It is now widely recognized that chronic hepatitis C (CHC)is associated with insulin resistance(IR)and type 2 diabetes,so can be considered a metabolic disease.IR is most strongly associated with hepatitis C virus(HCV...It is now widely recognized that chronic hepatitis C (CHC)is associated with insulin resistance(IR)and type 2 diabetes,so can be considered a metabolic disease.IR is most strongly associated with hepatitis C virus(HCV)genotype 1,in contrast to hepatic steatosis, which is associated with genotype 3 infection.Apart from the well-described complications of diabetes,IR in CHC predicts faster progression to fibrosis and cirrhosis that may culminate in liver failure and hepatocellular carcinoma.More recently,it has been recognized that IR in CHC predicts a poor response to antiviral therapy. The molecular mechanisms for the association between IR and HCV infection are not well defined.This review will elaborate on the clinical associations between CHC and IR and summarize current knowledge regarding the molecular mechanisms that potentially mediate HCV-associated IR.展开更多
The secondary metabolites synthesized by plants are economically important chemical compounds in the agricultural and industrial areas such as food, perfumery and pharmaceutical sectors. In recent years, attempts for ...The secondary metabolites synthesized by plants are economically important chemical compounds in the agricultural and industrial areas such as food, perfumery and pharmaceutical sectors. In recent years, attempts for their production by in vitro plant cell and tissue cultures have been accelerated considerably. Colchicine, the principle secondary metabolite of Colchicum autumnale L. and Gloriosa superba L., is an important alkaloid that has poison effect used for treatment of various diseases and plant breeding studies. Presently, colchicine has been produced by using the seeds of C. autumnale L. and the tubers of G. superba L. through different chemical extraction methods. Applying in vitro plant cell and tissue cultures together with metabolic and genetic engineering techniques, large-scale production of colchicine can be achieved from the above two plant species.展开更多
Iron is an essential trace metal in the human diet due to its obligate role in a number of metabolic processes. In the diet, iron is present in a number of different forms, generally described as haem (from haemoglob...Iron is an essential trace metal in the human diet due to its obligate role in a number of metabolic processes. In the diet, iron is present in a number of different forms, generally described as haem (from haemoglobin and myoglobin in animal tissue) and non-haem iron (including ferric oxides and salts, ferritin and lactoferrin). This review describes the molecular mechanisms that co-ordinate the absorption of iron from the diet and its release into the circulation. While many components of the iron transport pathway have been elucidated, a number of key issues still remain to be resolved. Future work in this area will provide a clearer picture regarding the transcellular flux of iron and its regulation by dietary and humoral factors.展开更多
A new method to detect multiple outliers in multivariate data is proposed. It is a combination of minimum subsets, resampling and self-organizing map (SOM) algorithm introduced by Kohonen,which provides a robust way w...A new method to detect multiple outliers in multivariate data is proposed. It is a combination of minimum subsets, resampling and self-organizing map (SOM) algorithm introduced by Kohonen,which provides a robust way with neural network. In this method, the number and organization of the neurons are selected by the characteristics of the spectra, e.g., the spectra data are often changed linearly with the concentration of the components and are often measured repeatedly, etc. So the spatial distribution of the neurons can be arranged by this characteristic. With this method, all the outliers in the spectra can be detected, which cannot be solved by the traditional method, and the speed of computation is higher than that of the traditional neural network method. The results of the simulation and the experiment show that this method is simple, effective, intuitionistic and all the outliers in the spectra can be detected in a short time. It is useful when associated with the regression model in the near infra-red research.展开更多
