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[Studies on chemical constituents of fat oil of Polygala tenuifolia].

OBJECTIVE: To study the chemical constituents of fat oil from root of Polygala tenuifolia Willd. METHOD: The components were separated and identified by gas chromatograpy-mass spectrometry and elucidated on the standard mass spectral data and the percentages were determined by gas chromatographic area normalization method. RESULT: Eighteen constituents were separated and sixteen of them were identified. CONCLUSION: The major components of the fat oil were established first time as oleic acid, linoleic acid, palmitic acid, eicosenoic acid and stearic acid, which make up 87.0%, 7.31%, 3.27%, 1.07%, 0.91% of fat oil respectively.

Fatty Acids↗

Evidence for the importance of iron in the alpha-oxidation of 3-methyl-substituted fatty acids in the intact cell.

Preincubation of isolated rat hepatocytes with desferrioxamine or o-phenanthroline, two iron-specific chelators, strongly suppressed the CO2-production from the alpha-oxidation of 3-methylmargaric acid, whereas the beta-oxidation of 2-methylpalmitic acid, palmitic acid, trihydroxycoprostanic acid and the conversion of formic acid to CO2 were not affected. When, after the initial preincubation with the chelators and prior to the addition of 3-methylmargaric acid, iron-saturated transferrin and Fe3+ were added, a partial restitution of the CO2-production rates was obtained. These facts provide further evidence for the importance of iron in the alpha-oxidation of 3-methyl-substituted fatty acids.

Animals↗

Proton transport at the monolayer-water interface.

It is shown that when monolayers of stearic acid, palmitic acid, DPPC, or DPPS are compressed above some critical area Ac a lateral conduction mechanism is initiated at the monolayer/water interface. The interfacial conductance increases on further increasing the molecular packing density in the monolayer. All compounds also show major changes in surface potential at Ac the potential becoming more positive in all cases. It is argued that this is a consequence of structural reorganisation at the headgroup/water interface causing a significant reduction in the local permittivity. The critical area, Ac, is approximately double the molecular areas estimated from the pressure-area isotherm, and experiments with stearic acid monolayers show that Ac decreases significantly when the chaotropic ion SCN-, which is known to disrupt the molecular structure of water, is added to the subphase. It is likely, therefore, that the structural changes occurring at Ac involve the formation of a hydrogen bonded network between monolayer headgroups and adjacent water molecules at the monolayer/water interface. It is suggested that the conduction mechanism initiated at Ac arises from proton hopping along this hydrogen-bond network.

1,2-Dipalmitoylphosphatidylcholine↗

Effects of increasing dietary palmitoleic acid compared with palmitic and oleic acids on plasma lipids of hypercholesterolemic men.

Palmitoleic acid is a minor monounsaturated fatty acid in the human diet and in blood plasma. Because macadamia oil is at least one potentially large source of palmitoleic acid, we tested its effect on plasma lipid levels against two other dietary fatty acids, oleic acid and palmitic acid. The dietary adjustments, through the use of supplements, provided comparisons of the three test fatty acids in which palmitoleic could be judged as behaving either like a saturated or a monounsaturated acid. Thirty-four hypercholesterolemic men ate the three test diets in random order in 3-week periods. Plasma total cholesterol and low density lipoprotein (LDL) cholesterol concentrations were similar with palmitic and palmitoleic acids and significantly higher than with oleic acid. High density lipoprotein (HDL) cholesterol was significantly lower with palmitoleic than with palmitic acid. The study confirms that, at least in hypercholesterolemic men, a modest increase in palmitic acid (+4% en) raises LDL cholesterol relative to oleic acid (+3% en), even when dietary cholesterol is low (< 165 mg/day). Palmitoleic acid (+4% en) behaves like a saturated and not a monounsaturated fatty acid in its effect on LDL cholesterol.

Cholesterol, LDL↗

LIPIDS OF DEBARYOMYCES HANSENII.

