the bark of six Pakistani coniferous tree species, namely Pinus wallichiana, Pinus roxburghii, Pinus gerardiana, Abies pindrow, Taxus fuana and Cedrus deodara. The predominant lipophilic extractives were common fatty and resin acids, fatty alcohols and sterols. In all bark samples, short-chain fatty acids were more abundant than long-chain fatty acids. Generally, the amount of free fatty acids was also larger than the amount of triglycerides. Oleic acid was the most common fatty acid, except in C. deodara, where lignoceric acid dominated. The largest amounts of fatty acids and fatty alcohols were found in P. wallichiana and P. gerardiana. P. gerardiana contained an exceptionally large amount of resin acids, approximately 3% of the bark weight, compared to the other species. The amount of free sterols was approximately at the same level or larger than the amount of steryl esters in most samples. In addition to proanthocyanidins, different known lignans, stilbenes, ferulates and flavonoids were generally predominant amongst the hydrophilic extractives. Resveratrol glycoside was abundant in P. wallichiana, while C. deodara and P. gerardiana contained large amounts of lignans and lignan derivatives. All bark extracts contained large amounts of proanthocyanidin-related catechin and its derivatives. Furthermore, C. deodara and P. roxburghii contained quite large amounts of taxifolin. In particular, P. wallichiana and A. pindrow are potential rich sources of proanthocyanidins, representing approximately 16% and 5% of the bark weight, respectively.

Comparison of Lipids and Fatty Acids of the Lichen Rhizoplaca Peltata Collected from Foothill and High Mountain Habitats in the Same Region

1996 ◽  
Vol 28 (5) ◽  
pp. 465-469
Author(s):  
Irene A. Bychek ◽  
Eugene A. Bychek
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Acid Content ◽  
Fatty Acid Content ◽  
Lichen Species ◽  
Wax Esters ◽  
High Mountain ◽  
Free Sterols ◽  
Steryl Esters ◽  
Mountain Habitats

AbstractLipids and fatty acids from the lichen Rhizoplaca peltata, growing either high in the mountains or in nearby foothills, were analysed and compared. It was shown that the same lichen species had considerable differences in the content of triacylglycerols, free sterols, wax esters, steryl esters, glycolipids, betaine and phospholipids, as well as in fatty acid content, depending on altitude.

scholarly journals Lipid Changes in Mature-green Tomatoes during Ripening, during Chilling, and after Rewarming subsequent to Chilling

1994 ◽  
Vol 119 (5) ◽  
pp. 994-999 ◽  
Author(s):  
Bruce D. Whitaker
Keyword(s):  
Fatty Acid ◽  
Lycopersicon Esculentum ◽  
Lipid Composition ◽  
Total Sterol ◽  
Sterol Composition ◽  
Detectable Level ◽  
Pigment Content ◽  
Free Sterols ◽  
Steryl Esters ◽  
Fatty Acid Unsaturation

Lipid composition and pigment content were determined in pericarp of `Pik Red' tomatoes (Lycopersicon esculentum Mill.) that were harvested when mature-green (MG) then ripened for 1 or 14 days at 20C, chilled for 11 or 21 days at 2C, or chilled for 21 days and transferred to 20C for 4 days (rewarmed). During ripening, chlorophyll fell below a detectable level, carotenes increased 100-fold, phospholipids (PLs) dropped ≈20%, and galactolipids (GLs) dropped ≈35%. Fatty-acid unsaturation decreased slightly. Steryl esters (SEs), more than free sterols (FSs) and steryl glycosides (SGs), increased at the expense of acylated steryl glycosides (ASGs), and in all four steryl lipids, the stigmasterol: sitosterol ratio rose dramatically, whereas the level of isofucosterol fell sharply. During chilling, chlorophyll declined ≈40% and carotenes ≈60%. PL content did not change, whereas GL fell ≈15%. Fatty-acid unsaturation increased slightly. FS, much more than SG and SE, increased at the expense of ASG. The stigmasterol: sitosterol ratio changed little in ASG, SG, and SE but declined in FS. Isofucosterol increased in FS and SE. Rewarming had little effect on the levels of chlorophyll, carotenes, or PL levels, but caused GL to fall another ≈15%. Fatty-acid unsaturation decreased slightly in GL and ASG. The distribution of total sterol in ASG, SG, FS, and SE changed dramatically, yielding proportions close to those in unchilled MG fruit. Also, 4 days after rewarming, the stigmasterol: sitosterol ratio had increased sharply, particularly in FS and SE, and there was a further rise in isofucosterol in all four steryl lipids. These results indicate that chloroplast damage occurs during chilling, but PL-rich cell membranes are not degraded, even upon rewarming. Changes in sterol composition and conjugation during chilling and after rewarming could result in membrane dysfunction.

Enzymatic conversion of steryl esters to free sterols

2003 ◽  
Vol 80 (3) ◽  
pp. 243-247 ◽  
Author(s):  
Yuji Shimada ◽  
Toshihiro Nagao ◽  
Youichi Watanabe ◽  
Yoshiaki Takagi ◽  
Akio Sugihara
Keyword(s):  
Enzymatic Conversion ◽  
Free Sterols ◽  
Steryl Esters

scholarly journals The Saccharomyces cerevisiae YLL012/YEH1, YLR020/YEH2, and TGL1 Genes Encode a Novel Family of Membrane-Anchored Lipases That Are Required for Steryl Ester Hydrolysis

2005 ◽  
Vol 25 (5) ◽  
pp. 1655-1668 ◽  
Author(s):  
René Köffel ◽  
Rashi Tiwari ◽  
Laurent Falquet ◽  
Roger Schneiter
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Steryl Ester ◽  
Ester Hydrolysis ◽  
Open Reading Frames ◽  
Yeast Cells ◽  
Acid Lipase ◽  
Triple Mutant ◽  
Free Sterols ◽  
Steryl Esters

ABSTRACT Sterol homeostasis in eukaryotic cells relies on the reciprocal interconversion of free sterols and steryl esters. The formation of steryl esters is well characterized, but the mechanisms that control steryl ester mobilization upon cellular demand are less well understood. We have identified a family of three lipases of Saccharomyces cerevisiae that are required for efficient steryl ester mobilization. These lipases, encoded by YLL012/YEH1, YLR020/YEH2, and TGL1, are paralogues of the mammalian acid lipase family, which is composed of the lysosomal acid lipase, the gastric lipase, and four novel as yet uncharacterized human open reading frames. Lipase triple-mutant yeast cells are completely blocked in steryl ester hydrolysis but do not affect the mobilization of triacylglycerols, indicating that the three lipases are required for steryl ester mobilization in vivo. Lipase single mutants mobilize steryl esters to various degrees, indicating partial functional redundancy of the three gene products. Lipase double-mutant cells in which the third lipase is expressed from the inducible GAL1 promoter have greatly reduced steady-state levels of steryl esters, indicating that overexpression of any of the three lipases is sufficient for steryl ester mobilization in vivo. The three yeast enzymes constitute a novel class of membrane-anchored lipases that differ in topology and subcellular localization.

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