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Chain Fatty Acids (chain + fatty_acid)
Kinds of Chain Fatty Acids Selected AbstractsEffect of Long Chain Fatty Acids on Organocatalytic Aqueous Direct Aldol ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009Nobuyuki Mase Abstract In an organocatalyzed, aqueous direct aldol reaction, the addition of a long chain fatty acid (1,mol%) such as stearic acid or erucic acid improved the aldol product yield and the enantioselectivity with low catalyst loading (1,mol%). The small particle size of the emulsion (less than 1,,m) was a key to the enhanced reactivity as shown by dynamic light scattering (DLS) analyses. [source] Metabolic Carbon Fluxes and Biosynthesis of Polyhydroxyalkanoates in Ralstonia eutropha on Short Chain Fatty AcidsBIOTECHNOLOGY PROGRESS, Issue 4 2004Jian Yu Short chain fatty acids such as acetic, propionic, and butyric acids can be synthesized into polyhydroxyalkanoates (PHAs) by Ralstonia eutropha. Metabolic carbon fluxes of the acids in living cells have significant effect on the yield, composition, and thermomechanical properties of PHA bioplastics. Based on the general knowledge of central metabolism pathways and the unusual metabolic pathways in R. eutropha,a metabolic network of 41 bioreactions is constructed to analyze the carbon fluxes on utilization of the short chain fatty acids. In fed-batch cultures with constant feeding of acid media, carbon metabolism and distribution in R. eutropha were measured involving CO2, PHA biopolymers, and residual cell mass. As the cells underwent unsteady state metabolism and PHA biosynthesis under nitrogen-limited conditions, accumulative carbon balance was applied for pseudo-steady-state analysis of the metabolic carbon fluxes. Cofactor NADP/NADPH balanced between PHA synthesis and the C3/C4 pathway provided an independent constraint for solution of the underdetermined metabolic network. A major portion of propionyl-CoA was directed to pyruvate via the 2-methylcitrate cycle and further decarboxylated to acetyl-CoA. Only a small amount of propionate carbon (<15% carbon) was directly condensed with acetyl-CoA for 3-hydroxyvalerate. The ratio of glyoxylate shunt to TCA cycle varies from 0 to 0.25, depending on the intracellular acetyl-CoA level and acetic acid in the medium. Malate is the node of the C3/C4 pathway and TCA cycle and its decarboxylation to dehydrogenation ranges from 0.33 to 1.28 in response to the demands on NADPH and oxaloacetate for short chain fatty acids utilization. [source] ChemInform Abstract: Effect of Long Chain Fatty Acids on Organocatalytic Aqueous Direct Aldol Reactions.CHEMINFORM, Issue 13 2010Nobuyuki Mase Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Acetate inhibits NFAT activation in T cells via importin ,1 interferenceEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 8 2007Kazuhiro Ishiguro Dr. Abstract Acetate is a principal short chain fatty acid produced by bacterial fermentation in the colon and a major end product of alcohol metabolism. In the present study, we assessed the effects of acetate on T cell activation and found that acetate inhibited NFAT activation but not NF-,B activation. Moreover, acetate impaired the nuclear translocation of NFAT but not that of NF-,B. Unlike cyclosporin A (CsA), acetate did not affect the dephosphorylation of NFAT and calcineurin activity. Acetate impaired the binding of NFAT to importin ,1, which is involved in NFAT nuclear translocation. NFAT is a critical transcription factor in cytokine and early response gene expression in activated T cells. Agents targeting NFAT such as CsA are used to suppress harmful immune responses in inflammatory diseases. Therefore, we also evaluated the efficacy of acetate in murine models of inflammatory diseases, and found that acetate administration (as well as administration of dexamethasone) attenuated trinitrobenzenesulfonic acid-induced colitis and dinitrofluorobenzene-induced dermatitis. These findings indicate for the first time that acetate inhibits NFAT activation by interfering with the interaction between NFAT and importin ,1 in T cells and that acetate can potentially act as an anti-inflammatory agent. [source] Expression of mitochondrial HMGCoA