A chemical investigation of the ethyl acetate extract of the fermentation broth of Alternaria tenuissima EN- 192, an endophytic fungus obtained from the stems of the marine mangrove plant Rhizophora stylosa, resulted ...A chemical investigation of the ethyl acetate extract of the fermentation broth of Alternaria tenuissima EN- 192, an endophytic fungus obtained from the stems of the marine mangrove plant Rhizophora stylosa, resulted in the isolation of nine known secondary metabolites, including four indole-diterpenoids: penijanthine A (1), paspaline (2), paspalinine (3), and penitrem A (4); three tricycloalternarene derivatives: tricycloalternarene 3a (5), tricycloalternarene lb (6), and tricycloalternarene 2b (7); and two alternariol congeners: djalonensone (8) and alternariol (9). The chemical structures of these metabolites were characterized through a combination of detailed spectroscopic analyses and their comparison with reports from the literature. The inhibitory activities of each isolated compound against four bacteria were evaluated and compounds 5 and 8 displayed moderate activity against the aquaculture pathogenic bacterium Vibrio anguillarum, with inhibition zone diameters of 8 and 9 mm, respectively, at 100 gg/disk. To the best of our knowledge, this is the first report on the secondary metabolites of mangrove-derived Alternaria tenuissima and also the first report of the isolation ofindole-diterpenoids from fungal genus Alternaria.展开更多
The effect of some phenolic compounds recurrent in wines on technological features of Oenococcus oeni was studied in order to individuate those strains to be utilized as starter in the deacidification of aged red wine...The effect of some phenolic compounds recurrent in wines on technological features of Oenococcus oeni was studied in order to individuate those strains to be utilized as starter in the deacidification of aged red wines. For this purpose, the growth and the L-malic acid metabolism of 100O. oeni strains, previously isolated from different wines, was assayed in a synthetic medium added with ethanol, malic acid and phenol carboxylic (gallic, caffeic, p-coumaric and ferulic) acids or flavonoids (catechin and quercetin) at different concentrations. Results evidenced a different sensitivity of strains to each assayed compound. All the compounds restrained or stimulated the growth of 57 and 11 strains respectively, while no effect was detected on 6 strains. The remaining 26 strains showed a different behaviour: all were restrained by ferulic acid and stimulated by gallic acid and catechin. As for caffeic acid, 17 out of 26 strains were restrained, while 9 strains were stimulated. The main result obtained in this study was the establishment of a relationship between the effect of phenolic compounds on the O. oeni growth and the behaviour of the malolactic fermentation. This study may enrich the selection criteria of strains for the deacidification of aged red wines.展开更多
Cherry tomatoes (Lycopersicon esculentura Mill., cv. hongyangli) were hydroponically cultivated in a greenhouse to determine the effect of different nitrogen (N) forms on organic acid concentration and the activit...Cherry tomatoes (Lycopersicon esculentura Mill., cv. hongyangli) were hydroponically cultivated in a greenhouse to determine the effect of different nitrogen (N) forms on organic acid concentration and the activities of related enzymes involved in nitrogen and organic acid metabolism during cherry tomato fruit development. The results showed that fruit nitrate reductase (NR) activity was much higher following treatment with 100% NO3 and 75% NO3 + 25% NH+ than with 100% NH+ except at maturity. Glutamine synthetase (GS) activity trended downward during fruit development under all three treatments. Plants fed 100% NH+ had the lowest fruit citrate and malate levels at maturity, with the highest malate concentration at an early stage. The activity of phosphoenolpyruvate carboxylase (PEPC) was found to be in accord with the malate concentration with every N source. Under all three N forms, the citrate synthase (CS) activity peaked one week before the citrate concentration.展开更多
