Changes in the lipid and fatty acid composition of hemolymph and ovaries during the reproductive cycle of Labidura riparia

Lipid metabolism was investigated during the reproductive cycle of Labidura riparia (Pallas). The lipid classes and their constitutive fatty acids present in hemolymph and ovaries were measured using thin‐layer chromatography and gas‐liquid chromatography. In the hemolymph, total lipids increase steadily from the previtellogenic period to vitellogenic arrest. These lipids are predominantly diacylglycerols and phospholipids. In the ovaries, total lipids increase during vitellogenesis then decrease during the vitellogenesis arrest period. The major lipids are triacylglycerols, followed by phospholipids. In both hemolymph and ovaries, all lipid classes contained variable proportions of seven main fatty acids: the saturated fatty acids myristic acid (14:0), palmetic acid (16:0), and stearic acid (18:0); the monounsaturated fatty acids palmitoleic acid (16:1) and oleic acid (18:1); and the polyunsaturated fatty acids linoleic acid (18:2) and linolenic acid (18:3). Unsaturated fatty acids predominate throughout the reproductive cycle. The percentage compositions of total and triacylglycerol fatty acids do not change markedly during the reproductive cycle in hemolymph nor in ovaries, with 18:2, 18:1 and 16:0 fatty acids being the major components. However, for diacylglycerols and phospholipids, the proportions of fatty acids vary systematically. For phospholipids during the vitellogenesis period, 18:2 increases considerably whereas other fatty acids decrease; for diacylglycerols, these fatty acids vary in the reverse way.     

Lipid and fatty acid composition of the fat body during the female reproductive cycle of Labidura riparia (Insecta Dermaptera)

During the reproductive cycle of the female Labidura riparia, cytological observations show cyclical modifications of lipid droplets in the periovarian adipocyte. Fat body lipids and their constitutive fatty acids are analyzed. The lipids are predominantly triacylglycerols, which increase after adult ecdysis during vitellogenic and non-vitellogenic periods. Small amounts of diacylglycerols and phospholipids are found. Diacylglycerols increase during vitellogenesis and decrease during the non-vitellogenic period. Cytological modifications of lipid droplets are probably related to diacylglycerol fluctuations. Gas-liquid chromatography of fatty acid methyl esters shows oleic acid to be the predominant fatty acid in total lipids and triacylglycerols; unsaturated acids are approximately twice as abundant as saturated acids all along the reproductive cycle. Fatty acid composition of diacylglycerols and phospholipids differs from triacylglycerols and total lipids composition. Palmitic, stearic, oleic and linoleic acids represent the major fatty acids; their relative amounts vary during the different periods of the reproductive cycle. The correlations between fat body lipid changes and ovarian development were discussed and compared with observations made on other insect species. Accepted: 23 April 1997     

Physiological studies on Phymatotrichum omnivorum VI. Lipid composition of mycelium and sclerotia

The lipid composition of the mycelium and sclerotia ofPhymatotrichum omnivorum was compared. The lipids of the mycelium contained 47.9 % polar lipids as compared to 21.4 % in the sclerotia. Sterols represented 10 % of the lipids in sclerotia as contrasted to 3.6 % of the mycelium. More monoglycerides (17.5 %) were detected in the sclerotia as compared to the mycelium (1.6 %). Fatty acid analysis indicated that linoleic acid was the predominant fatty acid in the total fatty acids fraction in both the mycelium and the sclerotia. Palmitic acid was the major free fatty acid in the mycelium, whereas myristic acid was the predominant free fatty acid in the sclerotia. In the fatty acids of the diglycerides of sclerotia, palmitic acid represented 71 % of that fraction, as compared to 6.6 % of the fatty acids of the diglycerides in the mycelium. The major fatty acid in the diglycerides of the mycelium was oleic acid.     