synthase and glutaminase in the colonic mucosa is modulated by bacterial speciesFEBS JOURNAL, Issue 1 2004Claire Cherbuy The expression of the colonic mitochondrial 3-hydroxy 3-methyl glutaryl CoA (mHMGCoA) synthase, a key control site of ketogenesis from butyrate, is lower in germ-free (GF) than in conventional (CV) rats. In contrast, the activity of glutaminase is higher. The objective of this study was to investigate whether the intestinal flora can affect gene expression through short chain fatty acid (SCFA) and butyrate production. GF rats were inoculated with a conventional flora (Ino-CV) or with a bacterial strain producing butyrate (Clostridium paraputrificum, Ino- Cp) or not (Bifidobacterium breve, Ino- Bb). In the Ino-CV rats, mHMGCoA synthase expression was restored to the CV values 2 days after the inoculation, i.e. concomitantly with SCFA production. In the Ino- Cp group, but not in the Ino- Bb group, mHMGCoA synthase and glutaminase were expressed at the level observed in the CV rats. These data suggest that the intestinal flora, through butyrate production, could control the expression of colonic mHMGCoA synthase and glutaminase. These modifications in gene expression by butyrate in vivo seem unrelated to a modification of histone acetylation. [source] Molecular basis of Refsum disease: Sequence variations in Phytanoyl-CoA Hydroxylase (PHYH) and the PTS2 receptor (PEX7),HUMAN MUTATION, Issue 3 2004Gerbert A. Jansen Abstract Refsum disease has long been known to be an inherited disorder of lipid metabolism characterized by the accumulation of phytanic acid (3,7,11,15-tetramethylhexadecanoic acid) caused by an ,-oxidation deficiency of this branched chain fatty acid in peroxisomes. The mechanism of phytanic acid ,-oxidation and the enzymes involved had long remained mysterious, but they have been resolved in recent years. This has led to the resolution of the molecular basis of Refsum disease. Interestingly, Refsum disease is genetically heterogeneous; two genes, PHYH (also named PAHX) and PEX7, have been identified to cause Refsum disease, as reviewed in this work. Hum Mutat 23:209-218, 2004. © 2004 Wiley-Liss, Inc. [source] Effect of Long Chain Fatty Acids on Organocatalytic Aqueous Direct Aldol ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009Nobuyuki Mase Abstract In an organocatalyzed, aqueous direct aldol reaction, the addition of a long chain fatty acid (1,mol%) such as stearic acid or erucic acid improved the aldol product yield and the enantioselectivity with low catalyst loading (1,mol%). The small particle size of the emulsion (less than 1,,m) was a key to the enhanced reactivity as shown by dynamic light scattering (DLS) analyses. [source] The emerging role of epigenetic modifications and chromatin remodeling in spinal muscular atrophyJOURNAL OF NEUROCHEMISTRY, Issue 6 2009Sebastian Lunke Abstract As the leading genetic cause for infantile death, Spinal Muscular Atrophy (SMA) has been extensively studied since its first description in the early 1890s. Though today much is known about the cause of the disease, a cure or effective treatment is not currently available. Recently the short chain fatty acid valproic acid, a drug used for decades in the management of epilepsy and migraine therapy, has been shown to elevate the levels of the essential survival motor neuron protein in cultured cells. In SMA mice, valproic acid diminished the severity of the disease phenotype. This effect was linked to the ability of the short chain fatty acid to suppress histone deacetylase activity and activate gene transcription. Since then, the study of different histone deacetylase inhibitors and their epigenetic modifying capabilities has been of high interest in an attempt to find potential candidates for effective treatment of SMA. In this review, we summarize the current knowledge about use of histone deacetylase inhibitors in SMA as well as their proposed effects on chromatin structure and discuss further implications for possible treatments of SMA arising from research examining epigenetic change. [source] Peroxisomal branched chain fatty acid ,-oxidation pathway is upregulated in prostate cancerTHE PROSTATE, Issue 4 2005Shan Zha Abstract Overexpression of ,-methylacyl-CoA