Primary tosylates 1a-d were converted to the corresponding amino species 3a-d. Benzylamine was proved effective for the substitution of tosylates, using acetonitrile (MeCN) as the solvent of choice and citric acid to ...Primary tosylates 1a-d were converted to the corresponding amino species 3a-d. Benzylamine was proved effective for the substitution of tosylates, using acetonitrile (MeCN) as the solvent of choice and citric acid to remove excess of the reagent from crude products 2a-d. Debenzylation was carried out at circa (ca.) atmospheric pressure of hydrogen gas in the presence of acetic acid (AcOH). The method was also demonstrated in a demo batch experiment for the synthesis of compound 3a on a 50 g scale of 1a.展开更多
3-Deoxy-3-（p-fluorine-phenylamino）-1,2-O-isopropylidene-α-D-ribofuranose 3 was synthesized and characterized by IR, NMR and H R M S, and its crystal structure was detertnined by X-ray diffraction analysis. Crystal ...3-Deoxy-3-（p-fluorine-phenylamino）-1,2-O-isopropylidene-α-D-ribofuranose 3 was synthesized and characterized by IR, NMR and H R M S, and its crystal structure was detertnined by X-ray diffraction analysis. Crystal data for 3： monoclinic, space group P21, a=7.0403（14）, b = 6.7780（4）, c = 14.932（3） A, β= 94.74（3）°, C14H18FNO4, Mr = 283.29, V= 710.1（2） A^3, Z = 2, Dc = 1.325 g/cm^3, μ = 0.105 mm^-1, F（000） = 300, the final R = 0.0468 and wR = 0.0926 for 1969 observed reflections （I 〉 2σ（I））. Two intermolecular hydrogen bonds are observed. The absolute configuration of this molecule was confirmed by comparison with that of the original material.展开更多
Soil amino sugars have been widely used to evaluate the potential roles of microbes in mediating soil carbon(C)cycling and various pretreatment methods were used for its extraction.However,few studies assessed their p...Soil amino sugars have been widely used to evaluate the potential roles of microbes in mediating soil carbon(C)cycling and various pretreatment methods were used for its extraction.However,few studies assessed their potential influences on the soil amino sugar extraction.In this study,we investigated the effects of sample storage method and grinding on amino sugar extraction across different climatic zones and land uses.Results showed that the concentrations of soil amino sugars varied greatly among sample pretreatments and their impacts were highly dependent on climatic condition and land use.Specifically,higher concentrations of amino sugars were extracted from field-moist samples than dried samples in subtropical grassland,temperate forest and arable land with no significant differences among storage methods for the samples from subtropical forest,arable land,and temperate grassland.Moreover,grinding improved the extraction efficiency of amino sugars for the dried soils.Due to the reduced extraction concentration in dried soils,field-moist samples were recommended in priority.For the dried soils used for the long-term storage,grinding can be an option to improve the extraction efficiency.Such information will be valuable for reducing the uncertainty and improving the accuracy during the determination of soil amino sugars.展开更多
Land use change affects the balance of organic carbon(C)reserves and the global C cycle.Microbial residues are essential constituents of stable soil organic C(SOC).However,it remains unclear how microbial residue chan...Land use change affects the balance of organic carbon(C)reserves and the global C cycle.Microbial residues are essential constituents of stable soil organic C(SOC).However,it remains unclear how microbial residue changes over time following afforestation.In this study,16-,23-,52-,and 62-year-old Mongolian pine stands and 16-year-old cropland were studied in the Horqin Sandy Land,China.We analyzed changes in SOC,amino sugar content,and microbial parameters to assess how microbial communities influence soil C transformation and preservation.The results showed that SOC storage increased with stand age in the early stage of afforestation but remained unchanged at about 1.27-1.29 kg/m2 after 52 a.Moreover,there were consistent increases in amino sugars and microbial residues with increasing stand age.As stand age increased from 16 to 62 a,soil pH decreased from 6.84 to 5.71,and the concentration of total amino sugars increased from 178.53 to 509.99 mg/kg.A significant negative correlation between soil pH and the concentration of specific and total amino sugars was observed,indicating that the effects of soil acidification promote amino sugar stabilization during afforestation.In contrast to the Mongolian pine plantation of the same age,the cropland accumulated more SOC and microbial residues because of fertilizer application.Across Mongolian pine plantation with different ages,there was no significant change in calculated contribution of bacterial or fungal residues to SOC,suggesting that fungi were consistently the dominant contributors to SOC with increasing time.Our results indicate that afforestation in the Horqin Sandy Land promotes efficient microbial growth and residue accumulation in SOC stocks and has a consistent positive impact on SOC persistence.展开更多
This paper presents the investigation on biosynthesis of high-value-added amino acids and sugars labeled uniformly with stable isotope 13C by microalga Spirulina (Arthrospira) maxima in a parallelepiped photobioreacto...This paper presents the investigation on biosynthesis of high-value-added amino acids and sugars labeled uniformly with stable isotope 13C by microalga Spirulina (Arthrospira) maxima in a parallelepiped photobioreactor. The kinetic data of both batch and continuous cultures with characterization of the amino acids and sugars are shown. The continuous culture without nutrients deficiency is for biosynthesis of amino acids, with tyrosine as one of the principal constituents, and the batch culture with deficiency in nitrogen is for biosynthesis of labeled glucose that is up to 64% versus dry mass of cells.展开更多
