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1.
The toxicity of four volatile fatty acids (VFAs) as anaerobic digestion (AD) intermediates was investigated at pH 7. Photobacterium phosphoreum T3 was used as an indicator organism. Binary, ternary and mixtures of AD intermediates were designated by letters A (acetic acid + propionic acid), B (acetic acid + butyric acid), C (acetic acid + ethanol), D (propionic acid + butyric acid), E (propionic acid + ethanol), F (butyric acid + ethanol), G (acetic acid + propionic acid + butyric acid), H (acetic acid + propionic acid + ethanol), I (acetic acid + butyric acid+ ethanol), J (propionic acid + butyric acid + ethanol) and K (acetic acid + propionic acid + butyric acid + ethanol) to assess the toxicity through equitoxic mixing ratio method. The IC50 values of acetic acid, propionic acid, butyric acid and ethanol were 9.812, 7.76, 6.717 and 17.33 g/L respectively, displaying toxicity order of: butyric acid > propionic acid > acetic acid > ethanol being additive in nature. The toxic effects of four VFAs could be designated as synergistic and one additive in nature.  相似文献   

2.
酚酸类物质的抑草效应分析   总被引:14,自引:2,他引:12  
运用正交旋转回归试验设计分析5种常见的化感物质替代物水饧酸、对羟基苯甲酸、肉桂酸、香草酸和阿魏酸对田间伴生杂草稗草的抑制效应.结果表明,肉桂酸对稗草根长抑制率的影响最显著。其关系函数的二次项系数为-6.18,达极显著水平,水杨酸、对羟基苯甲酸和阿魏酸对稗草根长的抑制效应趋势与肉桂酸相同,效应曲线均为“n”形抛物线;而香草酸的效应曲线则为“U”形抛物线.当水饧酸、对羟基苯甲酸、肉桂酸、香草酸和阿魏酸浓度水平分别为0.06、0.60、0.24、0.02和0.02mmol·L^-1时,混合物对稗草根长的抑制率最大,达到78.65%。  相似文献   

3.
采用气质联用技术对宽叶独行菜中脂肪酸成分进行了分析,从其乙醇提取物的石油醚萃取部分共分离得到20个组分,采用面积归一化法测定了各组分的含量,其中棕榈酸(hexadecanoic acid)53.980%,硬脂酸(oc-tadecanoic acid)17.063%,二十二烷酸(docosanoic acid)4.769%,二十四烷酸(tetracosanoic acid)3.363%,二十八烷酸(octacosanoic acid)2.773%,花生酸(eicosanoic acid)2.719%,十五烷酸(pentadecanoic acid)2.476%,十七烷酸(heptadecanoic acid)2.291%。此外,三十烷酸(triacontanoic acid,十四烷酸(tetradecanoic acid),二十三烷酸(tricosanoic acid)和二十六烷酸(hexacosanoic acid)的含量均已超过了1%。  相似文献   

4.
Patients suffering from cerebrotendinous xanthomatosis, an inborn error of metabolism in bile acid synthesis, excrete excessive amounts of 23-hydroxylated bile alcohols, 23-norcholic acid and 23-hydroxycholic acid into urine. In this study the configuration of this excreted 23-hydroxycholic acid was established as (23R)-hydroxycholic acid. Urine samples of two treated patients, receiving chenodeoxycholic acid, were investigated to see whether this administered bile acid was partly converted into 23-hydroxychenodeoxycholic acid. One patient was treated with ursodeoxycholic acid for 1 month and subsequently with chenodeoxycholic acid, and the urinary excretion of both (23R)-hydroxychenodeoxycholic acid and (23R)-hydroxyursodeoxycholic acid were followed. Indeed, all three patients excreted (23R)-hydroxylated chenodeoxycholic acid during oral treatment with chenodeoxycholic acid, and the patient treated with ursodeoxycholic acid excreted (23R)-hydroxylated ursodeoxycholic acid. During treatment with chenodeoxycholic acid the excretion of (23R)-hydroxychenodeoxycholic acid increases at first and later on decreases markedly. These findings suggest increased (23R)-hydroxylase activity in patients suffering from cerebrotendinous xanthomatosis, acting both on endogenously synthesized bile alcohols and on exogenously administered bile acids; during continuation of chenodeoxycholic acid treatment in an effective dose (750 mg/day) this enzyme activity gradually disappears.  相似文献   

