Low temperature solubilities of fatty acids in selected organic solvents

Kolb, Doris; Brown, J. B.

doi:10.1007/bf02640385

Cited by 38 publications

(20 citation statements)

References 15 publications

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“…The relationship between solubility and rate of activation of long chain fatty acids is unclear. Kolb and Brown concluded that solubility of the A6 and A9 cis-octadecenoates was proportional to the distance of the double bond from the carboxyl group (9). However the increased solubility that would result as the double bond is moved from carbon 9 to carbon 17 would not be correlated with the activation profile observed in the present study.…”

Section: Discussioncontrasting

confidence: 63%

Activation of long chain fatty acids by subcellular fractions of rat liver: III. Effect of ethylenic bond position on acyl‐CoA formation ofcis‐octadecenoates

Lippel

Carpenter

Gunstone

et al. 1973

Lipids

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The rates of rat liver microsomal and mitochondrial activation of the Δ4 to Δ17cis‐octadecenoate positional isomers have been investigated. The fatty acid to protein ratios required for maximum activation of the Δ8, Δ9 and Δ10 isomers were much lower than the corresponding ratios required for maximum activation of thecis‐octadecenoates with double bonds at either end of the fatty acid molecule. Also, as the incubation temperature was raised from 22–38 C the Δ8 and Δ9 isomers exhibited little change in their rates of activation, while large increases in activation rates of the isomers with the double bond at either end of the fatty acid chain were observed. Differential inhibition of the activation of the various positional isomers was observed when anionic, cationic, or nonionic detergents were included in the incubation medium. The different responses to fatty acid concentration, temperature and detergents are attributed to enzyme specificity and to differences in solution properties of thecis‐octadecenoates, rather than to the presence of separate rat liver enzymes that catalyze acyl‐CoA ester formation of the various positional isomers.

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Section: Discussioncontrasting

confidence: 63%

Activation of long chain fatty acids by subcellular fractions of rat liver: III. Effect of ethylenic bond position on acyl‐CoA formation ofcis‐octadecenoates

Lippel

Carpenter

Gunstone

et al. 1973

Lipids

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“…Thus Farmer & van den Heuvel (1938) have criticized the use of conventional vacuum-distillation techniques, and several authors have criticized the polybromide method on the grounds that structural alteration of such labile molecules can, and probably does, occur. Kolb & Brown (1955) have pointed out that the usefulness of low-temperature fractional-crystallization procedures may be limited by mutual-solubility effects.…”

mentioning

confidence: 99%

South african pilchard oil. 5. The isolation and structure of an eicosapentaenoic acid from South African pilchard oil

Whitcutt

Sutton

1956

Biochemical Journal

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PROTOPORPHYRIN IN SHEEP ERYTHROCYTES 469 much higher than normal: in the series of animals studied, concentrations ranging from 107 to 310 Hg./100 ml. of red blood cells with an average value of 170,Lg./lOO ml. of red blood cells were observed. Concurrently with high concentrations of free protoporphyrin in the erythrocytes the concentrations of iron in the plasma are abnormally low. 5. Coproporphyrin was not detected in the red blood cells of either normal or vitamin B12-deficient sheep. Electrophoresis on paper indicated that if coproporphyrin is present, the concentration is less than 0 2-0 3 pg./100 ml. of red blood cells.The author is very much indebted to her colleagues Dr L. J. Frahn, for preparing a sample of protoporphyrin IX and for help with the electrophoretic separations, and Mr B. J. Potter, for making available and assisting with the rabbits used in the experiments described. The dimethyl ester of coproporphyrin III was generously supplied by Dr M. R. Lemberg, F.R.S. The guidance of Dr E. A. Cornish in the statistical treatment of the analytical results is gratefully acknowledged.To Mr H. R. Marston, F.R.S., Chief of the Division, the author wishes to express her sincere thanks for suggesting the problem, for making available the experimental sheep from which the blood samples were obtained, and for guidance and encouragement throughout the course of this study.

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“…5. It is encouraging to relate these response surfaces with a classic study by Kolb and Brown [28], suggesting that longer reaction time and lower temperature relatively helps ease the low temperature solvent fractionation. With that, between the studied ranges of this paper, 8 to 24 h of crystallization time and from −15 ºC to 5 ºC of crystallization temperature have been proven efficient to separate USFA.…”

Section: Resultsmentioning

confidence: 69%

Optimization of Low-Temperature Methanol Crystallization for Unsaturated Fatty Acids Separation from Crude Palm Fatty Acids Mixture Using Response Surface Methodology

Bahadi

Yusoff²,

Salimon³

et al. 2019

Asian J. Chem.

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This current work studies the separation of unsaturated fatty acids from crude palm fatty acids mixture by methanol crystallization. Separation conditions of unsaturated fatty acid were optimized through the adoption of the response surface method and the optimal model was developed. The percentages of unsaturated fatty acids recovered under the optimal condition were higher than 95 ± 0.3 % with the yield of product percentage 55.2 ± 0.8 %. The optimized condition comprised of three essential aspects methanol-to-fatty acids ratio of 15:1 (mL:g), crystallization temperature of −15 ºC and crystallization time of 20.8 h, respectively. The unsaturated fatty acids composition isolated from crude palm fatty acids mixture consisted of 76.3 % oleic acid (C18:1), 18.3 % linoleic acid (18:2) and 0.2 % linolenic acid (C18:3). Only 4.9 ± 0.3 % of saturated fatty acids was discovered in the product. The iodine value of separated unsaturated fatty acids had increased from 54.0 ± 0.1 mg/g to 94.4 ± 0.2 mg/g. The results have demonstrated that low-temperature methanol crystallization is very active, low cost, stable and obtainable, and comparatively ease to recover for the separation of unsaturated fatty acids from an oil mixture of fatty acids.

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Low temperature solubilities of fatty acids in selected organic solvents

Cited by 38 publications

References 15 publications

Activation of long chain fatty acids by subcellular fractions of rat liver: III. Effect of ethylenic bond position on acyl‐CoA formation ofcis‐octadecenoates

Activation of long chain fatty acids by subcellular fractions of rat liver: III. Effect of ethylenic bond position on acyl‐CoA formation ofcis‐octadecenoates

South african pilchard oil. 5. The isolation and structure of an eicosapentaenoic acid from South African pilchard oil

Optimization of Low-Temperature Methanol Crystallization for Unsaturated Fatty Acids Separation from Crude Palm Fatty Acids Mixture Using Response Surface Methodology

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