Synthesis and metabolism of arachidonyl- and eicosapentaenoyl-CoA in rat aorta

In studies on the metabolism of polyunsaturated fatty acids, acyl-CoA synthetase for 5,8,11,14-20:4 (arachidonic acid) and 5,8,11,14,17-20:5 (eicosapentaenoic acid) and the incorporation of these fatty acids into complex lipids and their conversion to CO2 were investigated in rat aorta. The activity of acyl-CoA synthetase was 35.9 for arachidonic acid and 63.0 for eicosapentaenoic acid (nmol/mg protein per 10 min) and the apparent Km values were 45 microM for arachidonic acid and 56 microM for eicosapentaenoic acid. Inhibition of eicosapentaenoyl-CoA synthesis by arachidonic acid was stronger than that of arachidonyl-CoA synthesis by eicosapentaenoic acid. Arachidonic acid and eicosapentaenoic acid were mostly incorporated into phospholipids. The incorporation of these fatty acids into cholesterol ester and their conversion to CO2 were less than those of palmitic acid, but their incorporation into triacyglycerol was greater. The incorporation of these fatty acids into phosphatidylserine + phosphatidylinositol and phosphatidylethanolamine was also greater than that of palmitic acid. The patterns of incorporation of arachidonic acid and eicosapentaenoic acid were similar. The physiological roles of these polyunsaturated fatty acids and the interference of eicosapentaenoic acid in arachidonic acid metabolism are discussed on the basis of these results.     

Aromatic and fatty acids of triterpene esters and rubber content of Hoya latices and their taxonomic significance

The acid composition and the rubber content of the latices of 20 Hoya species were determined. All acids isolated from the latices were esterified with triterpenols and particle-bound. Cinnamic acid was the main acid in most latices. Acetic acid occurred in all latices, and predominated in three of the investigated species. Isovaleric acid and benzoic acid were present in some species; in one latex (H. bella) isovaleric acid was the predominant acid. Almost all species contained small amounts of phenylpropionic acid, and in two species this acid was a major compound. Longchain fatty acids were present as minor compounds. Rubber occurred in all particle-containing latices; its contribution to the total lipid fraction ranged from 1.7–24.0%. The acid profiles proved to be species-specific in Hoya and may be useful in species identification. Patterns of latex particle synthesis are proposed.     

Synthesis and Antiviral Activity of Ureides and Carbamates of Betulinic Acid and Its Derivatives

Ureides and carbamates of betulinic acid and its derivatives were prepared in good yields by interaction of betulinic acid, betulonic acid, and betulonic acid 3-oxime with amines, amino acids, and alcohols. Ureides of betulonic acid containingL-Val and L-Met residues were found to be effective against herpes simplex type 1 virus.     

Sterol and bile acid metabolism during development. 1. Studies on the gallbladder and intestinal bile acids of newborn and fetal rabbit

Bile acid composition and content in the intestine and gallbladder of newborn and fetal rabbits were investigated. Unlike the circumstances in adult rabbits, the bile acids were conjugated with both taurine and glycine. The major bile acids of the fetus and newborn rabbit were cholic acid, chenodeoxycholic acid, and deoxycholic acid. This is different from the known bile acid composition of adult rabbits, in which deoxycholic acid is the major bile acid (> 80%). The proportion of chenodeoxycholic acid was higher in the fetal than in the newborn tissues. The total bile acid pool in the newborn was higher than in the fetus. In the fetus, large proportions of bile acids (60.9%) were associated with the gallbladder fraction, whereas in the newborn the bulk of the bile acids were found with the intestinal fraction (64.4%),     

浓香型白酒窖泥中可培养细菌的分离鉴定及产酸研究

为系统了解浓香型白酒窖泥中可培养细菌的多样性,采用平板稀释涂布法分离筛选窖泥中可培养菌株。扩增纯培养细菌的16SrRNA基因,测序并与EzBioCloud数据库比对,所有序列已在GenBank中注册。结果共从窖泥中筛选出42株差异性较大的菌株,其中5株与模式菌株相似性低于97％,共包括14个属,以Bacillus、Lysinibacillus、Sporosarcina、Staphylococcus四个属为主;高效液相色谱检测各个菌发酵液结果表明,有机酸包括乙酸、乳酸、酒石酸、苹果酸、柠檬酸、琥珀酸、α-酮戊二酸、草酸;其中尤以乙酸、乳酸的产量较高。     

