Metabolite profiles of lactic acid bacteria in grass silage

The metabolite production of lactic acid bacteria (LAB) on silage was investigated. The aim was to compare the production of antifungal metabolites in silage with the production in liquid cultures previously studied in our laboratory. The following metabolites were found to be present at elevated concentrations in silos inoculated with LAB strains: 3-hydroxydecanoic acid, 2-hydroxy-4-methylpentanoic acid, benzoic acid, catechol, hydrocinnamic acid, salicylic acid, 3-phenyllactic acid, 4-hydroxybenzoic acid, (trans, trans)-3,4-dihydroxycyclohexane-1-carboxylic acid, p-hydrocoumaric acid, vanillic acid, azelaic acid, hydroferulic acid, p-coumaric acid, hydrocaffeic acid, ferulic acid, and caffeic acid. Among these metabolites, the antifungal compounds 3-phenyllactic acid and 3-hydroxydecanoic acid were previously isolated in our laboratory from liquid cultures of the same LAB strains by bioassay-guided fractionation. It was concluded that other metabolites, e.g., p-hydrocoumaric acid, hydroferulic acid, and p-coumaric acid, were released from the grass by the added LAB strains. The antifungal activities of the identified metabolites in 100 mM lactic acid were investigated. The MICs against Pichia anomala, Penicillium roqueforti, and Aspergillus fumigatus were determined, and 3-hydroxydecanoic acid showed the lowest MIC (0.1 mg ml(-1) for two of the three test organisms).     

Abnormal urinary bile acids in a patient suffering from cerebrotendinous xanthomatosis during oral administration of ursodeoxycholic acid

The urinary bile acid profile, obtained by capillary gas chromatography, of a patient suffering from cerebrotendinous xanthomatosis and treated with ursodeoxycholic acid demonstrated, besides the occurrence of 23-norcholic acid and (23R)-hydroxycholic acid (as a consequence of this disease), six additional unknown bile acids and three known bile acids, viz. ursodeoxycholic acid, hyocholic acid and omega-muricholic acid. The structure of two of the unknown bile acids were elucidated and proven by organic syntheses. These were 23-norursodeoxycholic acid and 3 beta-ursodeoxycholic acid. The structures of three bile acids were tentatively elucidated as being 1 beta-hydroxyursodeoxycholic acid, 21-hydroxyursodeoxycholic acid and 22-hydroxyursodeoxycholic acid, and the possibility that the structure of the remaining bile acid is that of 5-hydroxyursodeoxycholic acid is discussed. Two of these bile acids (1 beta-hydroxyursodeoxycholic acid and 5-hydroxyursodeoxycholic acid) also occurred in urine of a healthy individual during oral ursodeoxycholic acid treatment, whereas 23-norcholic acid, 23-norursodeoxycholic acid, (23R)-hydroxycholic acid, 21-hydroxyursodeoxycholic acid and 22-hydroxyursodeoxycholic acid were only present in urine of the patient suffering from cerebrotendinous xanthomatosis. The metabolism of ursodeoxycholic acid, both in the normal state and in the cerebrotendinous xanthomatosis, is discussed.     

Bile acid profiles in bile, urine, and feces of a patient with cerebrotendinous xanthomatosis

Bile acid profiles of bile, urine, and feces obtained from a patient with cerebrotendinous xanthomatosis on the same day have been analyzed by gas-liquid chromatography-mass spectrometry after fractionation into groups by mode of conjugation by an ion-exchange chromatography. The predominant biliary bile acid was cholic acid conjugated with glycine and taurine. Lesser amounts of the amino acid conjugates of chenodeoxycholic acid, ursodeoxycholic acid, 7-ketodeoxycholic acid, allocholic acid, and deoxycholic acid, and of unconjugated norcholic acid and allonorcholic acid were also present in the bile. The major fecal bile acid was 7-epicholic acid. Relatively large amounts of bile acids were excreted in the urine. Unconjugated 7-epicholic acid, norcholic acid, allonorcholic acid, and cholic acid predominated. The bile acid profiles of the patient were different from those of normal subjects and should be useful for the diagnosis.     

