scholarly journals An improved procedure for the preparation of alkyl sulphate esters suitable for the study of secondary alkylsulphohydrolase enzymes

1980 ◽  
Vol 187 (1) ◽  
pp. 191-196 ◽  
Author(s):  
G F White ◽  
V Lillis ◽  
D J Shaw
Keyword(s):  
Hydroxy Group ◽  
Convenient Method ◽  
Carbon Chain ◽  
Alkyl Sulphate ◽  
Positional Isomerization ◽  
Sodium Alkoxide ◽  
Long Chain

A simple, rapid and convenient method for the synthesis of secondary alkyl sulphate esters is described in which the sodium alkoxide of the parent alcohol is sulphated by using triethylamine-SO3 complex. The procedure gives relatively good yields, even for the sulphation of long-chain alcohols and those in which the hydroxy group is remote from the terminal carbon atoms. Positional isomerization, arising from the migration of the hydroxy group along the carbon chain, is absent, and resolved enantiomers of alcohols react with complete retention of configuration.

The Use of N-alkanes for Estimating Intake and Passage Rate in Horses

1996 ◽  
Vol 1996 ◽  
pp. 98-98
Author(s):  
B M L McLean ◽  
R W Mayes ◽  
F D DeB Hovell
Keyword(s):  
Recent Work ◽  
Chain Length ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Passage Rate ◽  
Forage Crops ◽  
Carbon Chains ◽  
Naturally Occurring ◽  
Chain Lengths ◽  
Long Chain

Alkanes occur naturally in all plants, although forage crops tend to have higher alkane contents than cereals. N-alkanes have odd-numbered carbon chains. They are ideal for use as markers in feed trials, because, they are inert, indigestible and naturally occurring, and can be recovered in animal faeces. Synthetic alkanes (even-numbered carbon chains) are available commercially and can also used as external markers. Dove and Mayes (1991) cite evidence indicating that faecal recovery of alkanes in ruminants increases with increasing carbon-chain length. Thus the alkane “pairs” (e.g. C35 & C36, and C32 & C33) are used in calculating intake and digestibility because they are long chain and adjacent to each other. However, recent work by Cuddeford and Mayes (unpublished) has found that in horses the faecal recovery rates are similar regardless of chain lengths.

scholarly journals The occurrence of polyenoic very long chain fatty acids with greater than 32 carbon atoms in molecular species of phosphatidylcholine in normal and peroxisome-deficient (Zellweger's syndrome) brain

1988 ◽  
Vol 253 (3) ◽  
pp. 645-650 ◽  
Author(s):  
A Poulos ◽  
P Sharp ◽  
D Johnson ◽  
C Easton
Keyword(s):  
Fatty Acids ◽  
Molecular Species ◽  
Carbon Chain ◽  
Normal Brain ◽  
Long Chain Fatty Acids ◽  
Brain Physiology ◽  
Chain Lengths ◽  
The Brain ◽  
Long Chain ◽  
Chain Fatty Acids

The n-6 tetra- and pentaenoic fatty acids with carbon chain lengths greater than 32 found in normal brain are located predominantly in a separable species of phosphatidylcholine. A similar phospholipid is found in increased amounts in the brain of peroxisome-deficient (Zellweger's syndrome) patients, but the fatty acid composition differs in that penta- and hexaenoic derivatives predominate. Our data strongly suggest that the polyenoic very long chain fatty acids are confined to the sn-1 position of the glycerol moiety, while the sn-2 position is enriched in saturated, monounsaturated and polyunsaturated fatty acids with less than 24 carbon atoms. It is postulated that these unusual molecular species of phosphatidylcholine may play some, as yet undefined, role in brain physiology.

Studies of the optically active compounds of Anacardiaceae exudates. V. Further investigation of the exudate from Campnosperma auriculata Hook. F

1959 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
JA Lamberton
Keyword(s):  
Convenient Method ◽  
Aldol Reaction ◽  
Optically Active ◽  
Improved Method ◽  
Alcoholic Alkali ◽  
Active Compounds ◽  
Hydrogenated Oil ◽  
Alkyl Phenols ◽  
Long Chain