5.
12-Lipoxygenase and cyclooxygenase 1 are the dominating enzymes that metabolize arachidonic acid in human platelets. In addition to the conversion of arachidonic acid to 12(S)-hydroxyeicosatetraenoic acid, 12-lipoxygenase can also utilize 5(S)-hydroxyeicosatetraenoic acid and 15(S)-hydroxyeicosatetraenoic acid to form 5(S), 12(S)-dihydroxyeicosatetraenoic acid and 14(R), 15(S)-dihydroxyeicosatetraenoic acid, respectively. Furthermore, 15(S)-hydroxyeicosatetraenoic acid works as an inhibitor for 12-lipoxygenase. In the present paper we have studied the influence of albumin on the in vitro metabolism of 5 - and 15 -hydroxyeicosatetraenoic acids, and 5,15 -dihydroxyeicosatetraenoic acid by the platelet 12-lipoxygenase. The presence of albumin reduced the formation of 5(S),12(S)- dihydroxyeicosatetraenoic acid from 5(S)-hydroxyeicosatetraenoic acid, however, it had no effect on the 12(S)-hydroxyeicosatetraenoic acid production from endogenous arachidonic acid. In contrast, when 15(S)-hydroxyeicosatetraenoic acid was incubated with activated platelets, the formation of 14(R), 15(S)- dihydroxyeicosatetraenoic acid was stimulated by the presence of albumin. Furthermore, albumin reduced the inhibitory action 15(S)-hydroxyeicosatetraenoic acid had on 12(S)-hydroxyeicosatetraenoic acid formation from endogenous arachidonic acid. However, addition of exogenous arachidonic acid (20 microm) to the incubations inverted the effects of albumin on the conversion of 15(S)-hydroxyeicosatetraenoic acid to 14(R),15(S)- dihydroxyeicosatetraenoic acid and the production of 12(S)-hydroxyeicosatetraenoic acid in these incubations. Based on the Scatchard equation, the estimates of the binding constants to albumin were 1.8 x 10(5) for 15 -HETE, 1.4 x 10(5) for 12-HETE, and 0.9 x 10(5) for 5 -HETE respectively. These results suggest an important role of albumin for the regulation of the availability of substrates for platelet 12-lipoxygenase.  相似文献   

6.
We investigated the effects of stearic acid (saturated), oleic acid (monounsaturated), linoleic acid (n-6 polyunsaturated), and alpha-linolenic acid (n-3 polyunsaturated) on lipid metabolism in a hepatocyte-derived cell line, HepG2. HepG2 cells were cultured in medium supplemented with either stearic acid (0.1% w/v), oleic acid (0.1% v/v), linoleic acid (0.1% v/v), or alpha-linolenic acid (0.1% v/v). After 24 h, expression of lipid metabolism-associated genes was evaluated by real-time PCR. Alpha-linolenic acid showed a suppressive effect on the hepatic fatty acid de novo synthesis and fatty acid oxidation pathways, while linoleic acid also showed a tendency to suppress these pathways although the effect was weaker. Moreover, alpha-linolenic acid enhanced the expression of enzymes associated with reactive oxygen species (ROS) elimination. In contrast, oleic acid tended to promote fatty acid synthesis and oxidation. In conclusion, alpha-linolenic acid and linoleic acid may be expected to ameliorate hepatic steatosis by downregulating fatty acid de novo synthesis and fatty acid oxidation, and by upregulating ROS elimination enzymes. Oleic acid had no distinct effects for improving steatosis or oxidative stress.  相似文献   

7.
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.  相似文献   

8.
Aconitaseless glutamic acid auxotroph MO-1-9B of Saccharomyces grew in glutamic acid-supplemented minimal medium, but failed to grow when glutamic acid was substituted by proline, arginine, ornithine, or glutamine. This mutant was also unable to utilize lactate or glycerol as a carbon source. Under a glutamic acid-limiting condition, by using acetate-1-(14)C as tracer, the mutant accumulated rather large amounts of (14)C-citric acid and (14)C-succinic acid when compared with the wild-type strain. Under excess glutamic acid supplementation, accumulation of citric acid and succinic acid was considerably reduced. When (14)C-glutamic acid-(U) was used as tracer, (14)C-alpha-ketoglutaric acid, (14)C-citric acid, and (14)C-succinic acid were accumulated in the mutant. The citric acid peak was the largest, followed by alpha-ketoglutaric acid and succinic acid. In the wild-type strain under similar conditions, only small amounts of (14)C-citric acid and (14)C-succinic acid and no (14)C-alpha-ketoglutaric acid were accumulated.  相似文献   