Synthesis and antiviral activity of hydrazides and substituted benzalhydrazides of betulinic acid and its derivatives

New nitrogen-containing derivatives of betulinic and betulonic acids, hydrazides and N'-benzalhydrazides, were synthesized. Their antiviral activities toward of influenza A virus, herpes simplex type I virus, enterovirus ECHO6, and HIV-1 were studied in vitro. Betulinic acid 3-oxime was found to have the highest activity against the influenza virus. Betulonic acid, betulinic acid 4-chlorobenzalhydrazide, betulonic acid 3-oxime benzalhydrazide, and betulinic acid hydrazide inhibited the replication of herpes simplex type I virus. Betulinic acid hydrazide also showed antiviral activity toward HIV-1. All the derivatives of betulinic acid under study displayed a low antiviral activity toward enterovirus ECHO6.     

Synthesis and antiviral activity of ureides and carbamates of betulinic acid and its derivatives

Ureides and carbamates of betulinic acid and its derivatives were prepared in good yields by interaction of betulinic acid, betulonic acid, and betulonic acid 3-oxime with amines, amino acids, and alcohols. Ureides of betulonic acid containing L-Val and L-Met residues were found to be effective against herpes simplex type 1 virus. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2003, vol. 29, no. 6; see also http://www.maik.ru.     

Isolation and characterisation of bis-phosphatidic acid and its partially deacylated derivatives from cultured BHK-cells

Bis-phosphatidic acid, semi-lyso-bis-phosphatidic acid and lyso-bis-phosphatidic acid were isolated from cultured baby hamster kidney fibroblasts (BHK-cells). They constituted about 0.02%, 0.1% and 1.6% respectively of total lipid phosphorus of fresh BHK-cell monolayers. These three phospholipids were also prepared by partial synthesis. The natural lipids were identical with the synthetic samples as determined by thin-layer chromatography and by partial degradation by controlled alkaline methanolysis, acetic acid hydrolysis and acetolysis. The three derivatives of bis-phosphatidic acid contained 60–80% of octadecenoic acid; in this respect they were different from other BHK-cell phospholipids.     

The reaction of hyaluronic acid and its monomers, glucuronic acid and N-acetylglucosamine, with reactive oxygen species

Synovial fluid is a approximately 0.15% (w/v) aqueous solution of hyaluronic acid (HA), a polysaccharide consisting of alternating units of GlcA and GlcNAc. In synovial fluid of patients suffering from rheumatoid arthritis, HA is thought to be degraded either by radicals generated by Fenton chemistry (Fe2+/H2O2) or by NaOCl generated by myeloperoxidase. We investigated the course of model reactions of these two reactants in physiological buffer with HA, and with the corresponding monomers GlcA and GlcNAc. meso-Tartaric acid, arabinuronic acid, arabinaric acid and glucaric acid were identified by GC-MS as oxidation products of glucuronic acid. When GlcNAc was oxidised, erythronic acid, arabinonic acid, 2-acetamido-2-deoxy-gluconic acid, glyceric acid, erythrose and arabinose were formed. NaOCl oxidation of HA yielded meso-tartaric acid; in addition, arabinaric acid and glucaric acid were obtained by oxidation with Fe2+/H2O2. These results indicate that oxidative degradation of HA proceeds primarily at glucuronic acid residues. meso-Tartaric acid may be a useful biomarker of hyaluronate oxidation since it is produced by both NaOCl and Fenton chemistry.     

Synthesis and Antiviral Activity of Hydrazides and Substituted Benzalhydrazides of Betulinic Acid and Its Derivatives

New nitrogen-containing derivatives of betulinic and betulonic acids, hydrazides and N"-benzalhydrazides, were synthesized. Their antiviral activities toward viruses of influenza A virus, herpes simplex type I virus, enterovirus ECHO6, and HIV-1 were studied in vitro. Betulinic acid 3-oxime was found to have the highest activity against the influenza virus. Betulonic acid, betulinic acid 4-chlorobenzalhydrazide, betulonic acid 3-oxime benzalhydrazide, and betulinic acid hydrazide inhibited the replication of herpes simplex type I virus. Betulinic acid hydrazide also showed antiviral activity toward HIV-1. All the derivatives of betulinic acid under study displayed a low antiviral activity toward enterovirus ECHO6.     