racemase (AMACR), an enzyme involved in branched chain fatty acid ,-oxidation, in prostate cancer has been reported. Here, we report that an enzyme downstream from AMACR in the peroxisomal branched chain fatty acid ,-oxidation pathway,D -bifunctional protein (DBP),is also upregulated in prostate cancer at both mRNA and protein levels, accompanied by increased enzymatic activity. Furthermore, our data suggest that pristanoyl-CoA oxidase (ACOX3), which is expressed at extremely low level in other human organs studied including the liver, might contribute significantly to peroxisomal branched chain fatty acid ,-oxidation in human prostate tissue and some prostate cancer cell lines. In contrast to these results for peroxisomal enzymes, no significant expression changes of mitochondrial fatty acid ,-oxidation enzymes were observed in prostate cancer tissues through comprehensive quantitative RT-PCR screening. These data for the first time provide evidence for the selective over-activation of peroxisomal branched chain fatty acid ,-oxidation in prostate cancer, emphasizing a new metabolic change during prostate oncogenesis. © 2004 Wiley-Liss, Inc. [source] Postprandial lipemic response to alpha-linolenic acid rich oil, butter, and olive oilEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 9 2010Julia Svensson Abstract Postprandial lipemia varies with composition of dietary fat due to partitioning of fatty acids between ,-oxidation, incorporation into TAG, and tissue lipids. Effects of alpha-linolenic acid (ALA) are poorly characterized. Lipase-catalyzed transesterification was used to produce a novel ALA-oil (35% ALA) from rapeseed and linseed oil. We hypothesized a lower postprandial lipemic response with ALA-oil than with olive oil and butter due to higher ,-oxidation of ALA. A randomized crossover study with 26 healthy men compared the effects on plasma lipids 7,h after a breakfast containing 35,g ALA-rich oil, butter fat, or olive oil. The incremental area under curve for plasma TAG was lower with butter than with olive oil (34%, p<0.05) and ALA-oil (25%, ns). After ALA-oil percentage ALA increased, in TAG to a constant level of 7,mol% and in NEFA to 6% after 7,h. Since total NEFA increased with time the amount of exogenous ALA in NEFA also increased. Butter resulted in lower postprandial lipemia than the oils, the difference exceeding what is expected from the presence of short and medium chain fatty acids in butter. There was a considerable recirculation of ALA into the NEFA pool available for oxidation. Practical application: Enzymatic transesterification was used to produce a dietary oil rich in ALA. By randomizing the partitioning of ALA more evenly between the TAG molecules the risk of oxidation could be reduced. Analyses showed that the ALA-oil was stable during storage for at least 3 months. Enzymatic transesterification could be used as an advantageous method to design an ALA rich dietary oil with new properties regarding fatty acid composition, susceptibility to oxidation, and effects on blood lipids. [source] Myristyl and palmityl acylation of pI 5.1 carboxylesterase from porcine intestine and liverFEBS JOURNAL, Issue 4 2002Tissue, subcellular distribution Immunoblotting analyses revealed the presence of carboxylesterase in the porcine small intestine, liver, submaxillary and parotid glands, kidney cortex, lungs and cerebral cortex. In the intestinal mucosa, the pI 5.1 enzyme was detected in several subcellular fractions including the microvillar fraction. Both fatty monoacylated and diacylated monomeric (F1), trimeric (F3) and tetrameric (F4) forms of the intestinal protein were purified here for the first time by performing hydrophobic chromatography and gel filtration. The molecular mass of these three enzymatic forms was,estimated to be 60, 180 and 240 kDa, respectively, based on size-exclusion chromatography and SDS/PAGE analysis. The existence of a covalent attachment linking palmitate and myristate to porcine intestinal carboxylesterase (PICE), which was suggested by the results of gas-liquid chromatography (GLC) experiments in which the fatty acids resulting from alkali treatment of the protein forms were isolated, was confirmed here by the fact that [3H]palmitic