羚牛肉、脂、蹄腺分泌物的生化分析

人类对于大型偶蹄类动物的利用已有较多先例,北美麝牛(Ovibous muschtus)近年在加拿大、美国等已经驯养,并以其毛绒作为一种特殊的毛丝工业原料。美洲野牛(Bison Americasus)已与家牛杂交生产肉用牛。我国青藏高原的牦牛(Bos grinus)与黄牛杂交而成的犏牛,已成为藏民的主要肉乳兼用牛。羚牛(Budorcas taxicolor)系稀有动物,为亚洲特产,分布于中国、印度、缅甸及不丹。中国的羚牛分布于川、陕、甘、滇、藏5省区,为分布区最广、数量最多、资源量丰富的国家(Wu,1985)。     

Intestinal microflora and bile acids. Effect of bile acids on the distribution of microflora and bile acid in the digestive tract of the rat

The population levels of intestinal microflora and bile acid composition in the digestive tract were examined in rats fed bile acids to determine the relationships between gastrointestinal microflora and the host. The population level of Bacteroides was increased in the ceca of rats fed cholic acid or deoxycholic acid. In the ileum, the concentration of conjugated bile acid in rats fed cholesterol, cholic acid, hyodeoxycholic acid or lithocholic acid was higher than that in control rats, and was very low in ceca and feces of all the rats. The concentration of total free bile acid was much higher in the ceca than in the ilea of rats fed hyodeoxycholic acid or lithocholic acid. Cholic acid and deoxycholic acid were found in the ilea, ceca and feces of the cholic acid-fed rats. In the deoxycholic acid-fed rats, cholic acid was localized in the ileum. 7-Ketodeoxycholic acid was also found in the ceca of the cholic acid-fed rats. 12-Ketolithocholic acid was found in the feces of rats fed cholic acid or deoxycholic acid. 3-Ketocholanic acid was found in some samples from the lithocholic acid-fed rats. Therefore, some kinds of bile acids influence the population levels of gastrointestinal microflora and bile acid composition in the intestine.     

The metabolism of n-decane by a Pseudomonas

The growth of a Pseudomonas on n-decane was found to produce stearic acid, oleic acid, palmitic acid, palmitoleic acid, decanoic acid, octanoic acid, beta-hydroxydecanoic acid, beta-hydroxyoctanoic acid, beta-hydroxyhexanoic acid and beta-hydroxyadipic acid. Small amounts of n-decanamide and n-valeramide were also isolated. The effects of nitrogen and oxygen limitation on the formation of these products in continuous fermentations is reported.     

Changes in free fatty acids of awamori during aging

The fatty acid components of awamori during aging were as follows. The total amount of volatile acids calculated as acetic acid ranged from 20 to 140 mg/l, the main acid was acetic acid, and the proportion of acetic acid to total acids ranged from 35 to 80 per cent. The main acids other than acetic acid were propionic acid and i-butyic acid. Differences were observed in fatty acid constituents between awamori and other alcoholic beverages.Certain components tended to increase during maturation in kame (porous earth-enware pots): acetic acid, i-butyric acid, i-valeric acid, valeric acid, capric acid, lauric acid, myristic acid and total fatty acids. Others, however, showed no distinct changes: propionic acid, butyric acid, caproic acid, caprylic acid, palmitic acid, stearic acid, oleic acid and linoleic acid.During maturation in non-porous containers (stainless-steel or glass-linked tanks), on the other hand, caprylic acid, capric acid, lauric acid and myristic acid components tended to increase, while no distinct changes however were shown by acetic acid, propionic acid, i-butyric, butyric acid, i-valeric acid, valeric acid, caproic acid, palmitic acid, stearic acid, oleic acid, linoleic acid and total fatty acids.     

