Triglyceride Classes Research Articles

Fatty acid compositions of three lipid classes of Himasthla quissetensis rediae before and after starvation

1.1. The major neutral lipid classes of Himasthla quissetensis rediae are sterols, free fatty acids, triglycerides and sterol esters.2.2. Sixteen fatty acid components of these classes have been resolved using gas-liquid chromatography. The major fatty acid in the sterol ester class is C20:1, in the triglyceride class is C18:1 and in the free fatty acid class is C16:0.3.3. The fatty acid composition of the triglyceride class varies while the composition of the free fatty acid fraction shows a decrease in the relative proportions of C18:1 and shorte chain fatty acids following in vitro starvation. The relative fatty acid composition of the sterol ester class shows no change after starvation.

Fungal lipids. II. Effects of varying concentration of nitrogen in the medium and incubation period on the chemical composition of lipids of Pythium irregulare Buisman.

AbstractEffects of varying the concentration of nitrogen in the medium and the incubation period on the chemical composition of lipids of Pythium irregulare Buisman were studied. In general, with low C/N ratios, the growth of mycelium and the lipid synthesis were found to increase up to the eleventh day of incubation after an initial lag period of five days. Thereafter only slight changes were observed. The fatty acid composition with low C/N ratios showed a considerable variation throughout the growth period. With high C/N ratios, the lipid content continued to increase during the whole period of growth. During this phase of growth, a rapid synthesis of triglycerides along with a marginal increase in the polar fraction was observed.In all the non‐polar lipid classes, oleic and palmitic were the major fatty acid components. Free fatty acid fractions comprised mainly of palmitic, oleic and arachidic acids. In all polar lipid fractions, except phosphatidyl choline and phosphatidic acids, oleic and palmitic were the principal acids. By argentation thin‐layer chromatography, eight mixed triglyceride classes were observed.

Penta-acid triglycerides of Chamaepeuce afra seed oil

1. 1. Earlier work in our laboratory demonstrated that chemical hydrolysis of Chamaepeuce afra (Jacq.) DC. seed oil yields a fatty acid mixture containing 14% (by weight) of (+)- threo-9, 10, 18-trihydroxyoctadec- cis-12-enoic acid and 9% of its saturated analog. The novelty of these acids prompted further work on the glyceride structure of this seed oil. 2. 2. Two classes of unusual triglycerides (85% of the seed oil) have now been isolated and characterized. Each triglyceride class contains one free hydroxyl group as shown by infrared and thin-layer Chromatographic data. 3. 3. Castor bean ( Ricinus communis) lipase hydrolysis of the glycervl ester linkages of the triglycerides yields, in addition to ordinary C 16 and C 18 fatty acids, a trihydroxy acid moiety with two of the tliree hydroxyl groups acylated. In one triglyceride class, these acylating groups are C 12, C 16 and C 18 fatty acids; and in the second, C 16, C 18 and acetic acids. By chromium trioxide oxidation it was shown that the terminal hydroxyl group is acylated. 4. 4. Pancreatic lipase (EC 3.1.1.3) hydrolysis revealed that these acylated trihydroxy acid residues were attached exclusively to the β-position of glycerol and that ordinary C 16 and C 18 acids occupied the α-positions.

Distribution of radioactive glycerol and fatty acids among adipose tissue triglycerides after administration of glucose-U-14C

Adipose lipid obtained from fed rats 15 or 60 min after injection of radioactive glucose was separated into 10 triglyceride classes of differing fatty acid compositions. The distribution among these classes of total and radioactive triglyceride-glycerol was determined and found to be the same. Thus newly synthesized adipose triglycerides resemble in kind and proportion the triglycerides which exist in the tissue. This finding is in accord with the concept that the structures of adipose triglycerides are stable over long periods and that the turnover rate of the several triglyceride species are similar. After administration of radioactive glucose, the specific activity of saturated fatty acids was higher in the more saturated triglyceride species. These data indicate that newly formed saturated acids do not mix completely with all adipose tissue fatty acids available for esterification. Fatty acids derived from plasma triglyceride influenced the composition of newly synthesized adipose tissue triglyceride and thus constitute an important source of adipose tissue lipid.

Structural Analysis of Triglyceride Classes Obtained from Cow's Milk Fat by Fractional Crystallization

Structural Analysis of Triglyceride Classes Obtained from Cow's Milk Fat by Fractional Crystallization

The structure of the glycerides of ergot oils

The oils from sclerotia or from suitable mycelial cultures ofClaviceps purpurea (ergot) contain up to 44% of ricinoleic acid but no free hydroxyl groups. This is due to the presence of, besides normal triglycerides, tetra-acid, penta-acid and hexa-acid triglycerides. These contain respectively one, two and three ricinoleic acids esterified to glycerol, these in turn being acylated at their hydroxy groups with normal long-chain fatty acids. By suitable complementary use of TLC, GLC and lipase hydrolysis techniques, the proportions, compositions and structures of these novel triglyceride classes were determined. Four types of positional specificities in fatty acid combinations could be shown by our procedures. These are discussed and, on the basis of our results, some tentative proposals as to possible biosynthetic mechanisms are advanced.

Intermolecular Specificity of Pancreatic Lipase and the Structural Analysis of Milk Triglycerides

Pancreatic lipase released butyrate and palmitate in equimolar quantities from glyceryl 1-palmitate 2,3-dibutyrate (PBB), an absence of intramolecular specificity. However, when glyceryl 1-myristate 2,3-dioleate (MOO) was mixed with PBB, the latter was hydrolyzed more rapidly, indicating intermolecular specificity. Primary position specificity was maintained during 5-min digestions when glyceryl 2-butyrate 1,3-dipalmitate was the substrate. Data from the pancreatic lipase digestions of milk fat are presented. It is concluded that pancreatic lipase digests some classes of milk triglycerides more rapidly than others.

Abnormalities of circulating lipids: An appraisal of current methods of study

In studies of 537 sets of determinations of serum lipids and lipoproteins in 247 subjects, a high degree of correlation was found among methods which measure beta-lipoprotein by preparative ultracentrifugation, paper electrophoresis or immunoprecipitation. A lower correlation was found between beta-lipoprotein levels and either triglycerides or cholesterol. The lowest correlation was found between the two classes of lipids, triglycerides and cholesterol. In lipoprotein analyses, methods which permit quantitation of alpha- as well as beta-lipoprotein offered more significant information. It appeared important to have information about lipoprotein distribution in addition to obtaining levels of the lipid classes. These data were useful in describing changes occurring with age, weight gain, cessation of ovarian function and in various disease states including hyperlipidemias, thyroid dysfunction and gout. In a study comparing 60 patients with coronary heart disease separated into 34 patients selected for normal cholesterol levels and 26 patients with hypercholesteremia, a similar degree of hyperbeta-lipoproteinemia and hypertriglyceridemia was observed. These data support the importance of these substances in contrast to hypercholesteremia in association with manifest clinical coronary heart disease.