and [3H]myristic acids were incorporated into porcine enterocytes and hepatocytes in cell primary cultures. Besides these two main fatty acids, the presence of oleic, stearic, and arachidonic acids was also detected by GLC and further confirmed by performing radioactivity counts on the 3H-labelled PICE forms after an immunoprecipitation procedure using specific polyclonal antibodies, followed by a SDS/PAGE separation step. Unlike the F1 and F4 forms, which were both myristoylated and palmitoylated, the F3 form was only palmitoylated. The monomeric, trimeric and tetrameric forms of PICE were all able to hydrolyse short chain fatty acids containing glycerides, as well as phorbol esters. The broad specificity of fatty acylated carboxylesterase is discussed in terms of its possible involvement in the metabolism of ester-containing xenobiotics and signal transduction. [source] Adhesion and development of the root rot fungus (Heterobasidion annosum) on conifer tissues: effects of spore and host surface constituentsFEMS MICROBIOLOGY ECOLOGY, Issue 2 2000Frederick O Asiegbu Abstract The objective of this study was to correlate the occurrence of particular root and woody stump surface components with the ability of spores of the root rot fungus (Heterobasidion annosum) to adhere, germinate and establish on conifer tissues. With the aid of high performance liquid chromatography, several sugars (pinitol, xylitol, dulcitol, mannitol, D -glucose, mannose, fructose) were detected on both stump and fine root surfaces of Scots pine and Norway spruce. Of all the sugars observed, xylose and arabinose were poorly utilized for initiation of germ tube growth whereas spore germination was enhanced in the presence of D -glucose, mannose or fructose. Oxidation of these sugars by pretreatment of wood discs or roots with periodic acid abolished the ability of the spores to germinate. Non-sugar components such as long chain fatty acids on spores and root surfaces as detected with nuclear magnetic resonance were found to have a significant influence on adhesion and initiation of germ tube development. Removal of these aliphatic compounds from the root surface increased spore germination by 2-fold, whereas similar treatment on spores led to a 5-fold decrease in adhesiveness to root material. In vitro studies revealed that the di-ethyl ether extract from the roots had no long term adverse effect on spore germination which suggests that the fungus may possess the capability to detoxify this substance. Similarly, adhesion of spores was affected by low and freezing temperatures. The role of significant levels of mannitol and trehalose accumulated in spores and hyphae of the fungi on viability, survival and tolerance to adverse conditions such as oxidative stress, freezing and desiccation are discussed. [source] Evaluation of supplementary stevia (Stevia rebaudiana, bertoni) leaves and stevioside in broiler diets: effects on feed intake, nutrient metabolism, blood parameters and growth performanceJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 6 2008J. O. Atteh Summary A perennial schrub, stevia, and its extracts are used as a natural sweetener and have been shown to possess antimicrobial properties. Stevia contains high levels of sweetening glycosides including stevioside which is thought to possess antimicrobial and antifungal properties. Little is known about the nutritional value of the schrub in livestock. This study determined the potential use of the shrub as a prebiotic animal feed supplement in light of the recent ban on the use of antibiotics in animal feed and the role of its constituent stevioside in the effects of the shrub. Male Cobb broiler chicks were fed a basal broiler diet without antibiotic but with performance enhancing enzyme mix (positive control), a basal diet without antibiotic and enzymes (negative control), or diets in which 2% of the negative control diet was replaced with either dried ground stevia leaves or 130 ppm pure stevioside during 2 week starter and 2 week grower periods. Body weight gains, feed conversion, abdominal fat deposition, plasma hormone and metabolites and caecal short chain fatty acids (SCFA) were measured in the broilers at 2 and 4 weeks of age. There was no