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PubMed1995

Diets rich in eicosapentaenoic acid and gamma-linolenic acid affect phospholipid fatty acid composition and production of prostaglandins E1, E2 and E3 in turbot (Scophthalmus maximus), a species deficient in delta 5 fatty acid desaturase.

Duplicate groups of juvenile turbot, (Scophthalmus maximus), were fed diets containing either Marinol K (MO), a marine fish oil rich in eicosapentaenoic acid (EPA; 20:5, n-3) or borage oil (BO), rich in gamma-linolenic acid (GLA; 18:3, n-6), for a period of 12 weeks. Individual phospholipid fatty acid compositions from hearts of fish fed BO had significantly more 18:2, n-6, GLA, 20:2, n-6, dihomo-gamma-linolenic acid (DHGLA; 20:3, n-6) and total n-6 polyunsaturated fatty acids (PUFA), but significantly less arachidonic acid (AA; 20:4, n-6), compared to fish fed MO. In both phosphatidylcholine (PC) and phosphatidylethanolamine (PE) from heart, the DHGLA was increased by over 50-fold in fish fed BO while AA was reduced by over two-thirds, compared to fish fed MO. In brain, EPA was the major C20 PUFA, i.e. potential eicosanoid precursor in all phospholipids from fish fed MO, with the EPA level being twice that of AA in brain phosphatidylinositol (PI). DHGLA was the major C20 PUFA in all phospholipid classes from fish fed BO. In kidney and gill, EPA was the predominant C20 PUFA in all phospholipid classes, except PI, in fish fed MO. In kidney of fish fed BO, DHGLA was the major C20 PUFA in all phospholipid classes, except PE. In gill of fish fed BO, DHGLA was the major C20 PUFA in all phospholipid classes, including PI, where DHGLA was over 2.5-fold greater than AA. In homogenates of heart, kidney and gill from BO-fed fish the prostaglandin E1 (PGE1) concentration was significantly increased compared to MO-fed fish. In heart and kidney homogenates from fish fed MO the PGE3 concentration was significantly increased compared to fish fed BO. The ratio of PGE2/PGE1 was significantly reduced in brain, heart, kidney and gill homogenates from fish fed BO compared to those fed MO.

8,11,14-Eicosatrienoic Acid↗
PubMed2000

Polymorphism of linoleic acid (cis-9, cis-12-octadecadienoic acid) and alpha-linolenic acid (cis-9, cis-12, cis-15-octadecatrienoic acid).

Crystallization and polymorphic properties of linoleic acid (cis-9, cis-12-Octadecadienoic acid) (LA) and alpha-linolenic acid (cis-9, cis-12, cis-15-Octadecatrienoic acid) (alpha-LNA) have been studied by optical microscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The DSC analyses presented three polymorphs in LA, and two polymorphs in alpha-LNA. The XRD patterns of the higher- and lower-temperature forms in LA and alpha-LNA showed orthorhombic O'(//)+O-like and O'(//) subcell, which were similar to those of alpha- and gamma-forms of mono-unsaturated fatty acids, respectively. From the solvent crystallization of LA and alpha-LNA in acetonitrile, single crystals of the higher temperature polymorphs have been obtained. The crystal habits of truncated rhombic shape were also similar to those of alpha-forms of the mono-unsaturated fatty acids. The enthalpy and entropy values of fusion and dissolution of the alpha-forms of LA, alpha-LNA and oleic acid showed that the two values decreased with increasing number of the cis-double bond.

Calorimetry, Differential Scanning↗
PubMed1983

The organotypic tissue culture model of corticostriatal system used for examining amino acid neurotoxicity and its antagonism: studies on kainic acid, quinolinic acid and (-) 2-amino-7-phosphonoheptanoic acid.

Organotypic cultures of caudate nucleus and frontal cerebral cortex, either alone or in combination with each other, have been used to evaluate and compare the neurotoxic effects of two dicarboxylic amino acids, kainic acid (KA) and the tryptophan metabolite quinolinic acid (QUIN). Both of these agents can induce specific post-synaptic degeneration in cultures in which a complement of well-developed mature synapses exists. The neurotoxic effects of QUIN can be blocked by the synthetic anti-convulsant agent (-)2-amino-7-phosphonoheptanoic acid [( -]APH), but neurotoxicity of KA cannot. These studies support the candicacy of QUIN as an endogenous neurotoxin with properties similar to KA. Furthermore, the studies demonstrate the usefulness of the organotypic nerve tissue culture model as a research tool for examining certain neurodegenerative phenomena and for identifying neurotoxic amino acids as well as compounds which may antagonize amino acid neurotoxicity.

