Very‐long‐chain Wax Constituents from Primula veris and P. acaulis: Does the Paradigm of Non‐branched vs. Branched Chain Dominance Universally Hold in all Plant Taxa?

Author(s):  
Milena Z. Živković Stošić ◽  
Niko S. Radulović ◽  
Marija S. Genčić ◽  
Vladimir N. Ranđelović
2001 ◽  
Vol 281 (6) ◽  
pp. G1333-G1339 ◽  
Author(s):  
Janardan K. Reddy

Peroxisomes are involved in the β-oxidation chain shortening of long-chain and very-long-chain fatty acyl-CoAs, long-chain dicarboxylyl-CoAs, the CoA esters of eicosanoids, 2-methyl-branched fatty acyl-CoAs, and the CoA esters of the bile acid intermediates, and in the process, they generate H2O2. There are two complete sets of β-oxidation enzymes present in peroxisomes, with each set consisting of three distinct enzymes. The classic PPARα-regulated and inducible set participates in the β-oxidation of straight-chain fatty acids, whereas the second noninducible set acts on branched-chain fatty acids. Long-chain and very-long-chain fatty acids are also metabolized by the cytochrome P-450 CYP4A ω-oxidation system to dicarboxylic acids that serve as substrates for peroxisomal β-oxidation. Evidence derived from mouse models of PPARα and peroxisomal β-oxidation deficiency highlights the critical importance of the defects in PPARα-inducible β-oxidation in energy metabolism and in the development of steatohepatitis.


1972 ◽  
Vol 29 (10) ◽  
pp. 1482-1486 ◽  
Author(s):  
David M. Schultz ◽  
James G. Quinn

The fatty acid composition of particulate matter from surface waters in the North Atlantic has been investigated. A high proportion is long-chain polyunsaturated acids, typical of a marine origin. The low relative abundance of iso and anteiso 15-carbon acids indicates little bacterial contribution to the particulate matter. This fatty acid distribution is in contrast to that found in estuarine particulate matter, which contains only trace amounts of the long-chain polyunsaturated acids and substantial quantities of branched chain acids.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Kosuke Kawaguchi ◽  
Masashi Morita

ATP-binding cassette (ABC) transporters are one of the largest families of membrane-bound proteins and transport a wide variety of substrates across both extra- and intracellular membranes. They play a critical role in maintaining cellular homeostasis. To date, four ABC transporters belonging to subfamily D have been identified. ABCD1–3 and ABCD4 are localized to peroxisomes and lysosomes, respectively. ABCD1 and ABCD2 are involved in the transport of long and very long chain fatty acids (VLCFA) or their CoA-derivatives into peroxisomes with different substrate specificities, while ABCD3 is involved in the transport of branched chain acyl-CoA into peroxisomes. On the other hand, ABCD4 is deduced to take part in the transport of vitamin B12from lysosomes into the cytosol. It is well known that the dysfunction of ABCD1 results in X-linked adrenoleukodystrophy, a severe neurodegenerative disease. Recently, it is reported that ABCD3 and ABCD4 are responsible for hepatosplenomegaly and vitamin B12deficiency, respectively. In this review, the targeting mechanism and physiological functions of the ABCD transporters are summarized along with the related disease.


2009 ◽  
Vol 160 ◽  
pp. S6
Author(s):  
Teymuras V. Kurzchalia ◽  
Eugeni V. Entchev ◽  
Dominik Schwudke ◽  
Vyacheslav Zagoriy ◽  
Vitali Matyash ◽  
...  

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2025 ◽  
Author(s):  
Peng Wang ◽  
Fu-quan Shi ◽  
Xi-yin Liu ◽  
Rui-bo Ren ◽  
Ying Zhu ◽  
...  

The anti-cracking properties of polymer-modified asphalt depend largely on the molecular structure of the polymer modifier. However, the mysterious structure-performance relationship is still elusive. In this paper, three kinds of polymers with different chain structures were selected to address this issue. The indices of styrene, trans-butadiene, aliphatic branched-chain, and aliphatic long-chain from the infrared spectrum were used to quantify the functional group compositions of polymer modifiers. Viscoelastic parameters, including relaxation time, dissipation energy ratios, and stiffness were assessed to illustrate the anti-cracking properties of polymer-modified asphalt. Results showed that relaxation time and dissipation energy ratios were mainly determined by the polymer network strength, molecular size, aliphatic chain feature, and the orientations speed of aliphatic chains. The short relaxation time and high dissipation ratio lead to the low stiffness and favorable low-temperature performance of asphalt. The improvement of these performances requires a polymer with high indices of an aliphatic long-chain, styrene, aliphatic branched-chain, and trans-butadiene, respectively. An aliphatic-long chain, aliphatic branched-chain, and trans-butadiene were soft segments in asphalt while styrene was the rigid segment. The soft segments affect the intramolecular friction, orientation, and thermal motion at low temperatures, whereas the rigid segment enhances the strength of polymer networks. Thus, the anti-cracking property of polymer-modified asphalt can be improved by adjusting the ratio of soft and rigid segments in the polymer modifier.


1962 ◽  
Vol 40 (1) ◽  
pp. 83-94 ◽  
Author(s):  
M. Kates ◽  
D. J. Kushner ◽  
A. T. James

Cells of Bacillus cereus grown in an alcohol-free medium (control cells) had a lipid content of 2.6 ± 0.4%, on a dry weight basis. About half of the lipids consisted of phosphatides, including phosphatidyl ethanolamine (40%), phosphatidyl glycerol (28%), lecithin (6%), lyso compounds (10%), and three acidic phosphatides of unknown structure. The fatty acids of the total lipids were predominantly saturated, the major components being branched-chain C13, C15, and C17acids. The neutral lipids consisted mostly of diglycerides, with a small amount of triglycerides. Five to ten per cent of the lipids was obtained as unsaponifiable material, consisting chiefly of long-chain (n-C16and n-C18) alcohols, and having traces of long-chain aldehydes (derived from plasmalogens).Cells grown in the presence of alcohols usually had a higher phosphatide content, a correspondingly lower non-phosphatide content, and a higher non-saponifiable content than control cells. Total lipid content or relative proportions of the phosphatide components in alcohol-grown cells did not differ significantly from those of control cells.


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