Bacterial prodigiosins are red-colored secondary metabolites with multiple activities,such as anticancer,antimalarial and immunosuppressive,which hold great potential for medical applications.In this study,dramaticall...Bacterial prodigiosins are red-colored secondary metabolites with multiple activities,such as anticancer,antimalarial and immunosuppressive,which hold great potential for medical applications.In this study,dramatically enhanced prodigiosins(RED) production in Streptomyces coelicolor was achieved by combinatorial metabolic engineering,including inactivation of the repressor gene ohkA,deletion of the actinorhodin(ACT) and calcium-dependent antibiotic(CDA) biosynthetic gene clusters(BGCs) and multi-copy chromosomal integration of the RED BGC.The results showed that ohkA deletion led to a 1-fold increase of RED production over the wild-type strain M145.Then,the ACT and CDA BGCs were deleted successively based on the AohkA mutant(SBJ101).To achieve multi-copy RED BGC integration,artificial ΦC31 attB site(s) were inserted simultaneously at the position where the ACT and CDA BGCs were deleted.The resulting strains SBJ102(with a single deletion of the ACT BGC and insertion of one artificial attB site) and SBJ103(with the deletion of both BGCs and insertion of two artificial attB sites) produced 1.9-and 6-fold higher RED titers than M145,respectively.Finally,the entire RED BGC was introduced into mutants from SBJ101 to SBJ103,generating three mutants(from SBJ104 to SBJ106) with chromosomal integration of one to three copies of the RED BGC.The highest RED yield was from SBJ106,which produced a maximum level of 96.8 mg g^(-1) cell dry weight,showing a 12-fold increase relative to M145.Collectively,the metabolic engineering strategies employed in this study are very efficient for the construction of high prodigiosin-producing strains.展开更多
A bacterial strain, Arthrobacter oxydans (B4), capable of degrading benzo[a]pyrene (BaP) in water body, was isolated from a polycyclic aromatic hydrocarbons-contaminated site. Effects of different factors, such as...A bacterial strain, Arthrobacter oxydans (B4), capable of degrading benzo[a]pyrene (BaP) in water body, was isolated from a polycyclic aromatic hydrocarbons-contaminated site. Effects of different factors, such as reaction time, pH value, temperature and organic nutrients, on BaP biodegradation by the strain B4 were studied. After 5 d treatment, the concentration of BaP in mineral salts medium was reduced to 0.318 mg L-1, compared to the initial concentration of 1.000 mg L-1. There was a process of acid formation during the degradation with pH falling from initial 7.01 to 4.61 at 5 d, so keeping the water body under slightly alkaline condition was propitious to BaP degradation. Strain B4 efficiently degraded BaP at 20 to 37 ~C with addition of organic nutrients. The biodegradation and transformation of BaP mainly occurred on cell surfaces, and extracellular secretions played an important role in these processes. Fourier transform infrared spectroscopy and gas chromatograph-mass spectrometer analyses of metabolites showed that ring cleavage occurred in the BaP degradation process and the resulting metabolically utilizable substrates were generated as sole carbon sources for B4 growth. Furthermore, mineralization extent of metabolites was verified by determining the total organic carbon and inorganic carbon in the degradation system.展开更多
基金Supported by Australian National Health and Medical Research Council and the Robert W Storr Bequest to the University of Sydney
文摘It is now widely recognized that chronic hepatitis C (CHC)is associated with insulin resistance(IR)and type 2 diabetes,so can be considered a metabolic disease.IR is most strongly associated with hepatitis C virus(HCV)genotype 1,in contrast to hepatic steatosis, which is associated with genotype 3 infection.Apart from the well-described complications of diabetes,IR in CHC predicts faster progression to fibrosis and cirrhosis that may culminate in liver failure and hepatocellular carcinoma.More recently,it has been recognized that IR in CHC predicts a poor response to antiviral therapy. The molecular mechanisms for the association between IR and HCV infection are not well defined.This review will elaborate on the clinical associations between CHC and IR and summarize current knowledge regarding the molecular mechanisms that potentially mediate HCV-associated IR.
文摘The secondary metabolites synthesized by plants are economically important chemical compounds in the agricultural and industrial areas such as food, perfumery and pharmaceutical sectors. In recent years, attempts for their production by in vitro plant cell and tissue cultures have been accelerated considerably. Colchicine, the principle secondary metabolite of Colchicum autumnale L. and Gloriosa superba L., is an important alkaloid that has poison effect used for treatment of various diseases and plant breeding studies. Presently, colchicine has been produced by using the seeds of C. autumnale L. and the tubers of G. superba L. through different chemical extraction methods. Applying in vitro plant cell and tissue cultures together with metabolic and genetic engineering techniques, large-scale production of colchicine can be achieved from the above two plant species.
