Efficient Asymmetric Synthesis of Long-Chain Polyketides Containing up to Ten Contiguous Stereogenic Centres by Double Chain Elongation

2011 ◽  
Vol 2011 (18) ◽  
pp. 3317-3328 ◽  
Author(s):  
Maris Turks ◽  
Kelly A. Fairweather ◽  
Rosario Scopelliti ◽  
Pierre Vogel
Keyword(s):  
Asymmetric Synthesis ◽  
Chain Elongation ◽  
Double Chain ◽  
Long Chain

In vivo study of the biosynthesis of long-chain fatty acids using deuterated water

1995 ◽  
Vol 269 (2) ◽  
pp. E247-E252 ◽  
Author(s):  
H. O. Ajie ◽  
M. J. Connor ◽  
W. N. Lee ◽  
S. Bassilian ◽  
E. A. Bergner ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
De Novo ◽  
Chain Elongation ◽  
Deuterated Water ◽  
De Novo Synthesis ◽  
Isotopomer Distribution ◽  
Long Chain ◽  
Mass Isotopomer

To determine the contributions of preexisting fatty acid, de novo synthesis, and chain elongation in long-chain fatty acid (LCFA) synthesis, the synthesis of LCFAs, palmitate (16:0), stearate (18:0), arachidate (20:0), behenate (22:0), and lignocerate (24:0), in the epidermis, liver, and spinal cord was determined using deuterated water and mass isotopomer distribution analysis in hairless mice and Sprague-Dawley rats. Animals were given 4% deuterated water for 5 days or 8 wk in their drinking water. Blood was withdrawn at the end of these times for the determination of deuterium enrichment, and the animals were killed to isolate the various tissues for lipid extraction for the determination of the mass isotopomer distributions. The mass isotopomer distributions in LCFA were incompatible with synthesis from a single pool of primer. The synthesis of palmitate, stearate, arachidate, behenate, and lignocerate followed the expected biochemical pathways for the synthesis of LCFAs. On average, three deuterium atoms were incorporated for every addition of an acetyl unit. The isotopomer distribution resulting from chain elongation and de novo synthesis can be described by the linear combination of two binomial distributions. The proportions of preexisting, chain elongation, and de novo-synthesized fatty acids as a percentage of the total fatty acids were determined using multiple linear regression analysis. Fractional synthesis was found to vary, depending on the tissue type and the fatty acid, from 47 to 87%. A substantial fraction (24-40%) of the newly synthesized molecules was derived from chain elongation of unlabeled (recycled) palmitate.

scholarly journals Asymmetric Synthesis and Binding Study of New Long-Chain HPA-12 Analogues as Potent Ligands of the Ceramide Transfer Protein CERT

2016 ◽  
Vol 22 (19) ◽  
pp. 6676-6686 ◽  
Author(s):  
Andrej Ďuriš ◽  
Adam Daïch ◽  
Cécile Santos ◽  
Laurence Fleury ◽  
Frédéric Ausseil ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Binding Study ◽  
Transfer Protein ◽  
Long Chain

ChemInform Abstract: Preparation of the Novel Long Chain β-Amino Acids and Their Conversion to F-Alkylated Double-Chain Carboxybetains.

ChemInform ◽  
2010 ◽  
Vol 30 (23) ◽  
pp. no-no
Author(s):  
D. Enjalbert ◽  
C. Bassilana ◽  
V. Krier ◽  
S. Szoenyi ◽  
A. Cambon
Keyword(s):  
Amino Acids ◽  
The Novel ◽  
Double Chain ◽  
Long Chain

scholarly journals The synthesis and hydrolysis of long-chain fatty acyl-coenzyme A thioesters by soluble and microsomal fractions from the brain of the developing rat

1976 ◽  
Vol 160 (2) ◽  
pp. 247-251 ◽  
Author(s):  
P J Brophy ◽  
D E Vance
Keyword(s):  
Fatty Acid ◽  
Microsomal Fraction ◽  
Specific Activity ◽  
Arachidic Acid ◽  
Fatty Acyl ◽  
Chain Elongation ◽  
Fatty Acid Chain ◽  
Specific Activities ◽  
Coa Hydrolase ◽  
Long Chain

1. The specific activities of long-chain fatty acid-CoA ligase (EC6.2.1.3) and of long-chain fatty acyl-CoA hydrolase (EC3.1.2.2) were measured in soluble and microsomal fractions from rat brain. 2. In the presence of either palmitic acid or stearic acid, the specific activity of the ligase increased during development; the specific activity of this enzyme with arachidic acid or behenic acid was considerably lower. 3. The specific activities of palmitoyl-CoA hydrolase and of stearoyl-CoA hydrolase in the microsomal fraction decreased markedly (75%) between 6 and 20 days after birth; by contrast, the corresponding specific activities in the soluble fraction showed no decline. 4. Stearoyl-CoA hydrolase in the microsomal fraction is inhibited (99%) by bovine serum albumin; this is in contrast with the microsomal fatty acid-chain-elongation system, which is stimulated 3.9-fold by albumin. Inhibition of stearoyl-CoA hydrolase does not stimulate stearoyl-CoA chain elongation. Therefore it does not appear likely that the decline in the specific activity of hydrolase during myelogenesis is responsible for the increased rate of fatty acid chain elongation. 5. It is suggested that the decline in specific activity of the microsomal hydrolase and to a lesser extent the increase in the specific activity of the ligase is directly related to the increased demand for long-chain acyl-CoA esters during myelogenesis as substrates in the biosynthesis of myelin lipids.

Vacuolar chain elongation of raffinose oligosaccharides in Ajuga reptans

2000 ◽  
Vol 27 (9) ◽  
pp. 743 ◽  
Author(s):  
Renate Braun ◽  
Felix Keller
Keyword(s):  
Osmotic Shock ◽  
Subcellular Location ◽  
Assimilate Transport ◽  
Chain Elongation ◽  
Raffinose Family Oligosaccharides ◽  
Raffinose Oligosaccharides ◽  
Ajuga Reptans ◽  
Key Enzyme ◽  
Autumn And Winter ◽  
Long Chain

This paper originates from a presentation at the International Conference on Assimilate Transport and Partitioning, Newcastle, NSW, August 1999 Galactan : galactan galactosyltransferase (GGT) is the key enzyme responsible for the accumulation of long-chain raffinose family oligosaccharides (RFOs; α-D-galn(1,6) α-D-glc(1,2) β-D-fru) in Ajuga reptans L. leaves during autumn and winter. The exact subcellular location of GGT is not known and its elucidation was the aim of this paper. A method for the isolation of vacuoles from A. reptans mesophyll protoplasts was developed using a pH and osmotic shock to rupture the plasma membrane selectively. By comparing protoplasts with vacuoles, GGT was confirmed to be a vacuolar enzyme. By comparing vacuoles with tonoplast vesicles and cell sap fractions, GGT was further shown to reside in the cell sap and not in the tonoplast. These findings suggest the need for a tonoplast-bound mechanism for the transport of short-chain RFOs such as stachyose or raffinose into the vacuole for subsequent chain elongation.

Asymmetric synthesis of new chiral long chain alcohols

2010 ◽  
Vol 21 (24) ◽  
pp. 2981-2987 ◽  
Author(s):  
Tülay Yıldız ◽  
Ayşe Yusufoğlu
Keyword(s):  
Asymmetric Synthesis ◽  
Long Chain
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