Bile formation and hepatic plasma membrane composition in guinea-pigs and rats

We compared bile formation, and biliary and liver plasma membrane composition in guinea-pigs and rats in an attempt to explain the observation that the bile flow rate and the bile acid independent fraction of bile flow (BAIF) in guinea-pigs is about five to seven times higher than in rats. Analysis of electrolytes in bile showed that bicarbonate was significantly [acid] higher in guinea-pigs while Cl⁻, phosphate and Ca²⁺ were markedly lower than in rats. High bile independent secretion in guinea-pigs was associated with a significantly lower concentration of total bile acid, phospholipid and cholesterol than in rats. Bile acid distribution studies showed that glycine conjugated chenodeoxycholate and ketolithocholate were the main bile acids in guinea-pigs, while taurine conjugated cholate and muricholate were the predominant bile acids in rats. Total fatty acid analysis of bile indicated that in rats the major fatty acids were palmitic acid (C16:0) and linoleic acid (C18:2, n-6). In guinea-pigs, the contribution of these fatty acids was lower than in rats and compensated with a significantly higher percentage of oleic acid (C18:1, n-9). Concentrations of anionic polypeptide fraction (APF), an acidic calcium binding apoprotein closely associated with biliary phospholipid and cholesterol secretion was also significantly lower in guinea-pigs. Canalicular plasma membrane analysis showed that as compared with rats, specific activities of Na⁺,K⁺ ATPase, and cholesterol and phospholipid content were markedly lower in guinea-pigs. Total fatty acid analysis of the membrane revealed that palmitic acid (C16:0), stearic acid (C18:0) and linoleic acid (C18:2, n-6) were the predominant fatty acids in guinea-pigs, while palmitic acid (C16:0), stearic acid (C18:0) and arachidonic acid (C20:4, n-6) were the most important in rats. Thus, high bile flow rate and BAIF in the guinea-pig may be attributed to the low bile acid concentration (below the critical micellar concentration), secretion of hypercholeretic bile acids (e.g. ketolithocholate) and high bicarbonate output.     

Chloroperoxidase-catalyzed halogenation of trans-cinnamic acid and its derivatives

Several 2,3-unsaturated carboxylic acids, such as trans-cinnamic acid and its derivatives, were found to be halogenated by chloroperoxidase of Caldariomyces fumago in the presence of hydrogen peroxide and either Cl- or Br-. Cinnamic acid, 4-hydroxycinnamic acid, 4-methoxycinnamic acid, and 3,4-dimethoxycinnamic acid were suitable substrates of chloroperoxidase, and were converted to 2-halo-3-hydroxycarboxylic acid, 2,3-dihydroxycarboxylic acid, decarboxylated halohydrin, or decarboxylated halocompound. However, 4-nitrocinnamic acid and 4-chlorocinnamic acid having electron-attracting groups did not serve as a substrate of the enzyme. The enzyme also did not act on acrylic acid, acrylamide, crotonic acid, fumaric acid, etc. From these data, the enzymatic reactions of chloroperoxidase, concerning the substrate specificity, stereoselectivity, and the reaction mechanism, are discussed on the basis of current knowledge regarding the reaction mechanism of the enzyme. Also they are compared with the chemical reactions of molecular halogen and hypohalous acid.     

N-acetylneuraminic acid and N-glycolylneuraminic acid in glycopeptides of colonic tumor and mucosa in rats treated with carrageenan and 1,2-dimethylhydrazine

N-linked glycopeptides were prepared from colonic tumor (adenocarcinoma) and mucosa in rats treated with carrageenan, an indigestible polysaccharide, and 1,2-dimethylhydrazine. Sialic acids, N-acetylneuraminic acid and N-glycolylneuraminic acid, obtained by acid hydrolysis of the glycopeptides were determined by HPLC. The N-acetylneuraminic acid/N-glycolylneuraminic acid ratio in colonic tumor was 25.2, while each treated mucosa had the values between 0.29 and 0.55. Thus, necessity which observes the qualitative change of sialic acid in malignant transformation was suggested.     

Growth inhibition of selected food-borne bacteria by tannic acid, propyl gallate and related compounds

Tannic acid, propyl gallate, gallic acid and ellagic acid were tested for their inhibitory effects on selected food-borne bacteria by the well assay technique. Tannic acid and propyl gallate were inhibitory whereas gallic acid and ellagic acid were not.     