Production of volatiles by degradation of lipids during manufacture of black tea

During manufacture of black tea, lipids are degraded to volatile constituents. Cis-3-hexenal was present in appreciable amounts in the various parts of fresh shoots and decreased in the second leaves during manufacture. There was a simultaneous increase in trans-2-hexenal. Linalol and methyl salicylate also increased appreciably during rolling and fermentation. Most of the volatiles were lost during the firing process. The above trend was borne out by the ‘potential’ of the leaves for the production of volatiles as indicated by the increased amounts of volatiles produced by homogenizing the tissue in water against controls homogenized in 0.1 N acid. The C₆-aldehydes present in the headspace of withered shoots increased significantly following mechanical damage. The major fatty acids of the lipids in the various parts of the shoots were linolenic, linoleic, palmitic, oleic and stearic acids. The ratio of linoleic to linolenic acid in the stems was much higher than that of the leaves or buds and this was reflected in its higher 'potential for formation of hexanal. During withering and rolling of the second leaves, the unsaturated fatty acids showed substantial losses compared with the saturated acids. It is suggested that the enzymic breakdown of membrane lipids initiate the formation of volatile carbonyl compounds which are partly responsible for the flavour of black tea.     

Lipids and lipid metabolism in the brown alga, Fucus serratus

The lipids of the brown alga Fucus serratus were isolated, identified and quantified. The major acyl lipids were the three glycosylglycerides, diacylgalactosylglycerol, diacyldigalactosylglycerol and diacylsulphoquinovosylglycerol. These represent over 70% of the total acyl lipids. The fatty acid compositions of the major lipids were examined and most showed rather distinctive fatty acid contents. For example, diacylgalactosylglycerol was enriched in n-3 polyunsaturated fatty acids while phosphatidylcholine and phosphatidylethanolamine had very high levels of arachidonate. Phosphatidylglycerol contained the unusual trans-Δ3-hexadecenoic acid. The labelling of lipids and fatty acids from [¹⁴C]acetate was examined and the distribution of label between individual components as a function of the incubation period and in algae collected at different times of the year is reported. Algae collected in the winter incorporated much more radioactivity into non-esterified fatty acids when compared to algae collected in the summer. All algae could label myristate, palmitate, stearate and oleate at high rates. Longer incubation times allowed the labelling of polyunsaturated fatty acids such as linoleic acid.     

Lipid composition of thermophilic moulds Acremonium alabamensis and Thermomucor indicae-seudaticae

The total lipid content of Acremonium alabamensis and Thermomucor indicae-seudaticae ranged 2.6–7.3 and 8.5–13.0% of dry mycelium, respectively during development. Neutral lipid fraction increased during growth while polar and phospholipids declined. Both moulds contained palmitic, oleic, linoleic and palmitoleic acids as major fatty acid components in lipids. Degree of unsaturation of lipids of A. alabamensis was greater than that of T. indicae-seudaticae. Neutral lipids were more unsaturated than the polar lipids. The ratio of unsaturation index of polar lipids to neutral lipids was either one or less than one. The principal phospholipids of these moulds were phosphatidyl choline, phosphatidyl ethanolamine and phosphatidic acid. However, phosphatidic acid was not found in very high amounts as observed in Humicola grisea var. thermoidea.     

THE EFFECT OF DIFFERENT DIETARY LEVELS OF ESSENTIAL FATTY ACIDS ON LIPIDS OF RAT CEREBRUM DURING MATURATION1

Abstract— Three dietary levels of essential fatty acids, 30, 0-75 and 007 calorie-%, with a linoleic: linolenic acid ratio of 4:1, were fed to rats for two generations. In the third generation the weight of the cerebrum and the concentration of its lipids and the fatty acid composition of phosphoglycerides were determined from term to 120 days of age. The cerebral weights and the concentrations of phospholipids, cholesterol and cerebrosides differed only slightly between the three dietary groups. The accretion of fatty acids of the linoleic acid series was independent of the dietary essential fatty acid level while the accretion of fatty acids of the linolenic acid series was markedly reduced in the groups with low essential fatty acid supply. The sum of the total polyunsaturated fatty acids in ethanolamine phosphoglycerides differed only slightly between the groups. The proportion of the major polyunsaturated fatty acid of the linoleic acid series was equal between the groups while that of 22:6 (n-3) was much lower in the groups fed 007 calorie % essential fatty acids. In these latter groups the relative concentrations of 22:5 (n-6), 20:3 (n-9) and 22:3 (n-9) were increased. The differences in the fatty acid composition were dependent on the age of the rats. They were largest in newborn rats and diminished with age after weaning.     