Metabolite Profiles of Lactic Acid Bacteria in Grass Silage

The metabolite production of lactic acid bacteria (LAB) on silage was investigated. The aim was to compare the production of antifungal metabolites in silage with the production in liquid cultures previously studied in our laboratory. The following metabolites were found to be present at elevated concentrations in silos inoculated with LAB strains: 3-hydroxydecanoic acid, 2-hydroxy-4-methylpentanoic acid, benzoic acid, catechol, hydrocinnamic acid, salicylic acid, 3-phenyllactic acid, 4-hydroxybenzoic acid, (trans, trans)-3,4-dihydroxycyclohexane-1-carboxylic acid, p-hydrocoumaric acid, vanillic acid, azelaic acid, hydroferulic acid, p-coumaric acid, hydrocaffeic acid, ferulic acid, and caffeic acid. Among these metabolites, the antifungal compounds 3-phenyllactic acid and 3-hydroxydecanoic acid were previously isolated in our laboratory from liquid cultures of the same LAB strains by bioassay-guided fractionation. It was concluded that other metabolites, e.g., p-hydrocoumaric acid, hydroferulic acid, and p-coumaric acid, were released from the grass by the added LAB strains. The antifungal activities of the identified metabolites in 100 mM lactic acid were investigated. The MICs against Pichia anomala, Penicillium roqueforti, and Aspergillus fumigatus were determined, and 3-hydroxydecanoic acid showed the lowest MIC (0.1 mg ml⁻¹ for two of the three test organisms).     

Quinolinic acid, alpha-picolinic acid, fusaric acid, and 2,6-pyridinedicarboxylic acid enhance the Fenton reaction in phosphate buffer.

Quinolinic acid, alpha-picolinic acid, fusaric acid, and 2,6-pyridinedicarboxylic acid enhanced the Fenton reaction in phosphate buffer, respectively. The enhancement by quinolinic acid, alpha-picolinic acid, fusaric acid, and 2,6-pyridinedicarboxylic acid of the Fenton reaction may be partly related to their respective actions in the biological systems such as a neurotoxic effect (quinolinic acid), a marked growth-inhibitory action on rice seeding (alpha-picolinic acid and fusaric acid), and an antiseptic (2,6-pyridinedicarboxylic acid). The ultraviolet-visible absorption spectrum of the mixture of alpha-picolinic acid with ferrous ion showed a characteristic visible absorbance band with a lambda(max) at 443 nm, suggesting that alpha-picolinic acid chelate of Fe2+ ion forms in the solution. Similar characteristic visible absorbance band was also observed for the mixture of Fe2+ ion with quinolinic acid (or fusaric acid, or 2,6-pyridinedicarboxylic acid). The chelation seems to be related to the enhancement by quinolinic acid, alpha-picolinic acid, fusaric acid, and 2,6-pyridinedicarboxylic acid of the Fenton reaction. alpha-Picolinic acid was reported to be a toxic substance isolated from the culture liquids of blast mould (Piricularia oryzae CAVARA). On the other hand, it has also been known that chlorogenic acid protects rice plants from the blast disease. The chlorogenic acid inhibited the formation of the hydroxyl radical in the reaction mixture of alpha-picolinic acid, FeSO4(NH4)2SO4, and H2O2. Thus the inhibition may be a possible mechanism of the protective action of the chlorogenic acid against the blast disease.     

Metabolism of sinapic acid and related compounds in the rat

1. Administration of sinapic acid to the rat results in the excretion of 3-hydroxy-5-methoxyphenylpropionic acid, dihydrosinapic acid, 3-hydroxy-5-methoxycinnamic acid and unchanged sinapic acid in the urine. The sinapic acid conjugate sinalbin is also catabolized to free sinapic acid and 3-hydroxy-5-methoxyphenylpropionic acid in the rat. 2. 3,4,5-Trimethoxycinnamic acid is metabolized in part to sinapic acid and 3-hydroxy-5-methoxyphenylpropionic acid. 3. 3,5-Dimethoxycinnamic acid is metabolized to 3-hydroxy-5-methoxycinnamic acid and 3-hydroxy-5-methoxyphenylpropionic acid. 4. The metabolic interrelationships of these compounds were studied by the administration of intermediates and a metabolic pathway is proposed. 5. The metabolism of the corresponding benzoic acids was studied, but these compounds and their metabolites were shown not to be intermediates or products of the metabolism of the related cinnamic acids.     

An isoelectric focusing study of acid phosphohydrolases in rat liver lysosomes.