9.
Biotransformations of 3-fluorophthalic acid have been investigated using blocked mutants of Pseudomonas testosteroni that are defective in the metabolism of phthalic acid (benzene-1,2-dicar-boxyfic acid). Mutant strains were grown with L-glutamic acid in the presence of 3-fluorophthalic acid as inducer of phthalic acid catabolic enzymes. Products that accumulated in the medium were isolated, purified and identified as the fluoroanalogues of those produced from phthalic acid by the same strains. The previously undescribed fluorochemicals cis-3-fluoro-4,5-dihydro-4,5-dihydroxyphthalic acid (VI) and 3-fluoro-4,5-dihydroxyphthalic acid (VII) have been obtained by biotransformation of 3-fluorophthalic acid, and 3-fluoro-5-hydroxyphthalic acid (X) from (VI) by freeze drying. In addition, samples of 2-fluoro-3,4-dihydroxybenzoic acid (2-fluoroprotocatechuic acid, VIII) and 3-fluoro-4,Sdi-hydroxybenzoic acid (5-fluoroprotocatechuic acid, IX) were obtained with a mutant deficient in the ring-fission enzyme, showing that the fluorine substituent in their precursor substrate (VII) is not recognized by the decarboxylase of the pathway, which shows no preference for which carboxyl group is removed. These studies of 3-fluorophthalic acid catabolism demonstrate the opportunities available for the production of novel fluorochemicals in reasonable yields by microbial transformations.  相似文献   

10.
Caffeic acid and 5-caffeoylquinic acid are naturally occurring phenolic acid and its quinic acid ester found in plants. In this article, potential effects of 5-caffeoylquinic acid and caffeic acid on P-selectin expression were investigated due to its significant involvement in platelet activation. First, the effects of 5-caffeoylquinic acid and caffeic acid on cyclooxygenase (COX) enzymes were determined due to their profound involvement in regulating P-selectin expression on platelets. At the concentration of 0.05 microM, 5-caffeoylquinic acid and caffeic acid were both able to inhibit COX-I enzyme activity by 60% (P<.013) and 57% (P<.017), respectively. At the same concentration, 5-caffeoylquinic acid and caffeic acid were also able to inhibit COX-II enzyme activity by 59% (P<.012) and 56% (P<.015), respectively. As expected, 5-caffeoylquinic acid and caffeic acid were correspondingly able to inhibit P-selectin expression on the platelets by 33% (P<.011) and 35% (P<.018), at the concentration of 0.05 microM. In animal studies, 5-caffeoylquinic acid and caffeic acid orally administered to mice were detected as intact forms in the plasma. Also, P-selectin expression was respectively reduced by 21% (P<.016) and 44% (P<.019) in the plasma samples from mice orally administered 5-caffeoylquinic acid (400 microg per 30 g body weight) and caffeic acid (50 microg per 30 g body weight). These data suggest that both 5-caffeoylquinic acid and caffeic acid orally administered can be absorbed and suppress P-selectin expression on mouse platelets.  相似文献   

11.
Microbial production of chemicals and materials from renewable carbon sources is becoming increasingly important to help establish sustainable chemical industry. In this paper, we review current status of metabolic engineering for the bio-based production of linear and saturated dicarboxylic acids and diamines, important platform chemicals used in various industrial applications, especially as monomers for polymer synthesis. Strategies for the bio-based production of various dicarboxylic acids having different carbon numbers including malonic acid (C3), succinic acid (C4), glutaric acid (C5), adipic acid (C6), pimelic acid (C7), suberic acid (C8), azelaic acid (C9), sebacic acid (C10), undecanedioic acid (C11), dodecanedioic acid (C12), brassylic acid (C13), tetradecanedioic acid (C14), and pentadecanedioic acid (C15) are reviewed. Also, strategies for the bio-based production of diamines of different carbon numbers including 1,3-diaminopropane (C3), putrescine (1,4-diaminobutane; C4), cadaverine (1,5-diaminopentane; C5), 1,6-diaminohexane (C6), 1,8-diaminoctane (C8), 1,10-diaminodecane (C10), 1,12-diaminododecane (C12), and 1,14-diaminotetradecane (C14) are revisited. Finally, future challenges are discussed towards more efficient production and commercialization of bio-based dicarboxylic acids and diamines.  相似文献   

