Forty-nine microbial strains were used to screen their ability for the microbiological transforma-tion of ginsenoside Rg1. Aspergillus niger (3.1858) and Absidia coerulea (3.3538) were found to convert ginsenoside Rg1...Forty-nine microbial strains were used to screen their ability for the microbiological transforma-tion of ginsenoside Rg1. Aspergillus niger (3.1858) and Absidia coerulea (3.3538) were found to convert ginsenoside Rg1 efficiently to less polar metabolites. Preparative scale transformation with both fungi Absidia coerulea (3.3538) and Aspergillus niger (3.1858) have resulted in the production of one same metabolite (MT1). Its structure was char-acterized as 6-O-b-D-glucopyranosyl-20(S)-protopanaxatriol (Ginsenoside Rh1) on the basis of its TOF-MS and 1H, 13C NMR spectral data. The biotransformation kinetic curves for Ginsenoside Rg1 and MT1 were reported for the first time, and the biotransformation pathway was proposed.展开更多
AIM： To observe the biotransformation process of a Chinese compound, aesculin, by human gut bacteria, and to identify its metabolites in rat urine.METHODS： Representative human gut bacteria were collected from 20 he...AIM： To observe the biotransformation process of a Chinese compound, aesculin, by human gut bacteria, and to identify its metabolites in rat urine.METHODS： Representative human gut bacteria were collected from 20 healthy volunteers, and then utilized in vitro to biotransform aesculin under anaerobic conditions. At 0, 2, 4, 8, 12, 16, 24, 48 and 72 h postincubation, 10 mL of culture medium was collected. Metabolites of aesculin were extracted 3 × from rat urine with methanol and analyzed by HPLC. For in vivo metabolite analysis, aesculetin （100 mg/kg） was administered to rats via stomach gavage, rat urine was collected from 6 to 48 h post-administration, and metabolite analysis was performed by LC/ESI-MS and MS/MS in the positive and negative modes.RESULTS： Human gut bacteria could completely convert aesculin into aesculetin in vitro. The biotransformation process occurred from 8 to 24 h post-incubation, with its highest activity was seen from 8 to 12 h. The in vitro process was much slower than the in vivo process. In contrast to the in vitro model, six aesculetin metabolites were identified in rat urine, including 6-hydroxy-7-glucocoumarin（M1）, 6-hydroxy-7-sulf-coumarin （M2）, 6, 7-digluco-coumarin （M3）, 6-glc-7-gluco-coumarin （M4）, 6-O-methyl-7-gluco-coumarin （MS） and 6-O-methyl-7- sulf-coumarin （M6）. Of which, M2 and M6 were novel metabolites.CONCLUSION： Aesculin can be transferred into aesculetin by human gut bacteria and is further modified by the host in vivo. The diverse metabolites of aesculin may explain its pleiotropic pharmaceutical effects.展开更多
The bioconversion of coal at ambient conditions is a promising technology for coal processing, although the mechanisms of coal degradation are still not understood fully. In this work, the bioconversion of lig- nite w...The bioconversion of coal at ambient conditions is a promising technology for coal processing, although the mechanisms of coal degradation are still not understood fully. In this work, the bioconversion of lig- nite was studied using a fungus isolated from decaying wood. The lignite samples were oxidized with nitric acid under moderate conditions and then the oxidized samples were placed on a potato medium with isolated fungus for lignite bioconversion. Lignite, oxidized lignite and residual products after bioconversion of lignite were sequentially extracted with petroleum ether, CS2, methanol, acetone and tetrahydrofuran （THt：）, and then each extract was characterized by gas chromatography-mass spectrom- etry （GC/MS）. The differences in composition and structure among the samples were inferred by compar- ing the differences between the extracts. The results show that aromatics with one or several benzene rings and their derivatives; and some long-chain alkanes containing oxygen decreased in the metha- nol-, acetone-, and THF-soluble fraction from residual lignite, whereas long chain or a few branched alkanes and small quantities of aromatic compounds increased in petroleum ether and CS2 soluble fractions.展开更多
Animal nutrition is one of the most important limiting factors in animal production, especially in ruminants, providing proteins being the main constraint, due to the limited availability and high cost of protein sour...Animal nutrition is one of the most important limiting factors in animal production, especially in ruminants, providing proteins being the main constraint, due to the limited availability and high cost of protein sources （oilseed meals）. Currently in the dam ＂El lnfiernillo＂ in Michoacan Mexico, has a large population of devil fish （Pterygoplichthys spp.）, which is an economic and ecological problem, because it is not consumed by humans and causes pollution to be discarded directly into the environment. For that reason the objective of this study was to evaluate the use of silage acid devil fish （SADF） in fattening beef cattle as a protein supplement. SADF is defined as a product semi-liquid or pasty mixed with formic acid, which leads to a decrease in pH to near 4.0. Used 18 young bulls （Bos taurus × Bos indicus） for 60 days with a starting weight of 278.9 ± 51.2 kg, housed in individual pens with food and water ad libitum were randomly assigned to three treatments with different levels of inclusion SADF （0%, 12% and 18%）. They were weighed to the beginning of the experiment and later every 30 days, previous fasting of 24 hours. To determine the food consumption, weigh every day the offered food and the surplus. There were no significant differences （P 〈 0.05） among treatments with different levels of inclusion of SADF with respect to daily weight gain, with values of 952 ± 324, 927 ±322 and 854 ± 307 g/day, respectively. The dry matter intake （DMI） was 8.9, 9.3 and 7.7 kg/day to 0%, 12% and 18% of SADF, respectively. In the same values for feed conversion were 9.34, 10.03 and 9.01 kg DMI/kg of weigh live, and carcass yield of 60.6%, 60.3% and 58.5%, respectively. It is concluded that fish silage acid devil is an excellent alternative in feeding beef cattle as a protein supplement.展开更多
文摘Forty-nine microbial strains were used to screen their ability for the microbiological transforma-tion of ginsenoside Rg1. Aspergillus niger (3.1858) and Absidia coerulea (3.3538) were found to convert ginsenoside Rg1 efficiently to less polar metabolites. Preparative scale transformation with both fungi Absidia coerulea (3.3538) and Aspergillus niger (3.1858) have resulted in the production of one same metabolite (MT1). Its structure was char-acterized as 6-O-b-D-glucopyranosyl-20(S)-protopanaxatriol (Ginsenoside Rh1) on the basis of its TOF-MS and 1H, 13C NMR spectral data. The biotransformation kinetic curves for Ginsenoside Rg1 and MT1 were reported for the first time, and the biotransformation pathway was proposed.