The differentiation of rat liver lysosomal acid phosphatase, acid ATPase, acid phosphodiesterase, acid ribonuclease, and acid deoxyribonuclease was studied by isoelectric focusing. To prevent autolytic digestion, inhibitors of cathepsins and neuraminidase were used. The proportion of acidic forms of acid phosphatase, acid ATPase and acid phosphodiesterase was increased by the use of extraction medium containing 0.05% Triton X-100. To investigate the identity of acid ATPase and acid phosphodiesterase, the relative activities among the multiple forms of these enzymes, the acid phosphodiesterase/acid ATPase ratio at each activity peak, and the degree of enzyme inhibition by p-chloromercuriphenyl sulfonic acid were estimated. The results suggest that acid ATPase is not identical with acid phosphodiesterase. With extraction medium free of Triton X-100, acid ribonuclease appeared in two forms. However, in addition to these forms, a new form of this enzyme with a more acidic pI (4.22) emerged when extraction medium containing 0.05% Triton X-100 was used. The major peak of acid deoxyribonuclease with pI=8.40-9.39 was obtained regardless of the extracting method.     

Urinary excretion of dicarboxylic acids from patients with the Zellweger syndrome. Importance of peroxisomes in beta-oxidation of dicarboxylic acids

The urinary excretion of adipic acid, suberic acid and sebacic acid from two patients with the cerebrohepato-renal syndrome of Zellweger was studied. The patients had a complete lack of peroxisomes in the liver as judged by electron microscopy. In the non-ketotic state, the total excretion of free and conjugated adipic acid, suberic acid and sebacic acid was increased by about 100%, 200% and 350%, respectively, as compared to the corresponding excretion from six healthy infants of the same age. The excretion of free dicarboxylic acid was increased to a considerably lesser extent than the free + conjugated dicarboxylic acid. In view of the presence of adipic acid in urine of the Zellweger patients, it is concluded that peroxisomes are not obligatory for beta-oxidation of medium-chain dicarboxylic acids in vivo. The relative accumulation of suberic acid and sebacic acid as compared to adipic acid is, however, consistent with a relative block in the conversion of suberic acid and sebacic acid into adipic acid in patients with the Zellweger syndrome.     

Peroxisome proliferators enhance linoleic acid metabolism in rat liver. Increased biosynthesis of omega 6 polyunsaturated fatty acids

The alterations by peroxisome proliferators of metabolism of linoleic acid in rat liver were studied. Administration of P-chlorophenoxyisobutyric acid (clofibric acid) enhanced in vivo conversion of linoleic acid to its desaturated and/or elongated metabolites, 6,9,12-octadecatrienoic acid, 8,11,14-eicosatrienoic acid, and arachidonic acid, whereas the formation of 11,14-eicosadienoic acid was decreased. These changes observed in vivo were confirmed in vitro to be due to the increases in activities of delta 6 desaturation of linoleic acid to 6,9,12-octadecatrienoic acid (18.4 times), delta 8 desaturation of 11,14-eicosadienoic acid to 8,11,14-eicosatrienoic acid (3.4 times), and delta 5 desaturation of 8,11,14-eicosatrienoic acid to arachidonic acid (4.1 times). No considerable changes in activities of chain elongation of either linoleic acid or 6,9,12-octadecatrienoic acid were observed. The increases in the activities of three desaturations by clofibric acid were prevented by the treatment of rats with cycloheximide. The inductions of delta 6 and delta 5 desaturations were brought about by the treatment of rats with 2,2'-(decamethylenedithio)diethanol or di-(2-ethylhexyl)-phthalate, peroxisome proliferators structurally unrelated to clofibric acid, as well. These changes in metabolism of linoleic acid by clofibric acid were consistent with the changes in mass proportion of omega 6 fatty acids in hepatic lipid. Physiological significance of the marked changes in linoleic acid metabolism by peroxisome proliferators was discussed.     

Characterization of liver cholic acid coenzyme A ligase activity. Evidence that separate microsomal enzymes are responsible for cholic acid and fatty acid activation.