文摘Iron is an essential trace metal in the human diet due to its obligate role in a number of metabolic processes. In the diet, iron is present in a number of different forms, generally described as haem (from haemoglobin and myoglobin in animal tissue) and non-haem iron (including ferric oxides and salts, ferritin and lactoferrin). This review describes the molecular mechanisms that co-ordinate the absorption of iron from the diet and its release into the circulation. While many components of the iron transport pathway have been elucidated, a number of key issues still remain to be resolved. Future work in this area will provide a clearer picture regarding the transcellular flux of iron and its regulation by dietary and humoral factors.
文摘A new method to detect multiple outliers in multivariate data is proposed. It is a combination of minimum subsets, resampling and self-organizing map (SOM) algorithm introduced by Kohonen,which provides a robust way with neural network. In this method, the number and organization of the neurons are selected by the characteristics of the spectra, e.g., the spectra data are often changed linearly with the concentration of the components and are often measured repeatedly, etc. So the spatial distribution of the neurons can be arranged by this characteristic. With this method, all the outliers in the spectra can be detected, which cannot be solved by the traditional method, and the speed of computation is higher than that of the traditional neural network method. The results of the simulation and the experiment show that this method is simple, effective, intuitionistic and all the outliers in the spectra can be detected in a short time. It is useful when associated with the regression model in the near infra-red research.
基金Supported by the National Natural Science Foundation of China(Nos.30910103914,31270403)the Ministry of Science and Technology(No.2010CB833802)
文摘A chemical investigation of the ethyl acetate extract of the fermentation broth of Alternaria tenuissima EN- 192, an endophytic fungus obtained from the stems of the marine mangrove plant Rhizophora stylosa, resulted in the isolation of nine known secondary metabolites, including four indole-diterpenoids: penijanthine A (1), paspaline (2), paspalinine (3), and penitrem A (4); three tricycloalternarene derivatives: tricycloalternarene 3a (5), tricycloalternarene lb (6), and tricycloalternarene 2b (7); and two alternariol congeners: djalonensone (8) and alternariol (9). The chemical structures of these metabolites were characterized through a combination of detailed spectroscopic analyses and their comparison with reports from the literature. The inhibitory activities of each isolated compound against four bacteria were evaluated and compounds 5 and 8 displayed moderate activity against the aquaculture pathogenic bacterium Vibrio anguillarum, with inhibition zone diameters of 8 and 9 mm, respectively, at 100 gg/disk. To the best of our knowledge, this is the first report on the secondary metabolites of mangrove-derived Alternaria tenuissima and also the first report of the isolation ofindole-diterpenoids from fungal genus Alternaria.
文摘The effect of some phenolic compounds recurrent in wines on technological features of Oenococcus oeni was studied in order to individuate those strains to be utilized as starter in the deacidification of aged red wines. For this purpose, the growth and the L-malic acid metabolism of 100O. oeni strains, previously isolated from different wines, was assayed in a synthetic medium added with ethanol, malic acid and phenol carboxylic (gallic, caffeic, p-coumaric and ferulic) acids or flavonoids (catechin and quercetin) at different concentrations. Results evidenced a different sensitivity of strains to each assayed compound. All the compounds restrained or stimulated the growth of 57 and 11 strains respectively, while no effect was detected on 6 strains. The remaining 26 strains showed a different behaviour: all were restrained by ferulic acid and stimulated by gallic acid and catechin. As for caffeic acid, 17 out of 26 strains were restrained, while 9 strains were stimulated. The main result obtained in this study was the establishment of a relationship between the effect of phenolic compounds on the O. oeni growth and the behaviour of the malolactic fermentation. This study may enrich the selection criteria of strains for the deacidification of aged red wines.