Merdinger, Emanuel (Roosevelt University, Chicago, Ill.), and Edward M. Devine, Jr. Lipids of Debaryomyces hansenii. J. Bacteriol. 89:1488-1493. 1965.-The separation of neutral lipids and phospholipids from the lipid extract of Debaryomyces hansenii NRRL Y-1448 was accomplished by using a single column packed with silicic acid. The neutral lipids comprised 67%, and the phospholipids 33%, of the total lipid extract. Qualitative and quantitative characterization of the lipids was effected by various analytical procedures. Gas chromatography of the fatty acid methyl esters showed 11 acids, of which 59.7% were unsaturated. The most abundant among the unsaturated acids was the monounsaturated C18 acid (50.1%). Among the saturated acids, palmitic acid (23.5%) prevailed. Ratios of fatty acid to glycerol, phosphorus to glycerol, and phosphorus to fatty acid were ascertained for combined cuts from the neutral lipids and the phospholipids. The presence of ergosterol, stigmasterol, and an unidentified sterol was established by gas chromatography. Also present were saturated hydrocarbons containing 16 to 39 carbon atoms, C22 being the most prevalent.

Chemical Phenomena↗

Platelet-activating factor regulates phospholipid metabolism in human neutrophils.

This study extended the earlier finding that platelet-activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) promotes arachidonic acid incorporation into neutrophil phosphatidylinositol (PI) and phosphatidylcholine (PC). In the present study the effect of PAF on fatty acid uptake by human neutrophils and the incorporation of extracellular linoleic acid and palmitic acid into phospholipids were investigated. Incubation of 10(-7) M PAF with neutrophils and radiolabeled arachidonic acid or linoleic acid or palmitic acid for 1-10 min resulted in an increased rate of loss of label from the incubation medium. PAF stimulated the incorporation of linoleic acid and palmitic acid most significantly into PI and PC. The magnitude of stimulation was greater in PI than in PC for the incorporation of linoleic acid, and vice versa for the incorporation of palmitic acid. The positional distribution of linoleic acid and palmitic acid in PI and PC and the mass of these phospholipids were not altered in PAF-stimulated neutrophils. An increased incorporation of all three fatty acids into both diacyl and alkylacyl species of PC was demonstrated after a two minute incubation of cells with PAF. While more radioactivity was recovered in the diacyl species, the magnitude of increase of radioactivity in the alkylacyl species was more pronounced than that in the diacyl species of PC. These results suggest that both increased fatty acid uptake and increased available lysophospholipids may be contributory to the increased phospholipid acylation induced by PAF.

Arachidonic Acids↗

Structural elucidation of fritillahupehin from bulbs of Fritillaria hupehensis Hsiao et K.C. Hsia.

A novel diterpenoid ester, fritillahupehin (1) and three known fatty acids, palmitic acid (2), lignoceric acid (3) and azelaric acid (4), have been isolated from the bulbs of Fritillaria hupehensis Hsiao et K.C. Hsia. The structure of fritillahupehin has been established to be ent-kauran-16beta-yl lignocerate by means of spectroscopic and chemical evidence. Compounds 2-4 were isolated from Fritillaria sp. for the first time.

Diterpenes↗

Analysis of the products from enzymatic scouring of cotton.

This article discusses the analysis of the hydrolysis products from one-step scouring of cotton using pectinase and two-step scouring of cotton using lipase then cellulase, protease then cellulase, or lipase/protease then cellulase, to improve water absorbency of cotton. UV spectrophotometric analysis indicated that the pectinase scouring process produced approximately 18-fold higher amounts of reducing sugars and galacturonic acid than any of the two-step scouring processes. The production rate of reducing sugars and galacturonic acid from most of the scouring processes showed a decrease with an increase in time. HPLC analysis revealed that the lipase/protease/cellulase scouring processes produced approximately 5-fold higher amounts of 17 amino acids than the pectinase scouring process. GC analysis for 18 fatty acids (C(8)-C(24)) revealed that three major fatty acids, palmitic acid, stearic acid, and behenic acid, were found on both the scoured and the unscoured fabrics. Scoured fabrics were tested for content of proteins, extractable components, waxes, and anionic components including pectins, and some differences among the fabric scoured with different enzyme combinations were found.

