Lipids of a T Strain of Mycoplasma

Cholesterol, free fatty acids, and phosphatidic acid are the predominant lipids of a T strain of Mycoplasma. The remaining neutral lipids are composed of cholesteryl esters, triglycerides, and diglycerides. Three glucose-containing glycolipids are present in trace amounts. In addition to phosphatidic acid, the phospholipids are comprised of phosphatidyl glycerol, diphosphatidyl glycerol, and phosphatidyl ethanolamine. Another polar lipid was found to be ninhydrin-positive and phosphate-free. It appears to be a diamino hydroxy compound containing adjacent fatty acid ester and N-acyl groups.     

Effect of light on lipid composition of Ricinus cell cultures

The changes of lipid composition were determined in callus cultures from Ricinus communis endosperm upon transfer from darkness into light. Culture in light induced chlorophyll synthesis and formation of differentiated chloroplasts. In light-grown cultures the major lipid classes were phospho- and glycolipids, dark-grown cultures were rich in triacylglycerol. The major fatty acids were linolenic acid and palmitic acid in both cultures. In the green cultures linolenic acid was predominantly esterified in glycolipids whereas in the dark-grown cultures this fatty acid was the major component of phospholipids. Ricinoleic acid was not found.Abbreviations PC phosphatidylcholine - PE phosphatidylethanolamine - MGD monogalactosyldigylceride - DGD digalactosyldiglyceride - SE steryl esters - NL neutral lipids     

Cyclic glycolipids from glandular trichome exudates of Cerastium glomeratum

Fourteen cyclic glycolipids, named glomerasides A–N, have been isolated from the glandular trichome exudate of Cerastium glomeratum (Caryophyllaceae). Their structures were determined by spectroscopic analysis of the glycolipids, as well as by application of the Ohrui–Akasaka method to the fatty acid methyl esters derived from the glycolipids and GCMS studies of trimethylsilyl ether derivatives of the methyl esters. The various glomerasides have a glycosidic linkage between the anomeric hydroxy group of the glucose and the C-11, C-10 or C-9 positions of the docosanoyl moiety. They also contained an ester linkage between the C-6 hydroxy group of the glucose ring and the carboxyl group of the oxygenated fatty acid to form their macrocyclic structures. The glucose moiety was optionally acetylated and/or malonylated at the C-2 or C-3 hydroxy groups. Among these compounds, the 1,6′-cyclic ester of 11(R)-(2-O-acetyl-β-d-glucopyranosyloxy)docosanoic acid (glomeraside D) was the most abundant (25%).     

6-acyl galactosyl ceramides of pig brain: structure and fatty acid composition

Two glycolipids were isolated from pig brain and were shown to be the fatty acid esters of kerasin and cerebron in which the second fatty acid moiety is attached to the 6-position of the galactose. The point of attachment was shown in two ways: by permethylation and by cleavage with periodate. Methanolysis of the permethylated cerebroside esters yielded O-methyl sphingosines, methyl esters of nonhydroxy or 2-methoxy acids, and methyl 2,3,4-trimethyl galactoside. Cleavage of the cerebron ester with periodate, followed by treatment with sodium borohydride and dilute HCl, yielded ceramide plus 1-monoglyceride. The ester-linked fatty acids were primarily 16:0, 18:0, and 18:1, while the amide-linked fatty acids showed the wide assortment of chain lengths typical of brain cerebrosides. The methylation step, with silver oxide and methyl iodide, yielded two derivatives with the cerebroside esters, but the structural explanation for the difference was not elucidated. The galactose in the cerebron ester was shown to exist in the beta-pyranoside form.     

Changes in monogalactosyl diacylglycerols, alkylgalactolipids and cerebroside fatty acid esters in maturing rat brain measured by high-performance liquid chromatography

A newly developed high-performance liquid chromatography method was used to measure four nonpolar glycolipids in developing rat brain. The accumulation patterns of nonhydroxy- and hydroxycerebroside fatty acid esters were similar to those of myelin cerebrosides. In contrast, both monogalactosyl diacylglycerol and alkylgalactolipids reached maximal levels at the early stages of myelination.     

