The chemical constitution of carcinolipin

1. The neutral portion of the molecule of carcinolipin was found to be cholesterol by comparison of mixed melting points with cholesterol, its dibromide and its acetate. 2. The fatty acid present in carcinolipin was subjected to oxidative degradation by chromic acid and permanganate. Butan-2-one was the main neutral degradation product resulting from both these procedures. A mixture of dibasic acids was obtained after the oxidation with chromic acid. Permanganate oxidation yielded a complete homologous series of branched-chain C(5)-C(17) fatty acids. 3. The mass spectrum of the acid was characteristic for a saturated C(17) acid. The alcohol prepared by lithium aluminium hydride reduction of the original acid showed a mass spectrum typical for an anteiso compound. 4. Comparison of mixed melting points, gas-liquid-chromatographic behaviour and mass spectra of the fatty acid isolated from carcinolipin with an authentic sample of 14-methylhexadecanoic acid demonstrated the identity of these compounds. Cholesterol esters synthesized from authentic cholesterol and the fatty acid isolated from carcinolipin or synthetic 14-methylhexadecanoic acid showed an identical stimulating effect on the incorporation of labelled algal-protein hydrolysate into rat liver transfer RNA in vitro. 5. Mass spectra, results of oxidative degradations and comparisons with an authentic sample, as well as biological activity of the synthetic cholesterol 14-methylhexadecanoate, provided good evidence that carcinolipin is cholesterol (+)-14-methylhexadecanoate.     

The reduction of aliphatic and aromatic N-oxides to the corresponding amines with titanium(III) chloride

Amine N-oxides have been observed to be reduced by titanium(III) chloride. To study this reaction, 24 model amine N-oxides were reacted with titanium(III) chloride. The products of these reactions were shown by melting (boiling) points, mixed melting points, derivatives, refractive indices, infrared, and NMR comparisons with authentic compounds to be the corresponding amines. The reductions were found to require 2 moles of titanium(III) per mole of amine N-oxide.     

Emergence timing and fitness consequences of variation in seed oil composition in Arabidopsis thaliana

Early seedling emergence can increase plant fitness under competition. Seed oil composition (the types and relative amounts of fatty acids in the oils) may play an important role in determining emergence timing and early growth rate in oilseeds. Saturated fatty acids provide more energy per carbon atom than unsaturated fatty acids but have substantially higher melting points (when chain length is held constant). This characteristic forms the basis of an adaptive hypothesis that lower melting point seeds (lower proportion of saturated fatty acids) should be favored under colder germination temperatures due to earlier germination and faster growth before photosynthesis, while at warmer germination temperatures, seeds with a higher amount of energy (higher proportion of saturated fatty acids) should be favored. To assess the effects of seed oil melting point on timing of seedling emergence and fitness, high‐ and low‐melting point lines from a recombinant inbred cross of Arabidopsis thaliana were competed in a fully factorial experiment at warm and cold temperatures with two different density treatments. Emergence timing between these lines was not significantly different at either temperature, which aligned with warm temperature predictions, but not cold temperature predictions. Under all conditions, plants competing against high‐melting point lines had lower fitness relative to those against low‐melting point lines, which matched expectations for undifferentiated emergence times.     

Crystal structures and thermotropic properties of alkyl alpha-D-glucopyranosides and their hydrates

Thermotropic properties and crystal structures of alkyl alpha-D-glucopyranosides and their hydrates were estimated by X-ray, DSC and thermogravimetric measurements (TGA). Monohydrates rapidly lose their crystal water several degrees below the melting point of the anhydrous glucopyranosides. The melting points of the monohydrates measured in DSC pressure cells (chain length longer than seven) are lower, and the clearing points higher than those of the anhydrous glucosides. Layer distances of smectic and crystalline phases of anhydrous compounds were established. Melting points, densities and layer distances of the crystalline anhydrous glucopyranosides display strong even-odd effects. The strong decrease of these effects in the case of the monohydrates can be elucidated by the results of X-ray crystal structure analysis.     

Fatty acids,Part 35 the preparation and properties of the complete series of methyl epoxyoctadecanoates

The complete series of methyl epoxyoctadecanoates (31 isomers) has been made by epoxidation of the octadecenoates. The melting points of the acids are reported along with the chromatographic (TLC and GLC) and spectroscopic (NMR and MS) behaviour of the methyl esters.     