Cellulase↗

Structure of a novel diterpenoid ester, fritillahupehin from bulbs of Fritillaria hupehensis Hsiao and K.C. Hsia.

A new diterpenoid ester, fritillahupehin (1) together with three known fatty acids: palmitic acid (2), lignoceric acid (3) and azelaic acid (4) were isolated from the bulbs of Fritillaria hupehensis Hsiao and K.C. Hsia. The structure of fritillahupehin has been established to be ent-kauran-16beta-yl lignocerate by means of spectroscopic and chemical evidence. Compounds 2-4 were isolated from Fritillaria sp. for the first time.

Dicarboxylic Acids↗

Fatty acids present in the lipopolysaccharide of Rhizobium trifolii.

Approximately 70% of the fatty acids recovered after acid or alkaline hydrolysis of the lipopolysaccharide of Rhizobium trifolii were hydroxy fatty acids identified as hydroxymyristic and hydroxypalmitic acids. Palmitic acid was the only saturated fatty acid found in the lipopolysaccharide of R. trifolii. Octadecenoic and a small amount of hexadecenoic acids were also identified. The results of BF(3) methanolysis and hydroxylaminolysis suggest that hydroxypalmitic acid is N-acyl bound.

Chromatography, Gas↗

Molecular dynamics simulations of stratum corneum lipid models: fatty acids and cholesterol.

We report the results of an investigation on stratum corneum lipids, which present the main barrier of the skin. Molecular dynamics simulations, thermal analysis and FTIR measurements were applied. The primary objective of this work was to study the effect of cholesterol on skin structure and dynamics. Two molecular models were constructed, a free fatty acid bilayer (stearic acid, palmitic acid) and a fatty acid/cholesterol mixture at a 1:1 molar ratio. Our simulations were performed at constant pressure and temperature on a nanosecond time scale. The resulting model structures were characterized by calculating surface areas per headgroup, conformational properties, atom densities and order parameters of the fatty acids. Analysis of the simulations indicates that the free fatty acid fraction of stratum corneum lipids stays in a highly ordered crystalline state at skin temperatures. The phase behavior is strongly influenced when cholesterol is added. Cholesterol smoothes the rigid phases of the fatty acids: the order of the hydrocarbon tails (mainly of the last eight bonds) is reduced, the area per molecule becomes larger, the fraction of trans dihedrals is lower and the hydrophobic thickness is reduced. The simulation results are in good agreement with our experimental data from FTIR analysis and NIR-FT Raman spectroscopy.

Body Temperature↗

Composition of human serum sphingomyelins.

Serum sphingomyelins were analyzed by argentation chromatography of the corresponding ceramide diacetates. Six subfractions were obtained. Three of them contained 4-sphingenines in combination with saturated, trans-, or cis-monoenoic fatty acids; the remaining three contained sphingadienine, also in combination with saturated, trans-, or cis-monoenoic fatty acids. Palmitic acid was the principal fatty acid combined with 4-sphingenines, while nervonic acid was the principal fatty acid combined with sphingadienine. About 4% of the total fatty acids of sphingomyelin were trans-monoenoic. They were comprised of many positional isomers of straight-chain C(22-24) compounds. The cis-monoenoic acids made up 33% of the total acids and consisted of almost pure nervonic acid. The rest of the acids were saturated. The 4-sphingenines contained small amounts of iso-C(18) and anteiso-C(19) compounds in addition to the straight-chain C(16-18) bases.

Acetates↗

Impact of mitochondrial beta-oxidation in fatty acid-mediated inhibition of glioma cell proliferation.