significant effect of the treatments on feed intake during the starter period but birds fed diet supplemented with stevia leaves and stevioside consumed more feed (p < 0.05) than those fed the positive control diet during the grower period. Weight gain by birds fed the positive control and stevioside diets was higher (p < 0.05) than those fed other diets only during the starter period. Feed/gain ratio of birds fed the positive control and stevioside diets was superior (p < 0.05) to others. There was no effect of the treatments on nutrient retention and water content of the excreta. Dietary stevia leave and stevioside decreased total concentration of SCFA and changed their profile in the ceca. There was no effect of the treatments on pancreas weight. Dietary stevia reduced blood levels of glucose, triglycerides and triiodothyronine (T3) but had no effect on non-esterified fatty acids. In contrast, stevioside only decreased T3. Both the stevia leaves and stevioside diets significantly increased abdominal fat content. It is concluded that dietary enzyme growth promoters are beneficial to the broilers only during the starter stage and that inclusion of stevia leaves or stevioside has no beneficial effect on the performance of broilers. [source] The effect of short chain fatty acids on calcium flux rates across isolated rumen epithelium of hay-fed and concentrate-fed sheepJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2003S. K. Uppal Summary The present in vitro experiment was conducted to study the effect of two concentrations of short chain fatty acids [SCFA: 0 (control), 40 and 100 mmol/l in the buffer solution on mucosal side] on calcium ion (Ca2+) transport across the isolated rumen epithelium of two groups of sheep. One group was subjected to hay ad libitum, whereas the other to concentrate feed (800 g per day in equal portion at 7.00 and 15.00 hours and hay ad lib). The conventional Ussing chamber method was used for measuring the Ca2+ transport rates (45Ca), short-circuit current (Isc) and tissue conductance (GT) of isolated rumen epithelium. The SCFA significantly increased Isc of the epithelia of concentrate-fed sheep. In both hay- and concentrate-fed animals, 45Ca flux rates showed an almost linear increase in net flux rate () with rising concentrations of SCFA, as a result of a combined effect of a large increase in mucosal-to-serosal flux rates () and an almost linear, but small, decrease in serosal-to-mucosal flux rate (). In concentrate-fed sheep and were significantly higher in tissues incubated with SCFA compared with hay-fed animals. The well-known adaptable morphological and functional changes in the rumen epithelium attributable to concentrate feeding obviously include Ca2+ transport; such feeding therefore may be considered as a possible prophylactic measure in the prevention of milk fever. [source] INHIBITION OF MICROORGANISMS IN SALAD DRESSING BY SUCROSE AND METHYLGLUCOSE FATTY ACID MONOESTERSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2003CHING-MIAO YANG The antimicrobial activity of sucrose and methylglucose esters of medium to long chain fatty acids was studied with two microorganisms involved in the spoilage of salad dressings, Zygosaccharomyces bailii and Lactobacillus fructivorans. The microorganisms were inhibited to various degrees by 0.1, 0.5, and 1.0% synthesized sucrose or methylglucose monoesters using a modified broth dilution method. Sucrose monoesters were most inhibitory when the esterified fatty acid was myristic (C14) or palmitic acid (C16). Methylglucose monoesters with lauric (C12) or myristic acid (C14) exhibited greater inhibition than those with longer chain fatty acids. The least inhibition was generally observed with sucrose and methylglucose oleate (C18:1). Sucrose monoesters were usually more inhibitory than methylglucose monoesters of the same fatty acid, especially for palmitic and stearic (C18) acids. In salad dressing, 1% sucrose monoesters of lauric, myristic, or palmitic acid significantly (P < 0.05) inhibited the growth of Z. bailii and L. fructivorans, and were comparable with or more effective than 0.1% sodium benzoate. Z. bailii growth was nearly completely inhibited by sucrose laurate, myristate and palmitate by 9 