Distillation of the hydrogenated oil from Campnosperma auriculata Hook. f. yields n-pentacosane-2,6-dione (IV), which is formed from (+)-3-hydroxy-3-nonadecylcyclohexanone (II) by a retro-aldol reaction. In alcoholic alkali, IV is recyclized to 3-nona-decylcyclohex-2-enone (III), and on Wolff-Kishner reduction the disemicarbazone of IV yields n-pentacosane. Oxidation of 3-nonadecylcyclohex-2-enone (III) yields 5-ketotetracosanoic acid, which has been synthesized by an improved method. The synthesis of III and of 3-heptadecylcyclohex-2-enone is described and a convenient method is given for the preparation of 3-methylcyclohex-2-enone. Examination of the mixture of phenols obtained by the action of alkali on C. auriculata oil has shown the presence of 3-nonadecyl phenol and a mixture composed predominantly of cis-monoethylenic C,, alkyl phenols. The phenols are admixed with a small amount of certain long-chain quinols which are also present in the original oils. Nonadecylquinol, one component, has been characterized by conversion into nonadecyl-benzoquinone. The exudate from Campnosperma macrophylla Hook. f. (also Malayan) is unlike that from C. auriculata and contains little oil.

scholarly journals Unique molecular species of phosphatidylcholine containing very-long-chain (C24-C38) polyenoic fatty acids in rat brain

1990 ◽  
Vol 265 (3) ◽  
pp. 763-767 ◽  
Author(s):  
B S Robinson ◽  
D W Johnson ◽  
A Poulos
Keyword(s):  
Fatty Acids ◽  
Rat Brain ◽  
Molecular Species ◽  
Carbon Chain ◽  
Neonatal Rat ◽  
Adult Rat ◽  
Adult Rat Brain ◽  
Chain Lengths ◽  
Neonatal Rat Brain ◽  
Long Chain

Rat brain has been shown to contain polyenoic very-long-chain fatty acids (VLCFA) belonging to the n-3 and n-6 series with four, five and six double bonds and even-carbon chain lengths from 24 to 38. These fatty acids are almost exclusively located in unusual molecular species of phosphatidylcholine at the sn-1 position of the glycerol backbone, whereas saturated, monoenoic and polyenoic fatty acids with less than 24 carbon atoms are present at the sn-2 position. Polyenoic VLCFA phosphatidylcholine in neonatal rat brain is enriched with n-6 pentaenoic and n-3 hexaenoic VLCFA with up to 36 carbon atoms, whereas the corresponding phospholipid in adult rat brain mainly contains n-6 tetraenoic and n-3 pentaenoic VLCFA with up to 38 carbon atoms. The total amount of polyenoic VLCFA associated with phosphatidylcholine is highest in the brain of immature animals. Polyenoic VLCFA phosphatidylcholine appears to be predominantly confined to nervous tissue in rats, and it is envisaged that this phospholipid is of physiological significance.

scholarly journals Chemically defined inducers of alkylsulphatases present in Pseudomonas C12B

1974 ◽  
Vol 138 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Kenneth S. Dodgson ◽  
John W. Fitzgerald ◽  
William J. Payne
Keyword(s):  
Secondary Alcohol ◽  
Sodium Dodecyl ◽  
Nutrient Broth ◽  
Phase Cell ◽  
Alkyl Sulphate ◽  
Cell Extracts ◽  
Complex Process ◽  
Commercial Detergent ◽  
Process Studies ◽  
Long Chain

When Pseudomonas C12B is grown on nutrient broth to the stationary phase, cell extracts contain two secondary alkylsulphatases (S1 and S2) active towards potassium decan-5-yl sulphate but not towards potassium pentan-3-yl sulphate and one primary alkylsulphatase (P1) active towards sodium dodecan-1-yl sulphate (sodium dodecyl sulphate). When 10mm-sodium hexan-1-yl sulphate is included in the nutrient broth an additional primary alkylsulphatase (P2) is produced. The S1, S2, P1 and P2 enzymes are also present in extracts of cells grown on broth containing the commercial detergent Oronite, together with an additional secondary alkylsulphatase (S3) active towards pentan-3-yl sulphate as well as decan-5-yl sulphate. The P2 primary alkylsulphatase can be induced by a number of primary and secondary alkyl sulphate esters but the induction of the S3 enzyme appears to be a more specific and complex process. Studies on the ability of different fractions separated from Oronite to act as inducers suggest that the combination of a long-chain secondary alkyl sulphate(s) and a long-chain secondary alcohol(s) is responsible for the appearance of the S3 enzyme. Potassium hexadecan-2-yl sulphate or potassium tetradecan-2-yl sulphate, in combination with either hexadecan-2-ol or tetradecan-2-ol, can serve as inducers for the enzyme. Some characteristics of these specific inducer systems have been elucidated.