Glycolipids of peripheral nerve: isolation and characterization of glycolipids from rabbit sciatic nerve

Besides cerebreside and sulfatide four other glycolipids were isolated from rabbit sciatic nerve and analyzed by chemical and chromatographic methods. Three of the glycolipids were shown to be fatty acid esters of cerebroside; the fourth was characterized as diacyl glycerol galactoside and its alkyl ether analog. In the ester linkage mainly unsubstituted acids with chain length C(16) to C(18) were present. Both hydroxy and unsubstituted acids were found in amide linkage. They varied in chain length from C(16) to C(24) and were typical of cerebrosides. The long-chain base fraction contained sphingosine and dihydrosphingosine as the main components.     

Structural determination of the polar glycoglycerolipids from thermophilic bacteria Meiothermus taiwanensis.

The polar glycolipids were isolated from the thermophilic bacteria Meiothermus taiwanensis ATCC BAA-400 by ethanol extraction and purified by Sephadex LH-20 and silica gel column chromatography. The fatty acid composition of O-acyl groups in the glycolipids was obtained by gas chromatography mass spectroscopy analysis on their methyl esters derived from methanolysis and was made mainly of C(15:0) (34.0%) and C(17:0) (42.3%) fatty acids, with the majority as branched fatty acids (over 80%). Removal of O-acyl groups under mild basic conditions provided two glycolipids, which differ only in N-acyl substitution on a hexosamine. Electrospray mass spectroscopy analysis revealed that one has a C(17:0) N-acyl group and the other hydroxy C(17:0) in a ratio of about 1 : 3.5. Furthermore, complete de-lipidation with strong base followed by selective N-acetylation resulted in a homogeneous tetraglycosyl glycerol. The linkages and configurations of the carbohydrate moiety were then elucidated by MS and various NMR analyses. Thus, the major glycolipid from M. taiwanensis ATCC BAA-400 was determined with the following structure: alpha-Galp(1-6)-beta-Galp(1-6)-beta-GalNAcyl(1,2)-alpha-Glc(1,1)-Gro diester, where N-acyl is C(17:0) or hydroxy C(17:0) fatty acid and the glycerol esters were mainly iso- and anteisobranched C(15:0) and C(17:0).     

Lipids of Leaves and Seeds

The lipid components of the chlorophyll lipoproteins isolated from the leaves of Cayratia japonica, Vicia sativa, and Artemisia princeps were separated and identified by column, thin-layer, and paper chromatographies. The lipids were mainly composed of carotenoids, quinones including plastoquinone, sterols and their esters, di- and monoglycerides, free fatty acids, chlorophylls and their degradation products, glycolipids including plant sulfolipids, and phospholipids, in which the glycolipids were predominant. The fatty acid composition was characteristic depending on each separated lipid component. Comparison of the lipid distributions was made between whole leaf and chlorophyll lipoprotein, and also between chlorophyll lipoproteins from young leaves and from full-grown leaves.     

Sophorose lipid production from lipidic precursors: Predictive evaluation of industrial substrates

Summary Sophorose lipids stand out as biosurfactants with a wide potential for industrial application and which can be produced in good yield from glucose and a lipidic cosubstrate.Candida bombicola CBS 6009 (ATCC 22214) was used in the present study. The influence of the lipidic cosubstrate on various aspects of production performance of these glycolipids (final concentration, yield) and on product composition (in particular, the structure of the hydroxy fatty acid vegetable and animal oils, markedly influenced product composition. In terms of production performance, the best substrates were oils or esters rich in C18:0 and C18:1 fatty acids. Optimal overall performance was obtained with esters (340 g L^–1 sophorose lipids with rapeseed esters). Conclusions drawn from the results allow predictive evaluation of lipidic industrial substrates.     

Lipid profiles of Aspergillus niger and its unsaturated fatty acid auxotroph, UFA2