Investigations on the cholic acid CoA ligase activity of rat liver microsomes were made possible by the development of a rapid, sensitive radiochemical assay based on the conversion of [3H]choloyl-CoA. More than 70% of the rat liver cholic acid CoA ligase activity was associated with the microsomal subcellular fraction. The dependencies of cholic acid CoA ligase activity on pH, ATP, CoA, Triton WR-1339, acetone, ethanol, magnesium, and salts were investigated. The hypothesis that the long chain fatty acid CoA ligase activity and the cholic acid CoA ligase activity are catalyzed by a single microsomal enzyme was investigated. The ATP, CoA, and cholic (palmitic) acid kinetics neither supported nor negated the hypothesis. Cholic acid was not an inhibitor of the fatty acid CoA ligase and palmitic acid was not a competitive inhibitor of the cholic acid CoA ligase. The cholic acid CoA ligase activity utilized dATP as a substrate more effectively than did the fatty acid CoA ligase activity. The cholic acid and fatty acid CoA ligase activities appeared to have different pH dependencies, differed in thermolability at 41 degrees, and were differentially inactivated by phospholipase C. Moreover, fatty acid CoA ligase activity was present in microsomal fractions from all rat organs tested while cholic acid CoA ligase activity was detected only in liver microsomes. The data suggest that separate microsomal enzymes are responsible for the cholic acid and the fatty acid CoA ligase activities in liver.     

Formation of ursodeoxycholic acid from chenodeoxycholic acid in the human colon: studies of the role of 7-ketolithocholic acid as an intermediate

The formation of ursodeoxycholic acid from chenodeoxycholic acid and the role of 7-ketolithocholic acid as an intermediate in this biotransformation were studied in vitro in fecal incubations as well as in vivo in the human colon. [24-14C]-Labeled 7-ketolithocholic and chenodeoxycholic acids were studied at various concentrations, and the biotransformation products were analyzed by thin-layer chromatography, gas-liquid chromatography, and mass spectrometry. There was rapid colonic conversion of 7-ketolithocholic acid to ursodeoxycholic acid and, to a lesser extent, to chenodeoxycholic acid. The reduction of 7-ketolithocholic to ursodeoxycholic acid proceeded significantly faster anaerobically and at acid pH than under aerobic and alkaline conditions. When chenodeoxycholic acid was incubated in vitro or instilled into the colon, various amounts of 7-ketolithocholic and ursodeoxycholic acids were formed. The formation of 7-ketolithocholic acid was favored by alkaline conditions. Isotope dilution studies, in which trace amounts of labeled 7-ketolithocholic acid were incubated with unlabeled chenodeoxycholic acid, indicate 7-ketolithocholic acid to be the major intermediate in the intestinal bacterial conversion of chenodeoxycholic to ursodeoxycholic acid.     

华南主要野生蔬菜的脂肪酸成分分析

本实验以华南主要野生蔬菜守宫木、土人参、一点红、白仔菜、紫背菜、鳄嘴花、藤三七、塘葛菜为材料,并以华南特产蔬菜菜心为对照,对8种野生蔬菜的脂肪酸成分进行了分析.结果表明:8种野菜共检出十四酸、软脂酸、棕榈油酸、硬脂酸、油酸、亚油酸、亚麻酸、二十二酸和二十四酸共9种脂肪酸,但不同野菜之间的脂肪酸组成与含量差异极大.8种野菜的饱和脂肪酸的总量都高于菜心,饱和脂肪酸种类最多的是藤三七,含4种.不饱和脂肪酸的变化与饱和脂肪酸相反,8种野菜都低于菜心,但其油酸、亚油酸远高过菜心.菜心富含亚麻酸,但不含亚油酸.可见8种野菜油营养价值较高.     

Identification of short side chain bile acids in urine of patients with cerebrotendinous xanthomatosis

Urine from patients with cerebrotendinous xanthomatosis (CTX) was found to contain a number of minor bile acids along with three major bile acids, 7-epicholic acid, norcholic acid, and cholic acid. The following minor bile acids were identified by combined gas-liquid chromatography-mass spectrometry: 7-ketobisnordeoxycholic acid; 12-ketobisnorchenodeoxycholic acid; 7-ketonordeoxycholic acid; 12-ketochenodeoxycholic acid; 7-ketodeoxycholic acid; 12-ketochendeoxycholic acid; bisnorcholic acid; allonorcholic acid; allocholic acid; 1 beta-hydroxybisnorcholic acid; 1 beta-hydroxynorcholic acid; 1 beta-hydroxycholic acid; 2 beta-hydroxybisnorcholic acid; 2 beta-hydroxy-norcholic acid; 2 beta-hydroxycholic acid. The presence of C22 and C23 bile acids in urine of the CTX patients suggests that bile alcohols having a hydroxyl group at C22 or C23 in the side chain may be further degraded to these bile acids.     