2-Amino-5-phosphonovalerate↗
PubMed2002

Simultaneous analysis of dehydroacetic acid, benzoic acid, sorbic acid and salicylic acid in cosmetic products by solid-phase extraction and high-performance liquid chromatography.

A high-performance liquid chromatographic (HPLC) method for simultaneous determination of dehydroacetic acid (DHA), benzoic acid (BA), sorbic acid (SOA) and salicylic acid (SA) was developed for application to cosmetic products. Isocratic reversed-phase HPLC was employed for quantitative analysis using tetra-n-butylammonium (TBA) hydroxide as an ion-pair reagent. Cosmetic samples were purified by solid-phase extraction using Bond-Elut SI cartridges. Four acidic preservatives were eluted with methanol from cartridges. The HPLC assay was carried out using TSK gel ODS-80TM column (5 microm, 150 x 4.6 mm I.D.). The mobile phase consisted of a mixture of water and methanol (65:35, v/v) containing 2.5 mM TBA hydroxide adjusted with phosphoric acid to pH 7.0. The calibration curves of these preservatives showed good linearity with UV detection (235 nm). The correlation coefficients were better than 0.999 in all cases. The lower limits of detection (defined as a signal-to-noise ratio of about 3) were approximately 2.5 ng for DHA, 4.0 ng for BA, 2.0 ng for SOA and 5.5 ng for SA. The procedure described here is simple, selective and is suitable for quality control of finished cosmetic products.

Benzoic Acid↗
PubMed1983

Endogenous levels of abscisic Acid and decanoic Acid in dutch iris bulbs and the influence of abscisic Acid and decanoic Acid on iris meristems cultured in vitro.

Abscisic acid (ABA) and decanoic acid inhibited shoot elongation and floral development of Dutch iris (Iris hollandica Hoog. cv Ideal) meristems cultured in vitro. No synergism with respect to inhibition of leaf growth between ABA and decanoic acid was observed. With monthly harvest dates, from July 10, 1981 to October 10, 1981, there was a progressive decrease in endogenous level of free ABA in ;Ideal' iris bulbs. Bulbs subjected to a full set of the usual preplanting storage conditions flowered, on average, 46 days after planting versus 194 days after planting for bulbs planted directly after harvest. ABA levels at harvest were 4- to 5-fold those after the preplanting storage treatment. In general, ABA levels did not correlate well with the length of time from planting until flowering of iris bulbs. Endogenous decanoic acid levels did not follow any pattern with respect to harvest date or postharvest treatment. After the postharvest high temperature treatment, there was about a 3-fold increase in nonscale decanoic acid concentration. Decanoic acid levels, in nonscale tissue, remained high after each of the other postharvest treatments. It is concluded that there is no good evidence to support the contention that either ABA or decanoic acid is directly involved in iris bulb dormancy.

Journal Article↗
PubMed1998

Effect of gammalinolenic acid, dihomogammalinolenic acid, ascorbyl-6-gammalinolenic acid, and ascorbyl-6-dihomo gammalinolenic acid on histamine- and methacholine-induced contraction of the isolated guinea pig tracheal chain.

The relaxant effects of gammalinolenic acid (GLA) and dihomo gammalinolenic acid (DGLA) were compared to the relaxant effect of arachidonic acid (AA). The effect of the combination of ascorbate to form the novel drugs ascorbyl-6-gammalinolenic acid (ascorbyl-6-GLA) and ascorbyl-6-dihomo gammalinolenic acid (ascorbyl-6-DGLA) were investigated and the role of the epithelial cells was determined. Salbutamol was used as control. The isolated tracheas of six to eight guinea pigs were used in each experiment and suspended in organ baths filled with Krebs-Henseleit solution and aerated with 95% O2 and 5% CO2. The relaxant effects produced for histamine-contracted preparations were as follows: AA=71.2+/-0.2%, GLA=55.2+/-4.2%, DGLA=69.8+/-3.9%, ascorbyl-6-GLA =26.2+/-5.1% and ascorbyl-6-DGLA=54.5+/-2.4%. For methacholine-contracted preparations: AA=46.6+/-3.2%, GLA=55.0+/-9.5%, DGLA=61.8+/-2.7%, ascorbyl-6-GLA=40.0+/-8.0% and ascorbyl-6-DGLA=88.0+/-15.3%. Ascorbyl-6-GLA and ascorbyl-6-DGLA had mainly a decreased relaxant effect compared to GLA and DGLA, except ascorbyl-6-DGLA after methacholine-induced contraction, which showed a significant increased relaxant effect. The removal of the epithelium showed decreased relaxant effects for the drugs except AA, which showed increased values after methacholine contraction. Histamine-contracted preparations showed varied results. Ascorbyl-6-GLA showed an increased relaxant effect, DGLA was unaffected with no additional effect, and AA, GLA and ascorbyl-6-DGLA showed decreased relaxant effects. In conclusion, it is clear that the contractant and the availability of epithelial cells could ultimately determine the results, though the mechanism remains very complex. The benefit of added ascorbate is still unclear and warrants more investigation.