Metabolism of fatty acids by bovine spermatozoa

The incorporation of (14)C-labelled myristic, palmitic, stearic, oleic and linoleic acids in vitro into the lipids of bovine spermatozoa was measured at intervals from 2min to 2h. All acids were rapidly incorporated into diglycerides, myristic acid being metabolized to the greatest extent. Whereas the low incorporation of acids into total phospholipids reflected the relative stability of the major phospholipid fractions in sperm, the minor phospholipids, particularly phosphatidylinositol, showed comparatively high metabolic activity. Although, in general, saturated acids were incorporated more actively than unsaturated substrates, stearic acid was poorly incorporated into all lipids except phosphatidylinositol. In regard to fatty acid composition of sperm lipids it was notable that diglycerides contained myristic acid as the major component, and this acid was also a prominent moiety of phosphatidylinositol. Docosahexaenoic acid was the principal fatty acid of the major phospholipid classes. These findings have been discussed in relation to the role of lipids in the metabolism of spermatozoa.     

The effect of lipids and temperature on the physiology and growth ofVolvariella volvacea

Vegetable oils promoted mycelial growth ofVolvariella volvacea. Ethyl esters of major components of saponified fatty acids (palmitic, stearic, oleic and linoleic acid) from vegetable oils were stimulatory. The stimulatory effect of these fatty acids varied with concentration and degree of unsaturation; relatively high concentrations being inhibitory. Mycelial growth appears to be promoted by low concentrations of fatty acids. Supplementation of growth medium with sunflower oil altered membrane permeability and this resulted in an increased uptake of glucose. The total mycelial lipids accounted for only 30% of consumed lipids, the remainder being metabolized. The failure of the fungus to adjust the degree of unsaturation in membrane lipids when it was transferred to 0°C may partially explain its susceptibility to chilling injury.     

Genomic and biochemical analysis of lipid biosynthesis in the unicellular rhodophyte Cyanidioschyzon merolae: lack of a plastidic desaturation pathway results in the coupled pathway of galactolipid synthesis

The acyl lipids making up the plastid membranes in plants and algae are highly enriched in polyunsaturated fatty acids and are synthesized by two distinct pathways, known as the prokaryotic and eukaryotic pathways, which are located within the plastids and the endoplasmic reticulum, respectively. Here we report the results of biochemical as well as genomic analyses of lipids and fatty acids in the unicellular rhodophyte Cyanidioschyzon merolae. All of the glycerolipids usually found in photosynthetic algae were found, such as mono- and digalactosyl diacylglycerol, sulfolipid, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol. However, the fatty acid composition was extremely simple. Only palmitic, stearic, oleic, and linoleic acids were found as major acids. In addition, 3-trans-hexadecanoic acid was found as a very minor component in phosphatidylglycerol. Unlike the case for most other photosynthetic eukaryotes, polyenoic fatty acids having three or more double bonds were not detected. These results suggest that polyunsaturated fatty acids are not necessary for photosynthesis in eukaryotes. Genomic analysis suggested that C. merolae lacks acyl lipid desaturases of cyanobacterial origin as well as stearoyl acyl carrier protein desaturase, both of which are major desaturases in plants and green algae. The results of labeling experiments with radioactive acetate showed that the desaturation leading to linoleic acid synthesis occurs on phosphatidylcholine located outside the plastids. Monogalactosyl diacylglycerol is therefore synthesized by the coupled pathway, using plastid-derived palmitic acid and endoplasmic reticulum-derived linoleic acid. These results highlight essential differences in lipid biosynthetic pathways between the red algae and the green lineage, which includes plants and green algae.     