Separation and Identification of Fatty Acids

For the characterization of fatty acids, 2, 4-dinitrophenylhydrazones of p-bromophenacyl esters of even-numbered saturated fatty acids from C₂ to C₂₀ and several unsaturated fatty acids from monoethenoid to triethenoid were prepared. The derivatives of linoleic and linolenic acids as well as those of the other unsaturated and saturated acids, were successfully obtained in crystalline forms which showed sharp and high melting points, 72° and 69°, respectively. It was found that the derivatives of unsaturated acids were valuable for characterizing the parent acids, while those of saturated acids were unsuitable for this purpose owing to the similarity of their melting points.     

Estimation of melting points of large set of persistent organic pollutants utilizing QSPR approach

The presence of polyhalogenated persistent organic pollutants (POPs), such as Cl/Br-substituted benzenes, biphenyls, diphenyl ethers, and naphthalenes has been identified in all environmental compartments. The exposure to these compounds can pose potential risk not only for ecological systems, but also for human health. Therefore, efficient tools for comprehensive environmental risk assessment for POPs are required. Among the factors vital for environmental transport and fate processes is melting point of a compound. In this study, we estimated the melting points of a large group (1419 compounds) of chloro- and bromo- derivatives of dibenzo-p-dioxins, dibenzofurans, biphenyls, naphthalenes, diphenylethers, and benzenes by utilizing quantitative structure—property relationship (QSPR) techniques. The compounds were classified by applying structure-based clustering methods followed by GA-PLS modeling. In addition, random forest method has been applied to develop more general models. Factors responsible for melting point behavior and predictive ability of each method were discussed.     

Ahmad-Strong synthesis of 8-, 9-, and 10-pentadecynoic acids

Three pentadecynoic acids, with the triple bond in the 8-, 9-, and 10-positions, have been synthesized on a gram scale in over-all yield of 65% by refinements of the five-step Ahmad-Strong method; isolation of intermediates was shown to be unnecessary prior to purification of the acetylenic nitriles by column chromatography on silicic acid. The melting points of the pentadecynoic acids alternate regularly and widely with position of unsaturation, in marked contrast to behavior of the homologous octadecynoic acids described by Huber.     

Thermal denaturation of DNA in situ as studied by acridine orange staining and automated cytofluorometry

Thermal denaturation of nuclear DNA is studied in situ in individual cells or isolated cell nuclei by employing the property of the fluorochrome acridine orange (AO) to differentially stain native and denatured DNA and by using an automated flow-through cytofluorimeter for measurement of cell fluorescence. RNAse-treated cells, or cell nuclei, are heated, stained and measured while in suspension and AO-DNA interaction is studied under equilibrium conditions. Measurements are made rapidly (200 cells/sec); subpopulations of cells from a measured sample can be chosen on the basis of differences in their staining or light-scattering properties and analysed separately. DNA denaturation in situ is rapid; it approaches maximum during the first 5 min of cell heating. Divalent cations stabilize DNA against denaturation. At low pH the transition occurs at lower temperature and the width of the transition curves (‘melting profiles’) is increased. Decrease in ionic strength lowers the DNA melting temperature. This effect is much more pronounced in cells pretreated with acids under conditions known to remove histones. Histones thus appear to stabilize DNA in situ by providing counterions. At least four separate phases can be distinguished in melting profiles of DNA in situ; they are believed to indicate different melting points of DNA in complexes with particular histones. A decrease in cell (nuclear) ability to scatter light coincides with DNA melting in situ, possibly representing altered refractive and/or reflective properties of cell nuclei. Formaldehyde, commonly used to prevent DNA renaturation, is not used in the present method. The heat-induced alterations in nuclear chromatin are adequately stabilized after cell cooling in the absence of this agent. Cells heated at 60–85 °C exhibit increased total fluorescence after AO-staining, which is believed to be due to unmasking of new sites on DNA. This increase is neither correlated with DNA melting, nor with the presence of histones. Possibly, it reflects destruction of DNA superstructure maintained at lower temperatures by DNA associations with other than histone macromolecules (nuclear membrane).     

The role of polyunsaturated fatty acids in fish

The physical properties of polyunsaturated and saturated fatty acids are compared in relation to melting points and fluidity. The role of polyunsaturated fatty acids on membrane fluidity and membrane bound enzyme activity is discussed. The influence of the environment, particularly temperature, on poikilothermic animals is considered in relation to membrane fatty acid composition and metabolism. The metabolic role of polyunsaturated fatty acids of the (n-3) series and their interaction with arachidonate metabolism is discussed.     

Studies on the Flavors of Roast Barley (Mugi-Cha)

Five weakly acidic carbonyl compounds and two neutral carbonyl compounds were newly isolated as their 2,4-dinitrophenylhydrazones besides the previously reported compounds by using column and thin-layer chromatographies.