days of salad dressing storage. Sucrose monoesters did not delay the lag phase of L. [source] Perioperative management of a child with short-chain acyl-CoA dehydrogenase deficiencyPEDIATRIC ANESTHESIA, Issue 9 2005BRIAN TURPIN BS Summary Short-chain acyl-CoA dehydrogenase (SCAD) is a mitochondrial enzyme that catalyzes the dehydrogenation of short chain fatty acids (4 to 6 carbons in length) thereby initiating the cycle of , -oxidation. This process generates acetyl-CoA, the key substrate for hepatic ketogenesis or ATP production by the Kreb's cycle. A deficiency of SCAD results in the build-up of potentially cytotoxic metabolites including ethylmalonic acid, methylsuccinyl CoA and butyryl-carnitine. The end-organ involvement is heterogeneous, but most commonly includes hypotonia with possible lipid myopathy and developmental delay. Other reported complications include dysmorphic craniofacial features, hypoglycemia, seizures, scoliosis, hypertonia and hyperreflexia, cyclic vomiting and myocardial dysfunction. We present a 23-month-old girl with SCAD deficiency, who required posterior fossa decompression for type 1 Chiari malformation. The potential perioperative implications of SCAD deficiency are reviewed. [source] Disorders of carnitine transport and the carnitine cycle,AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 2 2006Nicola Longo Abstract Carnitine plays an essential role in the transfer of long-chain fatty acids across the inner mitochondrial membrane. This transfer requires enzymes and transporters that accumulate carnitine within the cell (OCTN2 carnitine transporter), conjugate it with long chain fatty acids (carnitine palmitoyl transferase 1, CPT1), transfer the acylcarnitine across the inner plasma membrane (carnitine-acylcarnitine translocase, CACT), and conjugate the fatty acid back to Coenzyme A for subsequent beta oxidation (carnitine palmitoyl transferase 2, CPT2). Deficiency of the OCTN2 carnitine transporter causes primary carnitine deficiency, characterized by increased losses of carnitine in the urine and decreased carnitine accumulation in tissues. Patients can present with hypoketotic hypoglycemia and hepatic encephalopathy, or with skeletal and cardiac myopathy. This disease responds to carnitine supplementation. Defects in the liver isoform of CPT1 present with recurrent attacks of fasting hypoketotic hypoglycemia. The heart and the muscle, which express a genetically distinct form of CPT1, are usually unaffected. These patients can have elevated levels of plasma carnitine. CACT deficiency presents in most cases in the neonatal period with hypoglycemia, hyperammonemia, and cardiomyopathy with arrhythmia leading to cardiac arrest. Plasma carnitine levels are extremely low. Deficiency of CPT2 present more frequently in adults with rhabdomyolysis triggered by prolonged exercise. More severe variants of CPT2 deficiency present in the neonatal period similarly to CACT deficiency associated or not with multiple congenital anomalies. Treatment for deficiency of CPT1, CPT2, and CACT consists in a low-fat diet supplemented with medium chain triglycerides that can be metabolized by mitochondria independently from carnitine, carnitine supplements, and avoidance of fasting and sustained exercise. © 2006 Wiley-Liss, Inc. [source] Current Progress in the Fatty Acid Metabolism in Cryptosporidium parvum,THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 4 2004GUAN ZHU ABSTRACT Cryptosporidium parvum is one of the apicomplexans that can cause severe diarrhea in humans and animals. The slow development of anti-cryptosporidiosis chemotherapy is primarily due to the poor understanding on the basic metabolic pathways in this parasite. Many well-defined or promising drug targets found in other apicomplexans are either absent or highly divergent in C. parvum. The recently discovered apicoplast and its associated Type n fatty acid synthetic enzymes in Plasmodium, Toxoplasma, and Eimeria apicomplexans are absent in C. parvum, suggesting this parasite is unable to synthesize fatty acids de novo. However, C. parvum possesses a giant Type I fatty acid synthase (CpFASl) that makes very long chain fatty acids using mediate or long chain fatty acids as precursors. Cryptosporidium