金刺梨果实和叶中酚类、Vc含量及其抗氧化能力分析

为了解贵州金刺梨（Rosa sterilis D.Shi）果实和叶片中的活性成分及其抗氧化活性,以贵州普定县金刺梨种植基地的果实和叶片为试材,测定其活性成分含量及其抗氧化活性,并对各项指标进行相关性分析。结果显示：没食子酸、芦丁、槲皮素、儿茶素、鞣花酸、绿原酸、阿魏酸是供试金刺梨果实和叶片的主要酚类成分,金刺梨果实和叶片中活性组分差异显著（P<0.05）,果实中p-香豆酸、总黄酮和抗坏血酸的含量相对较高,而叶片中没食子酸、儿茶素、绿原酸、表儿茶素、阿魏酸、鞣花酸、芦丁、槲皮素和总酚含量均高于果实;金刺梨果实抗氧化活性值均显著高于叶片（P<0.05）;相关性分析发现：总黄酮对总还原力（TRPA）值的贡献极强,抗坏血酸对Fe³⁺还原抗氧化能力（FRAP）值贡献最强,槲皮素对ABTS值的贡献最强,说明金刺梨果实和叶片是一种具有较高开发价值的药食同源资源。     

Characterization of hen egg white- and yolk-riboflavin binding proteins and amino acid sequence of egg white-riboflavin binding protein

White- and Yolk-riboflavin binding proteins were isolated from hen eggs, and characterized as to their chemical properties. White- and Yolk-RBPs had almost same amino acid compositions except for glutamic acid, but their carbohydrate compositions were different from each other. The complete amino acid sequence of White-RBP was determined by conventional methods. White-RBP comprised 219 amino acid residues, and the amino-terminus was pyroglutamic acid (pyrrolidonecarboxylic acid). Two amino acids, lysine and asparagine, were found at the fourteenth residue from the amino-terminus. Carbohydrate chains were linked to asparagine residues at positions 36 and 147. Both White- and Yolk-RBPs were phosphorylated. In White-RBP either six or seven of nine serine residues between Ser(185) and Ser(197) were phosphorylated. The amino acid sequences around phosphoserines showed that phosphorylation might occur at a serine residue in one of the following sequences; Ser-X-Glu or Ser-X-Ser(P).     

Microbiological and physicochemical characterization of small-scale cocoa fermentations and screening of yeast and bacterial strains to develop a defined starter culture

Spontaneous cocoa bean fermentations performed under bench- and pilot-scale conditions were studied using an integrated microbiological approach with culture-dependent and culture-independent techniques, as well as analyses of target metabolites from both cocoa pulp and cotyledons. Both fermentation ecosystems reached equilibrium through a two-phase process, starting with the simultaneous growth of the yeasts (with Saccharomyces cerevisiae as the dominant species) and lactic acid bacteria (LAB) (Lactobacillus fermentum and Lactobacillus plantarum were the dominant species), which were gradually replaced by the acetic acid bacteria (AAB) (Acetobacter tropicalis was the dominant species). In both processes, a sequence of substrate consumption (sucrose, glucose, fructose, and citric acid) and metabolite production kinetics (ethanol, lactic acid, and acetic acid) similar to that of previous, larger-scale fermentation experiments was observed. The technological potential of yeast, LAB, and AAB isolates was evaluated using a polyphasic study that included the measurement of stress-tolerant growth and fermentation kinetic parameters in cocoa pulp media. Overall, strains L. fermentum UFLA CHBE8.12 (citric acid fermenting, lactic acid producing, and tolerant to heat, acid, lactic acid, and ethanol), S. cerevisiae UFLA CHYC7.04 (ethanol producing and tolerant to acid, heat, and ethanol), and Acetobacter tropicalis UFLA CHBE16.01 (ethanol and lactic acid oxidizing, acetic acid producing, and tolerant to acid, heat, acetic acid, and ethanol) were selected to form a cocktail starter culture that should lead to better-controlled and more-reliable cocoa bean fermentation processes.     

