A new purine nucleoside coupled with an amino acid derivative, N^2-（l-methoxycarbonylethyl）guanosine 1, along with β- carboline and russulaceramide was isolated from the fruiting bodies of Amanita exitialis, a newl...A new purine nucleoside coupled with an amino acid derivative, N^2-（l-methoxycarbonylethyl）guanosine 1, along with β- carboline and russulaceramide was isolated from the fruiting bodies of Amanita exitialis, a newly described poisonous mushroom. Its structure was elucidated by spectroscopic methods. This is the first report of naturally occurring nucleosides in which an a-amino acid derivative is bonded through its a-amino nitrogen to a nucleobase aglycone by a C-N bond. The new compound was found to be toxic in brine shrimp lethality test （BST）. C 2009 Published by Elsevier B.V. on behalf of Chinese Chemical Society.展开更多
Mutagenesis and retrotransposons have a close relationship, but little attention has been paid yet to the activity of retrotransposons produced by physical mutagens. The variation of retrotransposon WIS 2-1A activity ...Mutagenesis and retrotransposons have a close relationship, but little attention has been paid yet to the activity of retrotransposons produced by physical mutagens. The variation of retrotransposon WIS 2-1A activity in wheat （Triticum aestivum L.） embryos at three different growth times （30 h, 45 h and 60 h） was investigated after they had been treated with N^＋ implantation in a vacuum of 5× 10^-2 Pa and irradiation by ^60Coγ-ray respectively. For each of the three growth times the expression of WIS 2-1A showed almost entirely a same trend of downregulation, upregulation, then downregulation, and upregulation again with the increase in dose of N^＋ implantation, but the expression appeared irregular with the increase in irradiation of ^60Coγ-ray. In conclusion, the acutely activating effect of WIS 2-1A stimulated by vacuum and high dose N^＋ implantation within a shorter incubation time may provide a convenient tool to advance the research on mutagenic breeding and function genes.展开更多
In this paper,the truncated Painlev′e analysis,nonlocal symmetry,Bcklund transformation of the（2＋1）-dimensional modified Bogoyavlenskii–Schiff equation are presented.Then the nonlocal symmetry is localized to the...In this paper,the truncated Painlev′e analysis,nonlocal symmetry,Bcklund transformation of the（2＋1）-dimensional modified Bogoyavlenskii–Schiff equation are presented.Then the nonlocal symmetry is localized to the corresponding nonlocal group by the prolonged system.In addition,the（2＋1）-dimensional modified Bogoyavlenskii–Schiff is proved consistent Riccati expansion（CRE） solvable.As a result,the soliton–cnoidal wave interaction solutions of the equation are explicitly given,which are difficult to find by other traditional methods.Moreover figures are given out to show the properties of the explicit analytic interaction solutions.展开更多
AIM： To investigate whether nicotinamide overload plays a role in type 2 diabetes. METHODS： Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of...AIM： To investigate whether nicotinamide overload plays a role in type 2 diabetes. METHODS： Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of nicotinamide and N^1-methylnicotinamide on glucose metabolism, plasma HzO2 levels and tissue nicotinamide adenine dinucleotide （NAD） contents of adult Sprague-Dawley rats were observed. The role of human sweat glands and rat skin in nicotinamide metabolism was investigated using sauna and burn injury, respectively. RESULTS： Diabetic subjects had significantly higher plasma N^1-methylnicotinamide levels 5 h after a 100-mg nicotinamide load than the non-diabetic subjects （0.89 ± 0.13 μmol/L vs 0.6 ± 0.13 μmol/L, P 〈 0.001）. Cumulative doses of nicotinamide （2 g/kg） significantly increased rat plasma Nl-methylnicotinamide concentrations associated with severe insulin resistance, which was mimicked by Nl-methy-Inicotinamide. Moreover, cumulative exposure to N^1- methylnicotinamide （2 g/kg） markedly reduced rat muscle and liver NAD contents and erythrocyte NAD/ NADH ratio, and increased plasma H2O2 levels. Decrease in NAD/NADH ratio and increase in H2O2 generation were also observed in human erythrocytes after exposure to N^1-methylnicotinamide in vitro. Sweating eliminated excessive nicotinamide （5.3-fold increase in sweat nicotinamide concentration 1 h after a 100-mg nicotinamide load）. Skin damage or aldehyde oxidase inhibition with tamoxifen or olanzapine, both being notorious for impairing glucose tolerance, delayed N^1- methylnicotinamide clearance. CONCLUSION： These findings suggest that nicotinamide overload, which induced an increase in plasma N^1- methylnicotinamide, associated with oxidative stress and insulin resistance, plays a role in type 2 diabetes.展开更多
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(No.KSCX2-YW-N-036).