The lipid composition of Acer pseudoplatanus cells grown in culture

Cells of Acer pseudoplatanus were grown in batch suspension culture for 22 days. The cultures were initiated at high cell density of 2 × 10⁵ cells per ml of culture. Growth was characterised by a short lag phase, an exponential phase of rapid cell division and growth, and finally a stationary phase. Quantitative but not qualitative changes were observed in total lipid content, fatty acids and phospholipids at different stages of growth. Total lipids, phospholipids and fatty acids showed maximum concentrations in 12 day old cells. The major phospholipids isolated were phosphatidylcholine and phosphatidylethanolamine with minor amounts of phosphatidic acid and lysophosphatides. Other lipid components present were mono- and digalactosyl diglycerides, cerebrosides, sterol glucosides, free fatty acids and esterified sterol glucosides. The major constituent fatty acids were myristic acid (14:0), palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2) and linolenic acid (18:3). During exponential cell growth the proportion of 16:0, 18:2 and 18:3 constituted nearly 90% of the total fatty acids. Triglycerides were the major repository of myristic acid (14:0) with substantial amounts of palmitic acid (16:0), whereas phospholipids contained 16:0, 18:2 and 18:3 in high amounts.     

FATTY ACIDS OF CUPHEA (LYTHRACEAE) SEED LIPIDS AND THEIR SYSTEMATIC SIGNIFICANCE

Fatty acid analyses of seed lipids in 46 species of Cuphea are presented, representing the first major survey of a molecular nature for the family. A remarkable diversity in composition is found, with seeds containing high amounts of several medium chain fatty acids. Lauric acid (12:0) predominates in 43% of the species studied, constituting 50–74% of the total fatty acid content. Capric acid (10:0) is the dominant fatty acid in 32% of the species, comprising as much as 87% of the total acid content. Caprylic acid (8:0) predominates in one section of the genus. The emphasis on production of fatty acids with carbon chain lengths of 12, ten, and eight carbon atoms is unique among plant genera studied to date. Among seven of the nine sections studied, one pattern of fatty acid composition predominates. Two sections have no characteristic pattern, supporting other evidence of their polyphyletic origin. The most significant systematic contribution is made by comparison of the predominate fatty acid components in the seed lipids. When used in conjunction with floral morphology, pollen studies, and chromosome number, it provides an important new basis on which to draw inferences of evolution and clarify present relationships within the genus. Additionally, a trend from the longer-chained, unsaturated linoleic acid (18:2) as a major lipid component to shorter-chained saturated capric and caprylic acids is correlated with increasing floral specialization. It is suggested that mutations in regulatory genes have occurred which cause fatty acid production in seeds to cease at progressively earlier stages, resulting in accumulation of large amounts of single fatty acids of progressively shorter carbon chain lengths.     

Isolation of biochemical mutants using haploid mesophyll protosplasts of Hyoscyamus muticus

The question of whether membrane expansion, which is caused by anesthetics in animal systems, alters the lipid composition of plant cell membranes was investigated. We have measured the effects of several anesthetics on the relative amounts of the principal fatty acids from the polar lipids of barley (Hordeum vulgare L.) root membranes. Procaine, dibucaine, tetracaine, chloroform and, to a lesser degree, methanol increased the proportions of palmitic, stearic and oleic acids and decreased the proportions of linoleic and linolenic acids. Ethanol had no significant effect. Total amounts of the fatty acids from the polar lipids of roots in procaine solution decreased markedly so that all of the acids decreased in amount. The anesthetic was effective as soon as the roots were introduced to the solution and the changes progressed at constant rates for 6 h. Only the polar membrane lipids were altered; other lipids were not affected. Increased hydrostatic pressure of about 1.0 MPa largely prevented the anesthetic effects, including the decrease in the total amounts of the fatty acids. Hydrostatic pressure as high as 2 MPa had no effect per se on the membrane lipid composition. These results indicate that anesthetics cause expansion of the root membranes which results in the lipid changes. That a compositional change in the membrane lipids involves a conformational change such as expansion is an indication of the nature of the link between changes in the membrane lipids and changes in function of areas where hydrophilic ions permeate.Abbreviations 16:0 palmitic acid - 18:0 stearic acid - 18:1 oleic acid - 18:2 linoleic acid - 18:3 linolenic acid     