These compounds were characterized and identified by their IR, UV and MS spectra and the mixed melting points test.

The newly isolated and identified compounds were as follows; weakly acidic carbonyl compounds: 2-pyrrolealdehyde, vanillin, p-hydroxybenzaldehyde, syringaldehyde, proto-catechuic aldehyde, neutral carbonyl compounds: glyoxal, 5-hydroxymethylfurfural.

These compounds, particularly vanillin, protocatechuic aldehyde, 2-pyrrolealdehyde and 5-hydroxymethylfurfural, appeared to be concerned with the flavor of roast barley (Mugi-Cha).     

Synthesis and properties of novel 2'-O-alkoxymethyl-modified nucleic acids

Novel 2'-O-modified oligoribonucleotides with alkoxymethyl skeletons were synthesized, and their ability to hybridize complementary nucleic acids and their nuclease resistance were analyzed. The hybridization ability was improved by introducing electron-withdrawing groups and the increases in melting temperature (T(m) value) was particularly high for chlorine-substituted compounds. Nuclease resistance of these 2'-O-alkoxymethylated oligomers was lower than expected, but cyano substitution resulted in a higher nuclease resistance than 2'-O-methylation.     

Design of bioavailable derivatives of 12-(3-adamantan-1-yl-ureido)dodecanoic acid, a potent inhibitor of the soluble epoxide hydrolase

The soluble epoxide hydrolase (sEH) plays an important role in the metabolism of endogenous chemical mediators involved in blood pressure regulation and vascular inflammation. 12-(3-Adamantan-1-yl-ureido)-dodecanoic acid (AUDA, 1) is a very active inhibitor of sEH both in vitro and in vivo. However, its relatively high melting point and limited solubility in either water or oil-based solvents leads to difficulties in formulating the compound and often results in poor in vivo availability. We investigated the effect of derivatization of the acid functional group of inhibitor 1 on the inhibition potencies, physical properties, and pharmacokinetic properties. For human sEH, similar inhibition potency was obtained when the acid of compound 1 was modified to esters (2-15). The resulting compounds exhibited improved physical properties (23-66 degrees C lower melting point and 5-fold better solubility in oil). Pharmacokinetic studies showed that the esters possess improved oral bioavailability in mice. On the other hand, amide derivatives of AUDA 1 did not show significant improvement in inhibition potencies or physical properties (higher melting points and lower solubility). The esterification of 1 results in compounds that are easier to formulate in animal food and in triglycerides for gavage and other routes of administration, making it easier to study the biological effects of sEH inhibition in vivo.     

Nutritional evaluation of structured lipid containing omega 6 fatty acid synthesized from coconut oil in rats

Coconut oil is rich in medium chain fatty acids, but deficient in polyunsaturated fatty acids (PUFA). Structured lipids (SL) enriched with omega 6 PUFA were synthesized from coconut oil triglycerides by employing enzymatic acidolysis with free fatty acids obtained from safflower oil. Rats were fed a diet containing coconut oil, coconut oil-safflower oil blend (1:0.7 w/w) or structured lipid at 10% levels for a period of 60 days. The SL lowered serum cholesterol levels by 10.3 and 10.5% respectively in comparison with those fed coconut oil and blended oil. Similarly the liver cholesterol levels were also decreased by 35.9 and 26.6% respectively in animals fed structured lipids when compared to those fed on coconut oil or the blended oil. Most of the decrease observed in serum cholesterol levels of animals fed structured lipids was found in LDL fraction. The triglyceride levels in serum showed a decrease by 17.5 and 17.4% while in the liver it was reduced by 45.8 and 23.5% in the structured lipids fed animals as compared to those fed coconut oil or blended oil respectively. Differential scanning calorimetric studies indicated that structured lipids had lower melting points and solid fat content when compared to coconut oil or blended oils. These studies indicated that enrichment of coconut oil triglycerides with omega 6 fatty acids lowers its solid fat content. The omega 6 PUFA enriched structured lipids also exhibited hypolipidemic activity.     

Activation of branched and other long-chain fatty acids by rat liver microsomes

Acyl coenzyme A synthetase (EC 6.2.1.3) of rat liver microsomes activates iso- and anteiso-branched long-chain fatty acids containing 12 to 20 carbon atoms. Fatty acid chain length appears to be the major determinant of the maximum rate of acyl CoA biosynthesis of branched, or saturated, or cis monounsaturated long-chain fatty acids. Based on activation studies conducted at 22-45 degrees C, it is concluded that the rate of activation is a function of long-chain fatty acid solubility. The shape of the in vitro activation curve with respect to fatty acid concentration appears to be determined by fatty acid melting point as well as by the presence and position of double bonds. Differently shaped activation curves were observed for cis or trans Delta(6) to Delta(12) central positional isomers of octadecenoic acid and for Delta(3), Delta(4), Delta(13) to Delta(15) terminal isomers of octadecenoic acid. The relationships between fatty acid structure, melting point, solubility, and shape of the activation curve observed during in vitro measurement of acyl CoA formation are discussed.     