A comparative study of the mycelial lipid composition of a wild strain (V35) and one unsaturated fatty acid auxotroph (UFA2) of Aspergillus niger has been performed. The lipid composition of both strains are qualitatively the same but quantitatively different. All the strains contain the following phospholipids: cardiolipin, phosphatidylethanolamine, phosphatidylcholine, lysophosphatidylethanolamine, lysophosphatidylcholine, and phosphatidylserine; and triglycerides, diglycerides, monoglycerides, ergosterol, and sterol esters as the neutral lipids; mono- and di-galactosyl diglyceride as the major glycolipids along with small amounts of the corresponding mannose analogs. Phosphatidylethanolamine and phosphatidylcholine constitute the bulk of the phospholipids. The mutant (UFA2) contains a higher level of glycerides and lower levels of sterol (both free and esterified form), phospholipids, and glycolipids than the wild type. Aspergillus niger contains C16 to C18 saturated and unsaturated fatty acids. Small amounts of long-chain (C20 to C24) and short-chain (C10 to C14) saturated and unsaturated acids are also present. Linoleic, oleic, and palmitic are the major acids, stearic and linolenic acids being minor ones. UFA2 grows only in the presence of unsaturated fatty acid (C16 or C18) and accumulates a higher concentration of supplemented acid which influences its fatty acid profile.     

Regio- and stereoselective enzymatic esterification of glycerol and its derivatives.

A methodology for regio- and stereoselective preparation of acyl glycerol derivatives is presented. It offers easy access to specific 1,2-, 1,3-diglycerides and triglycerides as well as alkyl glycerol esters, phospholipids and glycolipids. These compounds are prepared by esterification of the corresponding glycerol derivatives such as 2-monoglycerides, alkyl glycerols, glyceryl glycosides, glyceryl phosphate esters, or unsubstituted glycerol. The regio- and stereoselectivity in the esterification is achieved by using fatty acid anhydrides and an enzymatic catalyst, 1,3-specific lipase. NMR methods for determining the regio- and stereoselectivity of esterification are discussed.     

Lipids of Leaves and Seeds

The lipids in rice bran lipoprotein were separated and their qualitative and quantitative analyses were carried out by column, thin-layer, gas-liquid, and paper chromatographic methods. More than twenty lipid components were detected, of which triglycerides and glycolipids were found to be the major components. Considerable amounts of free fatty acids were also found. The glycolipids were composed of mono- and digalactosyl glycerides, sterol glycosides and their esters, probably phytocerebrosides, and other unknown glycolipids. Phospholipids were present as the minor components of rice bran lipoprotein. The presence of oryzanols in the lipoprotein was observed.     

Thehalose mycolates from Nocardia asteroides,Nocardia farcinica,Gordona lentifragmenta and Gordona bronchialis

Isolation of glycolipids from Nocardia asteroides, N. farcinica, Gordona lentifragmenta and G. bronchialis, by column chromatography of lipid extracts on a 50% (w/w) mixture of silicic acid and silica gel H, is described. The isolated materials were partially characterized by infrared spectroscopy, optical rotation and refractive index measurements, and by identifying the products of alkaline hydrolysis. Analytical studies showed that the glycolipids released only trehalose in the aqueous phase while mycolic acids were the constituent fatty acids identified.The isolated lipids are trehalose esters in which the trehalose molecule is esterified with mycolic acids.     

Fatty acid, isoprenoid quinone and polar lipid composition in the classification of Renibacterium salmoninarum

Twenty-one strains of Renibacterium salmoninarum were degraded by acid methanolysis and the non-hydroxylated fatty acid esters released examined by thin-layer and gas chromatography. The fatty acid profiles were composed almost exclusively of methyl-branched fatty acids with 12-methyltetradecanoic ( anteiso -C₁₅), 13-methyltetradecanoic ( iso -C₁₅) and 14-methylhexadecanoic ( anteiso -C₁₇) as major components. Polar lipids of the test strains were examined by two-dimensional thin-layer chromatography. All of the organisms possessed very characteristic polar lipid patterns consisting of diphosphatidylglycerol, two major and six or seven minor glycolipids, and two unidentified minor phospholipids. In all cases the major menaquinone components consisted of unsaturated menaquinones with nine isoprene units. The lipid data support the integrity of the genus Renibacterium and can be used to separate it from Corynebacterium and from coryneform bacteria which also contain lysine in the wall peptidoglycan.     