Photoisomerization of retinoic acid and its influence on regulation of human keratinocyte growth and differentiation

Retinoic acid constantly undergoes structural inter-conversions among the geometrical isomers (all-trans-retinoic acid, 9-cis-retinoic acid, 11-cis-retinoic acid, 13-cis-retinoic acid and 9-13-di-cis-retinoic acid) by photoisomerization under natural light. Geometric isomers of retinoic acid thus formed showed different effects on human epidermal keratinocyte growth and differentiation. The ability of the isomers to inhibit the synthesis of cornified envelope (terminal event in the keratinocyte differentiation program) changed rapidly when illuminated by white fluorescent light. The 11-cis-retinoic acid had a 3-fold stronger activity to inhibit the growth of keratinocytes than the other geometric isomers. On the other hand, all-trans-retinoic acid, 9-cis-retinoic acid and 9-13-di-cis-retinoic acid exhibited a 3-fold greater ability to inhibit synthesis of involucrin, transglutaminase and the cornified envelopes. The regulation of keratin expression by the geometric isomers of retinoic acids was extremely complex. Level of keratin-1 (K1) mRNA was increased by 11-cis-retinoic acid and 13-cis-retinoic acid, but suppressed by 9,13-di-cis-retinoic acids while all-trans-retinoic acid and 9-cis-retinoic acid had no effect. Level of keratin-10 (K10) mRNA was strongly inhibited by all-trans-retinoic acid, 9-cis-retinoic acid and 11-cis-retinoic acid as compared to 13-cis-retinoic acid and 9,13-di-cis-retinoic acids. The mRNA level of keratin-14 (K14) was suppressed by all-trans-retinoic acid, 9-cis-retinoic acid and 11-cis-retinoic acid but not influenced by 13-cis-retinoic acid and 9,13-di-cis-retinoic acid. Natural light induced structural inter-conversions among the geometric isomers of retinoic acids in tissues-especially the skin, might play a crucial role in the regulation of growth and differentiation of keratinocytes.     

Effect in the cow of intraruminal infusions of volatile fatty acids and of lactic acid on the secretion of the component fatty acids of the milk fat and on the composition of blood

1. The effects in the cow of intraruminal infusions of acetic acid, propionic acid or butyric acid on the secretion of the component fatty acids of the milk fat, and of these acids and of lactic acid on the composition of the blood plasma of the jugular vein, have been studied. 2. The infusion of acetic acid or butyric acid increased the yield of the C₄–C₁₆ acids of milk fat but decreased the yield of C₁₈ acids. The infusion of propionic acid decreased the yields of all major component acids except palmitic acid and possibly lauric acid. 3. The changes in the concentrations in blood plasma of glucose and of ketone bodies were consistent with the glucogenic effect of propionic acid and the ketogenic effects of butyric acid and acetic acid. The effects of lactic acid were not consistent from cow to cow. Only with the infusion of acetic acid was a significant increase in the concentration of total volatile fatty acids in blood plasma found. Infusions of butyric acid and of propionic acid tended to depress the concentration of citric acid in the blood plasma and infusion of acetic acid increased it. No consistent effects of the infused acids on the concentration in blood plasma of esterified cholesterol, free cholesterol, triglyceride or phospholipid were observed. 4. The possibility is discussed that the effects of the infused acids on milk-fat secretion are caused through an alteration of the concentrations of precursors of milk fat in mammary arterial blood.     

Effect of exogenous ascorbic acid intake on biosynthesis of ascorbic acid in mice

The effect of exogenous ascorbic acid intake on biosynthesis of ascorbic acid in mice has been studied. After the mice were on diets containing added ascorbic acid for two months, the activities of ascorbic acid synthesizing enzymes in the mouse liver homogenates were measured using L-gulono-gamma-lactone as a substrate. Exogenous ascorbic acid intake (0.5, 1 or 5% in the diet) was able to increase the concentration of ascorbic acid in the blood and to decrease the activities of ascorbic acid synthesizing enzymes in mouse liver. The results suggest that ascorbic acid synthesis was controlled by local regulatory mechanism or by the concentration of ascorbic acid in the hepatic portal blood. Ingestion of dietary erythorbic acid, a stereoisomer of ascorbic acid, had no effect on the activities of ascorbic acid synthesizing enzymes.