Tetradecylthioacetic acid (TTA), which cannot be beta-oxidized, exerts growth-limiting properties in glioma cells. In order to investigate the importance of modulated lipid metabolism and alterations in mitochondrial properties in this cell death process, we incubated glioma cells both with TTA and the oxidizable fatty acid palmitic acid (PA), in the presence of L-carnitine and the carnitine palmitoyltransferase inhibitors etomoxir and aminocarnitine. L-carnitine partly abolished the PA-mediated growth reduction of glioma cells, whereas etomoxir and aminocarnitine enhanced the antiproliferative effect of PA. The production of acid-soluble products increased and the incorporation of PA into glycerolipids decreased after L-carnitine supplementation. L-carnitine was found to enhance the antiproliferative effect of TTA, but did not affect the incorporation of TTA into glycerolipids, or ceramide. PDMP, sphingosine 1-phosphate, desipramine, fumonisin B(1), and L-cycloserine were able not to rescue the glioma cells from PA and TTA-induced growth inhibition, suggesting that increased ceramide production is not important in the growth reduction. TTA-mediated growth inhibition was accompanied with an increased uptake of PA and increased incorporation of PA into triacylglycerol (TG). Our data suggest that mitochondrial functions are involved in fatty acid-mediated growth inhibition. Whether there is a causal relationship between TG accumulation and the apoptotic process remains to be determined.

Animals↗

Eicosanoids influence in vitro elongation of plasmatocytes from the tobacco hornworm, Manduca sexta.

Nodule formation is the predominant insect cellular defense reaction to bacterial challenges, responsible for clearing the largest proportion of infecting bacteria from hemolymph circulation. Hemocyte spreading behavior is a critical step in the nodulation process. It has been suggested that eicosanoids mediate several steps in the process. However, the influence of eicosanoids on hemocyte spreading has not been investigated in detail. To test the hypothesis that eicosanoids mediate hemocyte spreading behavior, I treated larvae of the tobacco hornworm, Manduca sexta, with eicosanoid biosynthesis inhibitors and later assessed plasmatocyte elongation on glass slides. Plasmatocytes from larvae treated with dexamethasone did not elongate to the extent of plasmatocytes from untreated control larvae. The dexamethasone effect on plasmatocyte elongation was expressed in a dose-dependent manner and was reversed by injecting dexamethasone-treated larvae with the eicosanoid-precursor fatty acid, arachidonic acid. Palmitic acid, which is not substrate for eicosanoid biosynthesis, did not reverse the influence of dexamethasone on plasmatocyte elongation. Finally, plasmatocytes from larvae treated with a range of eicosanoid biosynthesis inhibitors did not elongate to the extent of plasmatocytes from control larvae. Plasmatocyte width did not appear to be influenced in this study. These findings strongly support the idea that insect plasmatocyte elongation is influenced by eicosanoids.

Animals↗

[Chemical composition of Fordia cauliflora Hemsl].

OBJECTIVE: To study chemical constituents of the root of Fordia cauliflora. METHOD: Three compounds were obtained from the ethanolic extract of the roots of F. cauliflora by silica column chromatography, and identified by physico-chemical and spectroscopic analysis. RESULT: The compounds were identified as stearic acid, palmitic acid and beta-sitosterol. CONCLUSION: These compounds were obtained from this plant for the first time.

Fabaceae↗

[Studies on chemical constituents of Forsythia suspensa (Thunb) Vahl].

OBJECTIVE: To study the chemical constituents of Forsythia suspensa. METHOD: Basedon silicacolumn chromatography, of which six compounds were obtained from the alcohol extract of F. suspensa, three identified by physicochemical and spectroscopic analyses. RESULT: The three compounds were identified as stearic acid, palmitic acid and beta-sitosterol. CONCLUSION: The three compounds were separated from F. suspensa fruits for the first time.

Forsythia↗