Fatty acids of glycosphingolipids from pig blood fractions

Four glycolipids have been isolated from three fractions of pig blood. The glycolipids were presumably cerebroside, diglycosyl ceramide, triglycosyl ceramide, and globoside. The blood fractions were erythrocytes and plasma high and low density lipoproteins. Fatty acid distributions were determined for each glycolipid as a means to assist in identifying relationships among the several glycolipids. Normal fatty acids predominated in all glycolipids except the globosides from erythrocytes in which the amount of hydroxy acids was slightly greater than the amount of normal acids. Hydroxy acids appeared to be present in all the glycolipids, but the concentration was very low in cerebrosides isolated from high density lipoproteins and erythrocytes, and in diglycosyl ceramide and globoside of the low density lipoproteins. In general, the average fatty acid chain length increased from cerebroside to globoside. This was most apparent in erythrocytes and also greater for normal acids than for hydroxy acids. Fatty acid distributions of erythrocyte glycolipids had sufficient variation to make a metabolic relationship by simple addition of a hexose appear doubtful. While the fatty acid distributions found in plasma lipoproteins were more similar, some means of acyl group selection is probably present for either the synthesis or degradation of these glycolipids.     

Fatty acid,polar lipid and wall amino acid composition of Gardnerella vaginalis

Representative strains of Gardnerella vaginalis were degraded using both an alkaline and an acid methanolysis and the fatty acid methyl esters released examined by thin-layer and gas chromatography. The profiles obtained were both qualitatively and quantitatively similar and were comprised of straight chain saturated and unsaturated non-hydroxylated fatty acids with hexadecanoic acid (16:0) and octadecenoic acid (18:1) the major components. All of the strains contained very characteristic polar lipid patterns consisting of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, five partially identified glycolipids and an uncharacterised phospholipid. Analyses of wall amino acid preparations using gas chromatography showed that Gardnerella vaginalis strains contain major amounts of alanine, glycine, glutamic acid and lysine. The chemical data support the integrity of the genus Gardnerella.     

Biosynthesis of unnatural glycolipids possessing diyne moiety in the acyl chain in the green sulfur photosynthetic bacterium Chlorobaculum tepidum grown by supplementation of 10,12-heptadecadiynic acid

Unnatural glycolipids possessing the diyne moiety in their acyl groups were successfully biosynthesized in the green sulfur photosynthetic bacterium Chlorobaculum (Cba.) tepidum by cultivation with supplementation of 10,12-heptadecadiynic acid. Monogalactosyldiacylglycerol (MGDG) and rhamnosylgalactosyldiacylglycerol (RGDG) esterified with one 10,12-heptadecadiynic acid were primarily formed in the cells, and small amounts of glycolipids esterified with the two unnatural fatty acids can also be detected. The relative ratio of these unnatural glycolipids occupied in the total glycolipids was estimated to be 49% based on HPLC analysis using a evaporative light scattering detector. These results indicate that the acyl groups in glycolipids, which play important roles in the formation of extramembranous antenna complexes called chlorosomes, can be modified in vivo by cultivation of green sulfur photosynthetic bacteria with exogenous synthetic fatty acids. Visible absorption and circular dichroism spectra of Cba. tepidum containing the unnatural glycolipids demonstrated the formation of chlorosomes, indicating that the unnatural glycolipids in this study did not interfere with the biogenesis of chlorosomes.     

Novel type-specific lipooligosaccharides from Mycobacterium tuberculosis

Mycobacterium tuberculosis (strain Canetti) is characterized by the presence of two novel glycolipids of the alkali-labile, trehalose-containing lipooligosaccharide class. Their structures were established by permethylation, partial acid hydrolysis, infrared and high-field NMR spectroscopy, and electron-impact and fast atom bombardment mass spectrometry of the native glycolipids and hydrolysis products. The trehalose substituent is unique in that it is methylated at the 6'-position. The structure of the simpler of the two glycolipids is 2-O-Me-alpha-L-Fucp(1----3)-beta-D-Glcp(1----3)-2-O-Me- alpha-L-Rhap(1----3)-2-O-Me-alpha-L- Rhap(1----3)-beta-D-Glcp(1----3)-4-O-Me-alpha-L-Rhap(1----3) -6-O-Me-alpha-D- Glc. Further glycosylation of the octaglycosyl unit of this nonantigenic glycolipid by an incompletely defined N-acyl derivative of a 4-amino-4,6-dideoxy-Galp residue results in the second, highly antigenic nonasaccharide-containing glycolipid. Application of two-dimensional proton correlation spectroscopy demonstrated that the fatty acyl substituents are located on the 2,3,6 and 3,4,6 hydroxyl groups of the terminal glucosyl unit in the proportions of 2:3. Gas chromatography/mass spectrometry and optical rotation measurement allowed identification of the fatty acyl esters as primarily 2L-, 4L-dimethylhexadecanoate, 2L-,4L-,6L-,8L-tetramethyloctadecanoate, and 2-methyl-3-hydroxyeicosanoate. The relationship of these glycolipids to different morphological forms of M. tuberculosis and to virulence is discussed.     