基金Supported by the National Natural Science Foundation of China (No. 30600382)the foundation of the Institute of Soil Science,Chinese Academy of Sciences (No. 055131)
文摘Cherry tomatoes (Lycopersicon esculentura Mill., cv. hongyangli) were hydroponically cultivated in a greenhouse to determine the effect of different nitrogen (N) forms on organic acid concentration and the activities of related enzymes involved in nitrogen and organic acid metabolism during cherry tomato fruit development. The results showed that fruit nitrate reductase (NR) activity was much higher following treatment with 100% NO3 and 75% NO3 + 25% NH+ than with 100% NH+ except at maturity. Glutamine synthetase (GS) activity trended downward during fruit development under all three treatments. Plants fed 100% NH+ had the lowest fruit citrate and malate levels at maturity, with the highest malate concentration at an early stage. The activity of phosphoenolpyruvate carboxylase (PEPC) was found to be in accord with the malate concentration with every N source. Under all three N forms, the citrate synthase (CS) activity peaked one week before the citrate concentration.
基金supported by the National Natural Science Foundation of China(31430004,31421061,31630003,31370081 and 31570072)the Science and Technology Commission of Shanghai Municipality(16490712100)
文摘Bacterial prodigiosins are red-colored secondary metabolites with multiple activities,such as anticancer,antimalarial and immunosuppressive,which hold great potential for medical applications.In this study,dramatically enhanced prodigiosins(RED) production in Streptomyces coelicolor was achieved by combinatorial metabolic engineering,including inactivation of the repressor gene ohkA,deletion of the actinorhodin(ACT) and calcium-dependent antibiotic(CDA) biosynthetic gene clusters(BGCs) and multi-copy chromosomal integration of the RED BGC.The results showed that ohkA deletion led to a 1-fold increase of RED production over the wild-type strain M145.Then,the ACT and CDA BGCs were deleted successively based on the AohkA mutant(SBJ101).To achieve multi-copy RED BGC integration,artificial ΦC31 attB site(s) were inserted simultaneously at the position where the ACT and CDA BGCs were deleted.The resulting strains SBJ102(with a single deletion of the ACT BGC and insertion of one artificial attB site) and SBJ103(with the deletion of both BGCs and insertion of two artificial attB sites) produced 1.9-and 6-fold higher RED titers than M145,respectively.Finally,the entire RED BGC was introduced into mutants from SBJ101 to SBJ103,generating three mutants(from SBJ104 to SBJ106) with chromosomal integration of one to three copies of the RED BGC.The highest RED yield was from SBJ106,which produced a maximum level of 96.8 mg g^(-1) cell dry weight,showing a 12-fold increase relative to M145.Collectively,the metabolic engineering strategies employed in this study are very efficient for the construction of high prodigiosin-producing strains.
基金Supported by the National Natural Science Foundation of China(Nos.50978122 and U0933002)
文摘A bacterial strain, Arthrobacter oxydans (B4), capable of degrading benzo[a]pyrene (BaP) in water body, was isolated from a polycyclic aromatic hydrocarbons-contaminated site. Effects of different factors, such as reaction time, pH value, temperature and organic nutrients, on BaP biodegradation by the strain B4 were studied. After 5 d treatment, the concentration of BaP in mineral salts medium was reduced to 0.318 mg L-1, compared to the initial concentration of 1.000 mg L-1. There was a process of acid formation during the degradation with pH falling from initial 7.01 to 4.61 at 5 d, so keeping the water body under slightly alkaline condition was propitious to BaP degradation. Strain B4 efficiently degraded BaP at 20 to 37 ~C with addition of organic nutrients. The biodegradation and transformation of BaP mainly occurred on cell surfaces, and extracellular secretions played an important role in these processes. Fourier transform infrared spectroscopy and gas chromatograph-mass spectrometer analyses of metabolites showed that ring cleavage occurred in the BaP degradation process and the resulting metabolically utilizable substrates were generated as sole carbon sources for B4 growth. Furthermore, mineralization extent of metabolites was verified by determining the total organic carbon and inorganic carbon in the degradation system.