scholarly journals Polyenoic very-long-chain fatty acids mobilize intracellular calcium from a thapsigargin-insensitive pool in human neutrophils. The relationship between Ca2+ mobilization and superoxide production induced by long- and very-long-chain fatty acids

1995 ◽  
Vol 311 (2) ◽  
pp. 689-697 ◽  
Author(s):  
S J Hardy ◽  
B S Robinson ◽  
A Ferrante ◽  
C S T Hii ◽  
D W Johnson ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
Carbon Chain ◽  
Superoxide Production ◽  
Human Neutrophils ◽  
Carbon Chain Length ◽  
Long Chain Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids

Fatty acids with more than 22 carbon atoms (very-long-chain fatty acids; VLCFAs) are normal cellular components that have been implicated in the pathophysiology of a number of peroxisomal disorders. To date, however, essentially nothing is known regarding their biological activities. Ca2+ mobilization is an important intracellular signalling system for a variety of agonists and cell types. Given that several polyunsaturated long-chain fatty acids mobilize intracellular Ca2+ and that we have postulated that the VLCFAs may be involved in signal transduction, we examined whether the tetraenoic VLCFA induced Ca2+ mobilization in human neutrophils. We report that fatty acid-induced intracellular Ca2+ mobilization declined for fatty acid species of more than 20 carbon atoms, but increased again as the carbon chain length approached 30. This Ca2+ mobilization occurred independently of inositol 1,4,5-triphosphate production and protein kinase C translocation and involved both the release of Ca2+ from the intracellular stores and changes to the influx or efflux of the ion. We further observed that triacontatetraenoic acid [30:4(n-6)] mobilized Ca2+ from a thapsigargin-insensitive intracellular pool distinct from the thapsigargin-sensitive pools affected by arachidonic acid [20:4(n - 6)] or N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP). 20:4 (n - 6) induced strong superoxide production (chemiluminescence) which was inhibited by thapsigargin pretreatment. In contrast, fatty acid-induced superoxide production progressively declined as the carbon chain length increased beyond 20-22 carbon atoms. Further studies suggested that the thapsigargin-insensitive Ca2+ mobilization elicited by 30:4 (n - 6) was not related to oxyradical formation, while the thapsigargin-sensitive Ca2+ mobilization induced by 20:4 (n - 6) may be involved in the initiation but not necessarily the maintenance of superoxide production. In conclusion, this is the first report to demonstrate a biological activity for the VLCFA and indicates that 30:4 (n - 6) influences second messenger systems in intact cells that differ from those affected by long-chain fatty acids such as 20:4 (n - 6).

scholarly journals The Adsorption Selectivity of Short and Long Per- and Polyfluoroalkyl Substances (PFASs) from Surface Water Using Powder-Activated Carbon

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3287
Author(s):  
Heejong Son ◽  
Taehoon Kim ◽  
Hoon-Sik Yoom ◽  
Dongye Zhao ◽  
Byungryul An
Keyword(s):  
Activated Carbon ◽  
Surface Water ◽  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Carbon Chain ◽  
Adsorption Selectivity ◽  
Mixing Intensity ◽  
Polyfluoroalkyl Substances ◽  
Powder Activated Carbon ◽  
Long Chain

Nine per- and polyfluoroalkyl substances (PFASs), including six perfluoroalkyl carboxylic acids (PFCAs) and three perfluoroalkyl sulfonic acids (PFSAs), were tested to find their adsorption selectivity from surface water and the feasibility of the powder activated carbon (PAC) process between the perchlorination and coagulation processes by operating parameters such as mixing intensity, dosage, contact time, initial pH, and concentration of perchlorination. The removal efficiency of four types of PAC revealed that the coal-based activated carbon was clearly advanced for all of the PFASs, and the thermal regenerated PAC did not exhibit a significant reduction in adsorption capacity. The longer carbon chain or the higher molecular weight (MW) obtained a higher adsorption capacity and the MW exhibited a more proportional relationship with the removal efficiency than the carbon chain number, regardless of the PFCA and PFSA species. Approximately 80% and 90% equilibria were accomplished within 60 and 120 min for the long chain carbon PFAS, respectively, while for the short chain PFAS, 240 min was required to reach 85% equilibrium. The effect of mixing intensity (rpm) was not considered for the removal of the PFAS, although it was relatively influenced in the short PFAS species. Due to the surface charge of the PAC and the properties of protonation of the PFASs, the acid condition increased the PFASs’ adsorption capacity. The prechlorination decreased the removal efficiency, and the reduction rate was more significantly influenced for the short chain PFAS than for the long chain PFAS.

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