Lipid composition of the electron transport membrane of Haemophilus parainfluenzae

The principal lipids associated with the electron transport membrane of Haemophilus parainfluenzae are phosphatidylethanolamine (78%), phosphatidylmonomethylethanolamine (0.4%), phosphatidylglycerol (18%), phosphatidylcholine (0.4%), phosphatidylserine (0.4%), phosphatidic acid (0.2%), and cardiolipin (3.0%). Phospholipids account for 98.4% of the extractible fatty acids. There are no glycolipids, plasmalogens, alkyl ethers, or lipo amino acid esters in the membrane lipids. Glycerol phosphate esters derived from the phospholipids by mild alkaline methanolysis were identified by their staining reactions, mobility on paper and ion-exchange column chromatography, and by the molar glycerol to phosphate ratios. Eleven diacyl phospholipids can be separated by two-dimensional thin-layer chromatography. Each lipid served as a substrate for phospholipase D, and had a fatty acid to phosphate ratio of 2:1. Each separated diacyl phospholipid was deacylated and the glycerol phosphate ester was identified by paper chromatography in four solvent systems. Of the 11 separated phospholipids, 3 were phosphatidylethanolamines, 2 were phosphatidylserines, and 2 were phosphatidylglycerols. Phosphatidylcholine, cardiolipin, and phosphatidic acid were found at a single location. Phosphatidylmonomethylethanolamine was found with the major phosphatidylethanolamine. Three distinct classes of phospholipids are separable according to their relative fatty acid compositions. (i) The trace lipids consist of two phosphatidylethanolamines, two phosphatidylserines, phosphatidylcholine, phosphatidic acid, and a phosphatidylglycerol. Each lipid represents less than 0.3% of the total lipid phosphate. These lipids are characterized by high proportions of the short (C(10) to C(14)) and long (C(19) to C(22)) fatty acids with practically no palmitoleic acid. (ii) The major phospholipids (93% of the lipid phosphate) are phosphatidylethanolamine, phosphatidylmonomethylethanolamine, and phosphatidylglycerol. These lipids contain a low proportion of the short (C(19)) fatty acids. Palmitic and palmitoleic acids represent over 80% of the total fatty acids. (iii) The fatty acid composition of the cardiolipin is intermediate between the other two classes. Both palmitoleic and the longer fatty acids represent a significant proportion of the total fatty acid.     

A comparison of the fatty acid esters of estradiol and corticosterone synthesized by tissues of the rat

The biosynthesis of the fatty acid esters of the corticoid (corticosterone) and estrogen (estradiol) was compared in parallel incubations of corticosterone and estradiol with several tissues of the rat. The fatty acid composition of the esters of the two steroids was characterized in mammary and uterine tissue. In both of these tissues, the esters of estradiol were extremely heterogeneous. To the contrary, in the same tissues only one predominant ester of corticosterone, corticosterone-21-oleate, was formed. It comprised 70-80% of the total. The oleate ester of estradiol accounted for only 20% of the esters of this estrogen. In addition, fatty acid esters of an A-ring reduced metabolite of corticosterone, 5 beta-dihydrocorticosterone, was also identified. Its fatty acid composition is identical to that of corticosterone. In other experiments the fatty acid esters of both steroids were isolated from several tissues and quantified. When the amount of steroidal ester formed was compared, there was over a 100-fold difference among the various tissues in the ratio of estradiol to corticosterone ester synthesized. Thus, the rate of synthesis of the fatty acid esters of each class of steroid varies dramatically from tissue to tissue, and their fatty acid composition differs markedly as well. If the same enzyme synthesized both the estrogen and corticoid esters, then it would be expected that the relative amount of both esters synthesized in various tissues should be constant and likewise that their composition should be the same. Since neither occurred, these results suggest that the enzyme which produces the C-17 fatty acid esters of the estrogens may be different from the one which synthesizes the C-21 esters of the corticoids. The existence of separate enzyme systems for the synthesis of the fatty acid esters of these steroid hormones opens the possibility of specific physiological controls of each of these unusual steroidal metabolites.