also contains a Type I polyketide synthase (CpPKSl) that is probably involved in the production of unknown polyketide(s) from a fatty acid precursor. In addition to CpFASl and CpPKSl, a number of other enzymes involved in fatty acid metabolism have also been identified. These include a long chain fatty acyl elongase (LCE), a cytosolic acetyl-CoA carboxylase (ACCase), three acyl-CoA synthases (ACS), and an unusual "long-type" acyl-CoA binding protein (ACBP), which allows us to hypothetically reconstruct the highly streamlined fatty acid metabolism in this parasite. However, C. parvum lacks enzymes for the oxidation of fatty acids, indicating that fatty acids are not an energy source for this parasite. Since fatty acids are essential components of all biomembranes, molecular and functional studies on these critical enzymes would not only deepen our understanding on the basic metabolism in the parasites, but also point new directions for the drug discovery against C. parvum and other apicomplexan-based diseases. [source] Novel physiological function of fructooligosaccharidesBIOFACTORS, Issue 1-4 2004Takahisa Tokunaga Abstract Two key properties of short chain fructooligosaccharides (sc-FOS) which lead to physiological functions are indigestibility in the small intestine and fermentability in the colon. Sc-FOS is converted into short chain fatty acids (SCFAs) by intestinal bacteria in the colon and absorbed. Through the metabolic pathway, sc-FOS improves gastrointestinal (GI) condition such as relief from constipation, formation of preferable intestinal microflora and intestinal immunomodulation those are known as prebiotics' function. Besides improvement of GI condition, dietary sc-FOS influences on calcium and magnesium absorption in the colon. A major mineral absorption site is the small intestine, but the colon also works as a Ca and Mg absorption site with an aid of SCFAs made from sc-FOS. Furthermore dietary sc-FOS influences on bioavailability of soy-isoflavones. Plasma and urinal concentration of Genistein and Daidzein, aglycones of Daidzin and Genistin, are higher in the rat fed with sc-FOS than the control rat. An additive effect of dietary isoflavone and sc-FOS was observed on the bone mineral density in OVX mice and moreover sc-FOS increased ceacal ,-glycosidase activity and equol production. These results suggest that FOS increase the bioavailability of isoflavones. [source] Lipase catalyzed synthesis of ester-based surfactants from biomass derivativesBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 2 2008Sanjib Kumar Karmee Abstract Non-ionic surfactants find a unique place in pharmaceutical, detergent, food, and cosmetic industries because of their ready availability from biomass, low cost, and renewability. Generally these surfactants are esters obtained from the reaction of glycerol, L-ascorbic acid, and sugar, with long or medium chain fatty acids. Problems encountered during the synthesis of these surfactants are the immiscibility of highly polar substrates in organic solvents and non-regioselective reaction. Therefore, lipases as a catalyst and t -butanol or acetone, a mixture of solvent and ionic liquid as solvents, have been used for the synthesis of ester-based surfactants. This review focuses on the uses of lipases for the synthesis of surfactants obtained from biomass derivatives viz. fats and oils, sugar and vitamin-C. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd [source] Metabolic Carbon Fluxes and Biosynthesis of Polyhydroxyalkanoates in Ralstonia eutropha on Short Chain Fatty AcidsBIOTECHNOLOGY PROGRESS, Issue 4 2004Jian Yu Short chain fatty acids such as acetic, propionic, and butyric acids can be synthesized into polyhydroxyalkanoates (PHAs) by Ralstonia eutropha. Metabolic carbon fluxes of the acids in living cells have significant effect on the yield, composition, and thermomechanical properties of PHA bioplastics. Based on the general knowledge of central metabolism pathways and the unusual metabolic pathways in R. eutropha,a metabolic network of 41 bioreactions is constructed to analyze the carbon fluxes on utilization of the short chain fatty acids. In fed-batch cultures with constant feeding of acid media, carbon metabolism and