Isolation and composition of the carotenoid-containing oil droplets from cone photoreceptors.

A procedure for isolating the carotenoid-containing oil droplets of cone retinal photoreceptors of Gallus domesticus is described. The oil droplets, composed almost entirely of neutral lipids and carotenoids, have been separated into ten chromatographic components. Similar separations have been carried out on the total retinal neutral lipids for comparison. The neutral lipids represented 26.1% of the total retinal lipid. Cholesterol, cholesterol ester, mono-, di- and triacylglycerols represented 92.6% of the total neutral lipid. Each of these and other minor neutral lipid components were also present in the lipids extracted from the isolated oil droplets in correspondingly similar concentrations. However, the concentrations of carotenoids were greatly enriched in the neutral lipids of the oil droplets. Each of the major fatty acyl-containing neutral lipids from the chromatography of oil droplet lipids is greatly enriched in polyunsaturated fatty acids when compared with the corresponding component from the total neutral lipid chromatography. In the acylglycerols and free fatty acid fraction from the oil droplets, linoleic and arachidonic acid together represented 52-83% of the total polyunsaturated fatty acids present. The remainder was generally distributed about equally among six other acids. Except for the diacylglycerol fraction, linoleic acid was usually the most enriched acid in a specific oil droplet fraction when compared with any other polyunsaturated fatty acids. A similar pattern of polyunsaturated fatty acid enrichment observed in the fatty acids of the outer segment phospholipids relative to the corresponding total phospholipid fractions of this cone rich retina (Johnston, D. and Hudson, R.A. (1974) Biochim. Biophys. Acta 369, 269) suggest possible metabolic relationships between the oil droplet neutral lipids and the outer segment membrane phospholipids of the cone photoreceptors. A mechanism for the accumulation of the carotenoids in the oil droplets is also discussed.     

Kinetic profile of the cellular lipid composition in an oleaginous Yarrowia lipolytica capable of producing a cocoa-butter substitute from industrial fats

Cell growth, lipid accumulation and cellular lipid composition of Yarrowia lipolytica growing on mixtures of industrial fats containing stearic, oleic, linoleic and palmitic acid have been studied. During growth, the strain incorporated oleic and linoleic acids more rapidly than the saturated fatty acids. Relatively high lipid accumulation (up to 0.44 g of lipids per g of dry matter) was observed when stearic acid was included in the culture medium. In contrast, substrates rich in oleic acid did not favor cellular lipid accumulation. The accumulated lipids, mainly composed of triacylglycerols (45-55% w/w), demonstrated a different total fatty acid composition compared with that of the substrate; in all cases, the microorganism showed the unusual capacity to increase its cellular stearic acid level, even if this fatty acid was not found in high concentrations in the substrate. This permitted the synthesis of interesting lipid profiles with high percentages of stearic acid and non-negligible percentages of palmitic and oleic acid, with a composition resembling that of cocoa-butter.     