文摘A new purine nucleoside coupled with an amino acid derivative, N^2-（l-methoxycarbonylethyl）guanosine 1, along with β- carboline and russulaceramide was isolated from the fruiting bodies of Amanita exitialis, a newly described poisonous mushroom. Its structure was elucidated by spectroscopic methods. This is the first report of naturally occurring nucleosides in which an a-amino acid derivative is bonded through its a-amino nitrogen to a nucleobase aglycone by a C-N bond. The new compound was found to be toxic in brine shrimp lethality test （BST）. C 2009 Published by Elsevier B.V. on behalf of Chinese Chemical Society.
基金supported by National Natural Science Foundation of China(Nos.10505018,30800204)the Chinese Ministry of Agriculture(No.200803034)
文摘Mutagenesis and retrotransposons have a close relationship, but little attention has been paid yet to the activity of retrotransposons produced by physical mutagens. The variation of retrotransposon WIS 2-1A activity in wheat （Triticum aestivum L.） embryos at three different growth times （30 h, 45 h and 60 h） was investigated after they had been treated with N^＋ implantation in a vacuum of 5× 10^-2 Pa and irradiation by ^60Coγ-ray respectively. For each of the three growth times the expression of WIS 2-1A showed almost entirely a same trend of downregulation, upregulation, then downregulation, and upregulation again with the increase in dose of N^＋ implantation, but the expression appeared irregular with the increase in irradiation of ^60Coγ-ray. In conclusion, the acutely activating effect of WIS 2-1A stimulated by vacuum and high dose N^＋ implantation within a shorter incubation time may provide a convenient tool to advance the research on mutagenic breeding and function genes.
基金Project supported by the Global Change Research Program of China(Grant No.2015CB953904)the National Natural Science Foundation of China(Grant Nos.11275072 and 11435005)+2 种基金the Doctoral Program of Higher Education of China(Grant No.20120076110024)the Network Information Physics Calculation of Basic Research Innovation Research Group of China(Grant No.61321064)the Fund from Shanghai Collaborative Innovation Center of Trustworthy Software for Internet of Things(Grant No.ZF1213)
文摘In this paper,the truncated Painlev′e analysis,nonlocal symmetry,Bcklund transformation of the（2＋1）-dimensional modified Bogoyavlenskii–Schiff equation are presented.Then the nonlocal symmetry is localized to the corresponding nonlocal group by the prolonged system.In addition,the（2＋1）-dimensional modified Bogoyavlenskii–Schiff is proved consistent Riccati expansion（CRE） solvable.As a result,the soliton–cnoidal wave interaction solutions of the equation are explicitly given,which are difficult to find by other traditional methods.Moreover figures are given out to show the properties of the explicit analytic interaction solutions.
基金Supported by National Natural Science Foundation of China, No. 30570665the Foundation of Dalian Technology Bureau, No. 2008E13SF182the Foundation of Key Laboratory of Education Department of Liaoning Province,No. 2009S005
文摘AIM： To investigate whether nicotinamide overload plays a role in type 2 diabetes. METHODS： Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of nicotinamide and N^1-methylnicotinamide on glucose metabolism, plasma HzO2 levels and tissue nicotinamide adenine dinucleotide （NAD） contents of adult Sprague-Dawley rats were observed. The role of human sweat glands and rat skin in nicotinamide metabolism was investigated using sauna and burn injury, respectively. RESULTS： Diabetic subjects had significantly higher plasma N^1-methylnicotinamide levels 5 h after a 100-mg nicotinamide load than the non-diabetic subjects （0.89 ± 0.13 μmol/L vs 0.6 ± 0.13 μmol/L, P 〈 0.001）. Cumulative doses of nicotinamide （2 g/kg） significantly increased rat plasma Nl-methylnicotinamide concentrations associated with severe insulin resistance, which was mimicked by Nl-methy-Inicotinamide. Moreover, cumulative exposure to N^1- methylnicotinamide （2 g/kg） markedly reduced rat muscle and liver NAD contents and erythrocyte NAD/ NADH ratio, and increased plasma H2O2 levels. Decrease in NAD/NADH ratio and increase in H2O2 generation were also observed in human erythrocytes after exposure to N^1-methylnicotinamide in vitro. Sweating eliminated excessive nicotinamide （5.3-fold increase in sweat nicotinamide concentration 1 h after a 100-mg nicotinamide load）. Skin damage or aldehyde oxidase inhibition with tamoxifen or olanzapine, both being notorious for impairing glucose tolerance, delayed N^1- methylnicotinamide clearance. CONCLUSION： These findings suggest that nicotinamide overload, which induced an increase in plasma N^1- methylnicotinamide, associated with oxidative stress and insulin resistance, plays a role in type 2 diabetes.