12.
The complex pharmacological profile (excitation/inhibition) of ibotenic acid on single neurons in the mammalian CNS prompted studies on the stability of ibotenic acid and a number of structurally related excitatory amino acids under different in vitro conditions in the presence or absence of enzymes. Ibotenic acid, (RS)-3-hydroxy-4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridine-7-carboxylic acid (7-HPCA), (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), and (RS)-alpha-amino-3-hydroxy-4-bromo-5-isoxazolepropionic acid (4-Br-homoibotenic acid) were all inhibitors of (S)-glutamic acid decarboxylase (GAD) in mouse brain homogenates, but only ibotenic acid was shown to undergo decarboxylation during incubation with brain homogenates. The formation of the decarboxylated product, muscimol, which primarily occurred in a synaptosomal fraction, was dependent on the presence of pyridoxal-5-phosphate (PALP) and was inhibited by (S)-glutamic acid, 3-mercaptopropionic acid (3MPA), aminooxyacetic acid (AOAA), and allyglycine, suggesting that ibotenic acid is a substrate for GAD. The overall decomposition rate for ibotenic acid (8.7 nmol min-1 mg-1 of protein), which apparently embraces other reactions in addition to decarboxylation to muscimol, was higher than the rate of decarboxylation of (S)-glutamic acid (3.2 nmol min-1 mg-1 of protein). At pH 7.4 and 37 degrees C, but in the absence of enzymes, none of the excitatory amino acids under study underwent any detectable decomposition, whereas ibotenic acid and 7-HPCA, but not AMPA and 4-Br-homoibotenic acid, decomposed, partially by decarboxylation, at 100 degrees C in a pH-dependent manner. In the presence of liver homogenates, ibotenic acid was also shown to decompose.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
The effect of a koji (Aspergillus awamori mut.) extract on the caffeoylquinic acid derivatives purified from sweetpotato (Ipomoea batatas L.) leaves was examined to develop the mass production of caffeic acid. A koji extract hydrolyzed the caffeoylquinic acid derivatives, chlorogenic acid, 3,4-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, 4,5-di-O-caffeoylquinic acid and 3,4,5-tri-O-caffeoylquinic acid, to caffeic acid. Furthermore, the koji extract also converted the major polyphenolic components from sweetpotato, burdock (Arctium lappa L.), and mugwort (Artemisia indica var. maximowiczii) leaves to caffeic acid. These results suggest that the production of caffeic acid from plant resources containing caffeoylquinic acid derivatives is possible.  相似文献   

14.
发酵无花果香料的挥发性成分分析   总被引:6,自引:0,他引:6  
利用微生物发酵无花果开发特色香料,并采用同时蒸馏萃取装置收集挥发性成分并用气相色谱一质谱仪对生物技术制备的无花果香料挥发性成分进行分离和鉴定,经毛细管色谱分离出47种组分,确认了其中的45种成分,并用面积归一化法测定了各种成分的百分含量,其主要成分为:9,12-十八碳二烯酸乙酯(27.34%)、十六酸乙酯(23.99%)、邻苯二甲酸二丁酯(6.18%)、邻苯二甲酸二异丁酯(5.52%)、9,12-十八碳二烯酸甲酯(4.72%)、十六酸甲酯(4.67%)、9,12,15-十八碳三烯酸乙酯(4.48%)、9-十八碳烯酸乙酯(3.80%)、糠醛(2.53%)、9,12,15-十八碳三烯酸甲酯(1.85%)、十八酸乙酯(1.42%)、9-十八碳烯酸甲酯(1.26%)等。  相似文献   