Lipid composition of housefly microsomes

The lipid composition of microsomes isolated from whole-body preparations of a diazinon-resistant strain of the housefly (Musca domestica L.) was determined. When calculated on a mg% basis housefly microsomes are composed of 47% neutral lipids and 53% phospholipids. The free fatty acids compose the major group of compounds among neutral lipids (60%) and the major phospholipid is phosphatidylethanolamine (47.6%). The molar cholesterol/phospholipid ratio is 0.14, ca. twofold higher than the ratio found in mammalian liver microsomes. Fatty acid composition of housefly microsomes is notable only in that there is no uniform distribution of fatty acid moieties throughout the various classes of lipids, except for linoleic acid (18:2), which accounted for 9.2-12.6% of the neutral lipids. Eighty percent of the fatty acid moieties of phosphatidylserine (+ phosphatidylinositol) were unsaturated. The highest percentage of saturated fatty acid moieties (64.26%) was found in lysophosphatidylethanolamine. Palmitoleic acid (16:1), the major fatty acid found in higher dipterans, ranged from 13.51% in lysophosphatidylethanolamine to 37.45% in the free fatty acids. One prostaglandin (PGF_1d) and leukotriene B₄ were detected in the microsomal lipids at concentrations of 59.7 and 716 pg/200 mg of protein, respectively.     

Effect of amylose content on the lipids of mature rice grain

Most of the nonstarch lipids in brown rice (Oryza sativa) of three rices differing in amylose content were contributed by bran, germ, polish and subaleurone layer. Nonstarch lipids consisted of 82–91% neutral lipids (of which 73–82% were triglycerides), 7–10% phospholipids and 2–8% glycolipids. Linoleic, oleic and palmitic acids were the major fatty acids. Nonwaxy (24 and 29% amylose) milled rice had proportionally more starch lipids and less nonstarch lipids than waxy (2% amylose) milled rice. Starch lipids were mainly lysophosphatidyl choline, lysophosphatidyl ethanolamine and free fatty acids. The major fatty acids were palmitic and linoleic acids, followed by oleic acid.     

Comparison of the Effects of Orally Administered Linoleic Acid,and Its Hydroperoxides and Secondary Autoxidation Products on Hepatic Lipid Metabolism in Rats

Linoleic acid, and its hydroperoxides and secondary autoxidation products were orally administered to rats (400 mg/rat). Their effects on hepatic lipid metabolism were examined. Linoleic acid reduced the activities of de novo synthesis of fatty acids and acetyl-CoA carboxylase. It decreased the CoASH level and caused the accumulation of long-chain acyl-CoA. Hydroperoxides changed the compositions of unsaturated fatty acids in the hepatic lipids and lowered the content of neutral lipids. Secondary products stimulated carnitine palmitoyltransferase and decreased the content of neutral lipids. They reduced the activities of de novo synthesis of fatty acids and acetyl-CoA carboxylase, and the levels of CoASH and acetyl-CoA. Thus, the effect of secondary products was apparently different from those of linoleic acid and its hydroperoxides.     

Dependence of the fatty acid composition of the lipids in fungi of the genus Penicillium on their natural habitat conditions

The fatty acid composition of lipids was studied in Penicillium fungi growing in different habitats. Saturated fatty acids were represented by lauric, margaric, stearic and palmitic acids (the latter prevailed-- 18%-26%). Unsaturated monoene fatty acids were represented by acids from C16:1 to C18:1, diene and triene fatty acids by linoleic and linolenic acids. The predominance of linoleic acid was not found in all cultures of the genus. Changes in the fatty acid composition of lipids may be attributed to different ecological habitats of the Penicillium genus species.     

Lipid degradation during manufacture of black tea

About 85% of the fatty acids liberated during the manufacture of black tea can be attributed to autolysis of 4 major polar lipid classes in tea leaf tissue, phosphatidylcholine, monogalactosyldiglyceride, digalactosyldiglyceride and phosphatidylethanolamine. Linolenic, linoleic and palmitic acids are the principal fatty acids released from these lipids and they all undergo further degradation. Linolenic acid (60% of fatty acids released) is derived mainly from galactolipids and thus the upper limit of release is dependent on the chloroplast maturity and content of the leaf tissues. Lipid breakdown is complete after 2 hr fermentation and, as there appears to be no accumulation of long chain fatty acid intermediates, it is probable that volatile production has also ceased at this time.