Ethanol-induced changes in the membrane lipid composition of Clostridium thermocellum

When ethanol is added to the growth medium of Clostridium thermocellum ATCC 27405 and C9, a different membrane composition is observed after the period of growth arrest. Changes in fatty acid composition and some unsaturated, branched hydrocarbons have been monitored by GLC-MS. There is a marked increase in normal and anteiso-branched fatty acids at the expense of isobranched fatty acids and an increase in short and unsaturated fatty acids. Thus, an adaptive response to growth in the presence of ethanol induces a membrane containing fatty acids with lower melting points and produces a more ‘fluid’ membrane. The suggestion is made that these membrane changes may be maladaptive to the performance of C. thermocellum.     

Bovine serum albumin enhances nicotinic acetylcholine receptor function in mouse thalamic synaptosomes

Bovine serum albumin (BSA) enhances nicotinic agonist-induced (86)Rb+ efflux from synaptosomal fractions of the mouse thalamus, but how it does so is not understood. The experiments reported here indicated that BSA enhancement of nicotinic acetylcholine receptor function was rapid, reversible, depended on BSA concentration, and occurred at all points of the nicotinic agonist concentration-response curve. We hypothesized that BSA-extractable compounds, such as long-chain fatty acids, were responsible for inhibiting nicotinic responses in the absence of BSA. The hypothesis was tested by applying arachidonic, linolenic, or oleic acids in the absence of BSA after an initial prewash with BSA. All three fatty acids exhibited a rapid, concentration-dependent inhibition of nicotinic-agonist stimulated ion flux. Concentration-response curves produced after 30 s of pre-treatment with arachidonic acid were similar to those seen when BSA was completely absent. The effects of pre-treatment were reversed immediately by the introduction of BSA. Furthermore, no effects of fatty acids were observed when preparations were continuously exposed to BSA or when BSA was continuously absent. These results suggest that the removal of endogenous, inhibitory compounds is largely responsible for the rapid, potentiating action of BSA at nicotinic acetylcholine receptors expressed in the mouse thalamus.     

Biochemical characterization of blood orange,sweet orange,lemon, bergamot and bitter orange

This paper reports on the composition of aroma compounds and fatty acids and some physico-chemical parameters (juice percentage, acidity and total sugars) in five varieties of citrus: blood orange, sweet orange, lemon, bergamot and bitter orange. Volatile compounds and methyl esters have been analyzed by gas chromatography. Limonene is the most abundant compound of monoterpene hydrocarbons for all of the examined juices. Eighteen fatty acids have been identified in the studied citrus juices, their quantification points out that unsaturated acids predominate over the saturated ones. Mean concentration of fatty acids varies from 311.8 mg/l in blood orange juice to 678 mg/l in bitter orange juice.     

Quantitative trait loci mapping for fatty acid composition traits in perirenal and back fat using a Japanese wild boar x Large White intercross

Here, we analysed quantitative trait loci (QTL) for fatty acid composition, one of the factors affecting fat quality, in a Japanese wild boar x Large White cross. We found 25 significant effects for 17 traits at 13 positions at the 5% genome-wise level, of which 16 effects for 12 traits at 10 positions were significant at the 1% level. QTL for saturated fatty acids (SFA) in back fat were mapped to swine (Sus scrofa) chromosomes (SSC) 1p, 9 and 15. QTL for unsaturated fatty acids in back fat were mapped to SSC1p, 1q, 4, 5, 9, 15 and 17. Using a regression model that fits back fat thickness as a covariate, two of the QTL for linoleic acid content on SSC4 and SSC17 were not significant, but one QTL for total SFA composition was detected on SSC5 with correction for back fat thickness. Wild boar alleles at six of seven QTL tended to increase SFAs and to decrease unsaturated fatty acids. QTL for fatty acid composition in perirenal fat were mapped on SSC2, 3, 4, 5, 6, 14, 16 and X. QTL for melting point (in back fat samples) were mapped on SSC1, 2 and 15. Wild boar alleles in QTL on SSC1 and SSC15 were associated with elevated melting points whereas those on SSC2 were associated with lower melting point measurements.