distribution in R. eutropha were measured involving CO2, PHA biopolymers, and residual cell mass. As the cells underwent unsteady state metabolism and PHA biosynthesis under nitrogen-limited conditions, accumulative carbon balance was applied for pseudo-steady-state analysis of the metabolic carbon fluxes. Cofactor NADP/NADPH balanced between PHA synthesis and the C3/C4 pathway provided an independent constraint for solution of the underdetermined metabolic network. A major portion of propionyl-CoA was directed to pyruvate via the 2-methylcitrate cycle and further decarboxylated to acetyl-CoA. Only a small amount of propionate carbon (<15% carbon) was directly condensed with acetyl-CoA for 3-hydroxyvalerate. The ratio of glyoxylate shunt to TCA cycle varies from 0 to 0.25, depending on the intracellular acetyl-CoA level and acetic acid in the medium. Malate is the node of the C3/C4 pathway and TCA cycle and its decarboxylation to dehydrogenation ranges from 0.33 to 1.28 in response to the demands on NADPH and oxaloacetate for short chain fatty acids utilization. [source] N -Acyl amino acids and N -acyl neurotransmitter conjugates: neuromodulators and probes for new drug targetsBRITISH JOURNAL OF PHARMACOLOGY, Issue 8 2010Mark Connor The myriad functions of lipids as signalling molecules is one of the most interesting fields in contemporary pharmacology, with a host of compounds recognized as mediators of communication within and between cells. The N -acyl conjugates of amino acids and neurotransmitters (NAANs) have recently come to prominence because of their potential roles in the nervous system, vasculature and the immune system. NAAN are compounds such as glycine, GABA or dopamine conjugated with long chain fatty acids. More than 70 endogenous NAAN have been reported although their physiological role remains uncertain, with various NAAN interacting with a low affinity at G protein coupled receptors (GPCR) and ion channels. Regardless of their potential physiological function, NAAN are of great interest to pharmacologists because of their potential as flexible tools to probe new sites on GPCRs, transporters and ion channels. NAANs are amphipathic molecules, with a wide variety of potential fatty acid and headgroup moieties, a combination which provides a rich source of potential ligands engaging novel binding sites and mechanisms for modulation of membrane proteins such as GPCRs, ion channels and transporters. The unique actions of subsets of NAAN on voltage-gated calcium channels and glycine transporters indicate that the wide variety of NAAN may provide a readily exploitable resource for defining new pharmacological targets. Investigation of the physiological roles and pharmacological potential of these simple lipid conjugates is in its infancy, and we believe that there is much to be learnt from their careful study. [source] Faecal short chain fatty acid pattern and allergy in early childhoodACTA PAEDIATRICA, Issue 5 2009Anna Sandin Abstract Aim: To investigate whether functional changes of the gut flora over time were related to sensitization and allergic symptoms at four years of age. Methods: The levels of short chain fatty acids (SCFAs) in faecal samples at one (n = 139) and four (n = 53) years of age were related to the development of positive skin prick tests (SPT) and allergic symptoms during the first four years of life. Results: Faecal acetic (p < 0.01) and propionic (p < 0.01) acids decreased from one to four years of age, while valeric acid (p < 0.001) increased. Low levels of i-butyric (p = 0.01), i-valeric (p = 0.03) and valeric acids (p = 0.02) at one year were associated with questionnaire-reported symptoms of food allergy at four years. Positive SPTs and allergic symptoms at four years were associated with low faecal levels of i-butyric, i-valeric and valeric acids. At one year of age, infants with, as compared to without older siblings had higher median levels of valeric acid. Conclusion: A slow functional maturation of the gut microflora, as measured by faecal levels of SCFAs is associated with allergy both at one and four years. The findings lend further support to an association between allergy and the development of microbial diversity. [source] | ||||||||||||||||