15.
在温室沙培灭菌条件下,以Al-P为磷源、枳为试材、Glomus mosseae (G.m)和G.versiforme (G.v)为菌剂,研究低磷胁迫下AM真菌对枳实生苗干物重、吸磷效应及根系分泌有机酸的影响。结果表明,接种AM真菌显著增加枳地上部、地下部干物重,增幅16.79%~135.25%;同时显著增加其吸磷量,菌丝对植株的吸磷贡献率为17.04%~71.95%(G.m>G.v),施Al-P显著提高菌丝吸磷贡献率。接种AM真菌的根系分泌的有机酸种类与对照有所不同,未接种处理枳分泌的有机酸有草酸、苹果酸、乳酸、乙酸、顺丁烯二酸和柠檬酸等6种,而接种G.m的则检测到草酸、酒石酸、苹果酸、乳酸、乙酸、柠檬酸、丁二酸等7种,G.v处理的检测到酒石酸,接种处理均未检测到顺丁烯二酸;接种丛枝菌根真菌增加了枳根系分泌有机酸的量(比未接种处理增加19.80~56.87 mg/kg,且施用AlPO4后有机酸含量显著增加(增加20.06~21.84 mg/kg);未接种植株根系仅分泌少量有机酸;接种植株根系分泌的有机酸以苹果酸(42.87%)、柠檬酸(39.22%)和草酸(12.06%)为主。  相似文献   

16.
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.  相似文献   

17.
喜光花叶的化学成分研究(Ⅲ)   总被引:1,自引:0,他引:1  
从喜光花Actephila merrilliana叶中分离得到11个化合物,通过理化方法和波谱数据分别鉴定为5,5’-dimethoxy-alloagerasasin(1)、对羟基苯甲醛(2)、丁香酸(3)、正十八烷酸(4)、反式桂皮酸(5)、对甲氧基苯甲酸(6)、间苯二酚(7)、邻苯二甲酸(8)、邻羟基苯甲酸(9)、对羟基苯甲酸(10)以及戊二酸(11),以上所有化合物均首次从该属植物中分离得到。  相似文献   

18.
The triacylglycerol synthesis from exogenous linoleic acid (18:2(n-6], linolenic acid (18:3(n-3], dihomogammalinolenic acid (20:3(n-6], eicosapentaenoic acid (20:5(n-3] and oleic acid (18:1(n-9] was observed to be significantly increased in isolated liver cells from female rats compared with males. The rate of fatty acid oxidation and phospholipid biosynthesis was concomitantly more important in male cells. With the C22-polyenoic fatty acids, adrenic acid (22:4(n-6] and docosahexaenoic acid (22:6(n-3), only a minor sex-related difference in fatty acid metabolism was found.  相似文献   

19.
绿僵菌SC0924酚酸类代谢产物及其抗荔枝霜疫霉活性   总被引:1,自引:0,他引:1  
从绿僵菌SC0924固体发酵物中分离得到8个酚酸类化合物,通过波谱分析,分别鉴定为香草酸(1)、丁香酸(2)、邻氨基苯甲酸(3)、苯乙酸(4)、阿魏酸(5)、二氢阿魏酸(6)、2-羟基-3-苯丙酸(7)和2-羟基-3-对羟基苯丙酸丁酯(8).以滤纸片琼脂扩散法对以上化合物进行抗荔枝霜疫霉活性试验,结果表明除化合物2和6外,其余化合物均有抑菌活性.  相似文献   

20.
The caffeoylquinic acid derivatives, 3-mono-O-caffeoylquinic acid (chlorogenic acid, ChA), 3,4-di-O-caffeoylquinic acid (3,4-diCQA), 3,5-di-O-caffeoylquinic acid (3,5-diCQA), 4,5-di-O-caffeoylquinic acid (4,5-diCQA) and 3,4,5-tri-O-caffeoylquinic acid (3,4,5-triCQA), and caffeic acid (CA) were isolated from the sweetpotato (Ipomoea batatas L.) leaf. We examined the antimutagenicity of these caffeoylquinic acid compounds to promote new uses of the sweetpotato leaf. These caffeoylquinic acid derivatives effectively inhibited the reverse mutation induced by Trp-P-1 on Salmonella typhimurium TA 98. The antimutagenicity of these derivatives was 3,4,5-triCQA > 3,4-diCQA = 3,5-diCQA = 4,5-diCQA > ChA in this order. There was no difference in the antimutagenicity of all dicaffeoylquinic acid derivatives. A comparison of the activities and structures of these compounds suggested that the number of caffeoyl groups bound to quinic acid played a role in the antimutagenicity of the caffeoylquinic acid derivatives. The sweetpotato leaves contained distinctive polyphenolic components with a high content of mono-, di-, and tricaffeoylquinic acid derivatives and could be a source of physiological functions.  相似文献   

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