基金Supported by Department of Traditional Chinese Medicine,Sichuan Province,No.03JY-002
文摘AIM： To observe the biotransformation process of a Chinese compound, aesculin, by human gut bacteria, and to identify its metabolites in rat urine.METHODS： Representative human gut bacteria were collected from 20 healthy volunteers, and then utilized in vitro to biotransform aesculin under anaerobic conditions. At 0, 2, 4, 8, 12, 16, 24, 48 and 72 h postincubation, 10 mL of culture medium was collected. Metabolites of aesculin were extracted 3 × from rat urine with methanol and analyzed by HPLC. For in vivo metabolite analysis, aesculetin （100 mg/kg） was administered to rats via stomach gavage, rat urine was collected from 6 to 48 h post-administration, and metabolite analysis was performed by LC/ESI-MS and MS/MS in the positive and negative modes.RESULTS： Human gut bacteria could completely convert aesculin into aesculetin in vitro. The biotransformation process occurred from 8 to 24 h post-incubation, with its highest activity was seen from 8 to 12 h. The in vitro process was much slower than the in vivo process. In contrast to the in vitro model, six aesculetin metabolites were identified in rat urine, including 6-hydroxy-7-glucocoumarin（M1）, 6-hydroxy-7-sulf-coumarin （M2）, 6, 7-digluco-coumarin （M3）, 6-glc-7-gluco-coumarin （M4）, 6-O-methyl-7-gluco-coumarin （MS） and 6-O-methyl-7- sulf-coumarin （M6）. Of which, M2 and M6 were novel metabolites.CONCLUSION： Aesculin can be transferred into aesculetin by human gut bacteria and is further modified by the host in vivo. The diverse metabolites of aesculin may explain its pleiotropic pharmaceutical effects.
基金supported by the Fundamental Research Funds for the Central Universities (No. 2010QNB12)the National Natural Science Foundation of China (No. 50921002)
文摘The bioconversion of coal at ambient conditions is a promising technology for coal processing, although the mechanisms of coal degradation are still not understood fully. In this work, the bioconversion of lig- nite was studied using a fungus isolated from decaying wood. The lignite samples were oxidized with nitric acid under moderate conditions and then the oxidized samples were placed on a potato medium with isolated fungus for lignite bioconversion. Lignite, oxidized lignite and residual products after bioconversion of lignite were sequentially extracted with petroleum ether, CS2, methanol, acetone and tetrahydrofuran （THt：）, and then each extract was characterized by gas chromatography-mass spectrom- etry （GC/MS）. The differences in composition and structure among the samples were inferred by compar- ing the differences between the extracts. The results show that aromatics with one or several benzene rings and their derivatives; and some long-chain alkanes containing oxygen decreased in the metha- nol-, acetone-, and THF-soluble fraction from residual lignite, whereas long chain or a few branched alkanes and small quantities of aromatic compounds increased in petroleum ether and CS2 soluble fractions.
文摘Animal nutrition is one of the most important limiting factors in animal production, especially in ruminants, providing proteins being the main constraint, due to the limited availability and high cost of protein sources （oilseed meals）. Currently in the dam ＂El lnfiernillo＂ in Michoacan Mexico, has a large population of devil fish （Pterygoplichthys spp.）, which is an economic and ecological problem, because it is not consumed by humans and causes pollution to be discarded directly into the environment. For that reason the objective of this study was to evaluate the use of silage acid devil fish （SADF） in fattening beef cattle as a protein supplement. SADF is defined as a product semi-liquid or pasty mixed with formic acid, which leads to a decrease in pH to near 4.0. Used 18 young bulls （Bos taurus × Bos indicus） for 60 days with a starting weight of 278.9 ± 51.2 kg, housed in individual pens with food and water ad libitum were randomly assigned to three treatments with different levels of inclusion SADF （0%, 12% and 18%）. They were weighed to the beginning of the experiment and later every 30 days, previous fasting of 24 hours. To determine the food consumption, weigh every day the offered food and the surplus. There were no significant differences （P 〈 0.05） among treatments with different levels of inclusion of SADF with respect to daily weight gain, with values of 952 ± 324, 927 ±322 and 854 ± 307 g/day, respectively. The dry matter intake （DMI） was 8.9, 9.3 and 7.7 kg/day to 0%, 12% and 18% of SADF, respectively. In the same values for feed conversion were 9.34, 10.03 and 9.01 kg DMI/kg of weigh live, and carcass yield of 60.6%, 60.3% and 58.5%, respectively. It is concluded that fish silage acid devil is an excellent alternative in feeding beef cattle as a protein supplement.