Influence of sex and gonadal hormones on rat-liver and carcass lipids during the development of an essential fatty acid deficiency

1. Groups of intact male and female rats and castrated rats injected with oestradiol or testosterone were given a diet containing hydrogenated coconut oil for 9 weeks, and at intervals the amounts and fatty acid compositions of the carcass and liver lipids were determined. 2. Male rats grew faster and larger, and exhibited typical external essential fatty acid deficiency symptoms sooner than did females. Testosterone-treated castrated male rats were similar to males, and oestradiol-injected castrated male rats resembled females. 3. Intact females maintained a higher linoleic acid concentration in their carcass than did males. Total amounts of carcass linoleic acid remained similar for all groups, only 200mg. being removed in 9 weeks regardless of body size. 4. The amounts of total cholesteryl esters were independent of liver size. They were higher in males and testosterone-treated castrated male rats than in females and oestrogen-treated castrated male rats. 5. Phospholipids represented about 80% of the liver lipids. The total amounts of the phospholipid linoleic acid and arachidonic acid were similar for all groups regardless of liver size, and were not affected appreciably by the deficiency. Females and oestrogen-treated castrated male rats maintained a higher proportion of phospholipid arachidonic acid for longer periods than did their male counterparts. Both the total amounts and the proportions of eicosatrienoic acid and palmitic acid were higher in males than in females. 6. Supplementation of the essential fatty acid-deficient diet with linoleic acid caused a rapid loss of eicosatrienoic acid and palmitic acid with a concomitant increase in stearic acid and arachidonic acid. 7. There were no obvious differences in the way that the essential fatty acids were metabolized or mobilized from adipose tissue of male or female rats during essential fatty acid deficiency. 8. The results indicated that the greater growth rate of the male rats caused them to require and synthesize more phospholipids than did the females. In the absence of adequate amounts of arachidonic acid, eicosatrienoic acid was substituted into the additional phospholipid. The earlier symptoms of essential fatty acid deficiency in the male rat could therefore be ascribed to the higher tissue concentrations of this unnatural phospholipid and its inability to perform the normal metabolic functions of phospholipids.     

Analysis of major tomato xylem organic acids and PITC-derivatives of amino acids by RP-HPLC and UV detection

Major amino acids and organic acids in xylem exudates of tomato plants were separated by reversed phase high performance liquid chromatography (RP-HPLC) and quantified by UV detection. Before separation, amino acids were converted into their phenylisothiocyanate (PITC) derivatives. In a single run, Asp, Glu, Ser, Gln, His, Thr, Ala, Tyr, Val, Met, Cys, Ile, Leu, Phe, and Lys could be separated and detected down to the pmol level. Unresolved peaks were obtained for Asn and Gly and for Arg and Pro. For organic acid analysis, exudates were pre-treated by perfusion over a prepacked Adsorbex SCX cation exchange column, to eliminate exudate amino acids. Elution recoveries for organic acids were close to 100%. The exudate organic acids were separated by ion suppression RP-HPLC chromatography, and peaks could be resolved for L-malic acid, malonic acid, maleic acid, citric acid and fumaric acid, down to the pmol level. UV signals for exudate ascorbic acid, and succinic acid were below the limits of detection. Determination of oxalic acid and tartaric acid was impossible, due to the presence of the exudate salt peak in the chromatogram. The results indicate the potential of the methods applied, and show the applicability of RP-HPLC analysis for the determination of both amino acids and organic acids in xylem exudates.     

Fed-batch fermentation with and without on-line extraction for propionic and acetic acid production byPropionibacterium acidipropionici

Fed-batch propionic and acetic acid fermentations were performed in semi-defined laboratory medium and in corn steep liquor withPropionibacterium acidipropionici strain P9. On average, over four experiments, 34.5 g/l propionic acid and 12.8 g/l acetic acid were obtained in about 146 h in laboratory medium with 79 g/l glucose added over five feeding periods. The highest concentration of propionic acid, 45 g/l, was obtained when the glucose concentration was not allowed to drop to zero. In corn steep liquor 35 g/l propionic acid and 11 g/l acetic acid were produced in 108 h from 59.4 g/l total lactic acid provided as seven feedings of corn steep liquor. Extractive fed-batch fermentations were conducted in semi-defined medium using either flat-sheet-supported liquid membranes or hollow-fiber membrane extraction to remove organic acids from the culture medium. As operated during the course of the fermentation, these systems extracted 25% and 22% of the acetic acid and 36.5% and 44.5% of the propionic acid, respectively, produced in the fermentation. Total amounts of acids produced were about the same as in comparable nonextractive fermentations: 30–37 g/l propionic acid and 13 g/l acetic acid were produced in 150 h. Limitations on acid production can be attributed to limited substrate feed, not to failure of the extraction system.Journal paper J-16303 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project 3122.