8,11,14-Eicosatrienoic Acid↗
PubMed2003

Effect of altered dietary n-3 fatty acid intake upon plasma lipid fatty acid composition, conversion of [13C]alpha-linolenic acid to longer-chain fatty acids and partitioning towards beta-oxidation in older men.

The effect of increased dietary intakes of alpha-linolenic acid (ALNA) or eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for 2 months upon plasma lipid composition and capacity for conversion of ALNA to longer-chain metabolites was investigated in healthy men (52 (SD 12) years). After a 4-week baseline period when the subjects substituted a control spread, a test meal containing [U-(13)C]ALNA (700 mg) was consumed to measure conversion to EPA, docosapentaenoic acid (DPA) and DHA over 48 h. Subjects were then randomised to one of three groups for 8 weeks before repeating the tracer study: (1) continued on same intake (control, n 5); (2) increased ALNA intake (10 g/d, n 4); (3) increased EPA+DHA intake (1.5 g/d, n 5). At baseline, apparent fractional conversion of labelled ALNA was: EPA 2.80, DPA 1.20 and DHA 0.04 %. After 8 weeks on the control diet, plasma lipid composition and [(13)C]ALNA conversion remained unchanged compared with baseline. The high-ALNA diet resulted in raised plasma triacylglycerol-EPA and -DPA concentrations and phosphatidylcholine-EPA concentration, whilst [(13)C]ALNA conversion was similar to baseline. The high-(EPA+DHA) diet raised plasma phosphatidylcholine-EPA and -DHA concentrations, decreased [(13)C]ALNA conversion to EPA (2-fold) and DPA (4-fold), whilst [(13)C]ALNA conversion to DHA was unchanged. The dietary interventions did not alter partitioning of ALNA towards beta-oxidation. The present results indicate ALNA conversion was down-regulated by increased product (EPA+DHA) availability, but was not up-regulated by increased substrate (ALNA) consumption. This suggests regulation of ALNA conversion may limit the influence of variations in dietary n-3 fatty acid intake on plasma lipid compositions.

Carbon Dioxide↗
PubMed2004

Synthesis and characterization of poly(dimer acid-brassylic acid) copolymer and poly(dimer acid-pentadecandioic acid) copolymer.

Poly(dimer acid-brassylic acid) [P(DA-BA)] copolymers and poly(dimer acid-pentadecandioic acid) [P(DA-PA)] copolymers were prepared by melt polycondensation of the corresponding mixed anhydride prepolymers. The copolymers were characterized by Fourier transform infrared (FTIR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), wide angle x-ray powder-diffraction, and thermal gravimetric analysis (TGA). In vitro studies show that all the copolymers are degradable in phosphate buffer at 37 degrees C, and leaving an oily dimer acid residue after hydrolysis for the copolymer with high content of dimer acid. The release profiles of hydrophilic model drug, ciprofloxcin hydrochloride, from the copolymers, follow first-order release kinetics. All the preliminary results suggested that the copolymer might be potentially used as drug delivery devices.

Alkanes↗
PubMed1977

Isotachophoretic analysis of mandelic acid, phenylglyoxylic acid, hippuric acid and methylhippuric acid in urine after occupational exposure to styrene, toluene and/or xylene.

A simple, rapid and sensitive analytical method has been developed for the determination of phenylglyoxylic acid, mandelic acid, hippuric acid and methylhippuric acid; 0-, m- and p-methylhippuric acids are partly separated. These compounds are found as metabolites after occupational exposure to styrene, toluene and xylene. The method has been applied successfully to samples extracted from human urine by diethyl ether. The method can be used to accurately and simultaneously determine as little as 0.5 nmole of all of these acids in less than 20 min.

Chromatography, Gas↗
PubMed2005

[Application of slightly acidic hypochlorous acid water to the dental field--setting expansion and compressive strength of dental gypsum mixed with slightly acidic hypochlorous acid water].

PURPOSE: This study investigated both the setting expansion and compressive strength of dental gypsum mixed with slightly acidic hypochlorous acid water for the prevention of hospital infection. METHODS: Slightly acidic hypochlorous acid water (PURESTER Mp-240B, Morinaga Milk Industry) was used to mix each of three types of gypsum (model plaster, dental stone and high strength dental stone), and both the setting expansion and compressive strength of these gypsum products were analyzed in comparison with those mixed with tap water. RESULTS: 1. With regard to the setting expansion, a significant difference was not observed between gypsum products mixed with the two types of water, except for both the model plaster and dental stone 30 minutes after the start of mixing. 2. Regarding the compressive strength, a significant difference was not observed between gypsum products mixed with the two types of water, except for the model plaster 90 minutes after the start of mixing. CONCLUSIONS: From the results of the study, it was revealed that both the setting expansion and compressive strength of gypsum products using the slightly acidic hypochlorous acid water showed almost the same characteristics as those using tap water.

Calcium Sulfate↗
PubMed1982

The intracellular acid-extractable (acid-soluble) amino acid pool in mammalian cells: 4 An hypothesis to explain the effects of preloading on the exchange of amino acids across the cell membrane.

Intracellular acid-extractable pools preloaded with amino acids before the cells were placed in lower concentrations of labelling amino acid showed a massive infiltration of the label at resuspension. In some the overshoot was rapid, in others it was slower developing, but in all cases the final level returned to the control value. Some amino acids can produce an overshoot in preloaded pools of others, whereas in certain combinations, e.g. alanine preloaded cells challenged with leucine, no discernible change in uptake kinetics was seen. Discharge of the preloaded pool is a necessary prerequisite for overshoot since cells placed in challenges of equal concentration to the preloading conditions do not exhibit this phenomenon. There is no energy requirement for the rapid phase of overshoot to occur since it follows similar kinetics at 2 degrees and 37 degrees C. The results are discussed in terms of exchange reactions occurring within the acid-extractable pool which is composed of amino acids in a complexed form, and a hypothesis is offered to explain the phenomenon. This hypothesis is consistent with the cyclical perfusion model of Wheatley and Inglis (1980), and does not contravene Fick's law ans the second law of thermodynamics.

Alanine↗
PubMedDate not supplied

Absorption of amino acids in different parts of the small intestine in growing pigs. II. Effect of addition of certain amino acids on absorption of different amino acids from acid hydrolysed casein.

The study was carried out on pigs weighing 50 to 60 kg with temporarily isolated loops of the upper and the distal halves of the small intestine. Isolated segments 90 to 180 cm long were perfused at a rate of 720 ml/h with solutions of acid casein hydrolysate to which 100 to 300 per cent of the original contents of some amino acids was added. The changes of amino acid composition of the solution used for perfusion influenced to a large extent of the absorption of different amino acids. Leucine, methionine and arginine, the amino acids with the greatest affinity to the transport mechanism, were most active in inhibiting the absorption of the other amino acids from the small intestine.

Amino Acids↗
PubMed1995

Effects of hyodeoxycholic acid and alpha-hyocholic acid, two 6 alpha-hydroxylated bile acids, on cholesterol and bile acid metabolism in the hamster.

The effects of hyodeoxycholic (HDCA) and alpha-hyocholic acids (alpha-HCA), on cholesterol, bile acid and lipoprotein metabolism, were studied in hamsters. The animals were fed a low cholesterol control diet supplemented with 0.1% HDCA or alpha-HCA for 3 weeks. In both treated groups, the LDL-cholesterol concentration was significantly lowered and was associated with a global hypocholesterolemic effect. Moreover, hepatic cholesterol ester storage was reduced and HMGCoA reductase activity was respectively enhanced 13.5-times and 7.7-times in HDCA and alpha-HCA groups compared to controls. In contrast, cholesterol 7 alpha-hydroxylase activity and LDL-receptor activity and mass were not modified. In bile, the cholesterol saturation index was increased 5-fold (HDCA group) and 2-fold (alpha-HCA group) as a consequence of an enlarged proportion of biliary cholesterol. The two 6-hydroxylated bile acids induced an enhanced fecal excretion of neutral sterols (HDCA group: 11.6-times, alpha-HCA group: 3.2-times versus controls) which was consistent with a 59% decrease in intestinal cholesterol absorption in the HDCA group. The major effects due to bile acid treatments were a decrease in LDL-cholesterol concentration, a strong stimulation of hepatic cholesterol biosynthesis and an excessive loss of cholesterol in feces. These perturbations might be the result of the enrichment of bile with hydrophilic bile acids, leading to a limited return of endogenous cholesterol from the intestine to the liver.

Animals↗