The title compound 2 was synthesized by the reaction of 3-keto-D-xylose with O-C6H4NH2NH2 and characterized by IR, NMR and HRMS, and its crystal structure was determined by X-ray diffraction analysis. The crystal is o...The title compound 2 was synthesized by the reaction of 3-keto-D-xylose with O-C6H4NH2NH2 and characterized by IR, NMR and HRMS, and its crystal structure was determined by X-ray diffraction analysis. The crystal is of orthorhombic system （C21H22N2O5, Mr = 382.41）, space group P2 1 2 1 2 1 with α = 10.140（2）, b = 10.802（2）, c = 17.840（4） A, β = 90°, V = 1954.1（7）A^3, Z = 4, Dc = 1.300 g/cm^3, F（000） = 808, μ = 0.094 mm^-1, the final R = 0.0354 and wR = 0.0514 for 1924 observed reflections （I 〉 2σ（I））. One intermolecular and one intramolecular hydrogen bonds were found. The absolute configuration of this molecule was confirmed by comparison with that of the original material.展开更多
文摘Primary tosylates 1a-d were converted to the corresponding amino species 3a-d. Benzylamine was proved effective for the substitution of tosylates, using acetonitrile (MeCN) as the solvent of choice and citric acid to remove excess of the reagent from crude products 2a-d. Debenzylation was carried out at circa (ca.) atmospheric pressure of hydrogen gas in the presence of acetic acid (AcOH). The method was also demonstrated in a demo batch experiment for the synthesis of compound 3a on a 50 g scale of 1a.
基金Supported by the National Natural Science Foundation of China (No. 20472075)
文摘3-Deoxy-3-（p-fluorine-phenylamino）-1,2-O-isopropylidene-α-D-ribofuranose 3 was synthesized and characterized by IR, NMR and H R M S, and its crystal structure was detertnined by X-ray diffraction analysis. Crystal data for 3： monoclinic, space group P21, a=7.0403（14）, b = 6.7780（4）, c = 14.932（3） A, β= 94.74（3）°, C14H18FNO4, Mr = 283.29, V= 710.1（2） A^3, Z = 2, Dc = 1.325 g/cm^3, μ = 0.105 mm^-1, F（000） = 300, the final R = 0.0468 and wR = 0.0926 for 1969 observed reflections （I 〉 2σ（I））. Two intermolecular hydrogen bonds are observed. The absolute configuration of this molecule was confirmed by comparison with that of the original material.
基金supported by the National Natural Science Foundation of China(Grant Nos.41771278,41571249 and U1701246)Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Grant No.GML2019-ZD0408)+2 种基金Science and Technology Program of Guangzhou City(Grant No.201707010344)Open Foundation of the State Key Laboratory of Loess and Quaternary Geology(Grant No.SKLLQG1917)Youth Innovation Promotion Association of Chinese Academy of Sciences.
文摘Soil amino sugars have been widely used to evaluate the potential roles of microbes in mediating soil carbon(C)cycling and various pretreatment methods were used for its extraction.However,few studies assessed their potential influences on the soil amino sugar extraction.In this study,we investigated the effects of sample storage method and grinding on amino sugar extraction across different climatic zones and land uses.Results showed that the concentrations of soil amino sugars varied greatly among sample pretreatments and their impacts were highly dependent on climatic condition and land use.Specifically,higher concentrations of amino sugars were extracted from field-moist samples than dried samples in subtropical grassland,temperate forest and arable land with no significant differences among storage methods for the samples from subtropical forest,arable land,and temperate grassland.Moreover,grinding improved the extraction efficiency of amino sugars for the dried soils.Due to the reduced extraction concentration in dried soils,field-moist samples were recommended in priority.For the dried soils used for the long-term storage,grinding can be an option to improve the extraction efficiency.Such information will be valuable for reducing the uncertainty and improving the accuracy during the determination of soil amino sugars.
基金funded by the Fundamental Research Funds of Chinese Academy of Forestry(CAF)(CAFYBB2020QD002-2).
文摘Land use change affects the balance of organic carbon(C)reserves and the global C cycle.Microbial residues are essential constituents of stable soil organic C(SOC).However,it remains unclear how microbial residue changes over time following afforestation.In this study,16-,23-,52-,and 62-year-old Mongolian pine stands and 16-year-old cropland were studied in the Horqin Sandy Land,China.We analyzed changes in SOC,amino sugar content,and microbial parameters to assess how microbial communities influence soil C transformation and preservation.The results showed that SOC storage increased with stand age in the early stage of afforestation but remained unchanged at about 1.27-1.29 kg/m2 after 52 a.Moreover,there were consistent increases in amino sugars and microbial residues with increasing stand age.As stand age increased from 16 to 62 a,soil pH decreased from 6.84 to 5.71,and the concentration of total amino sugars increased from 178.53 to 509.99 mg/kg.A significant negative correlation between soil pH and the concentration of specific and total amino sugars was observed,indicating that the effects of soil acidification promote amino sugar stabilization during afforestation.In contrast to the Mongolian pine plantation of the same age,the cropland accumulated more SOC and microbial residues because of fertilizer application.Across Mongolian pine plantation with different ages,there was no significant change in calculated contribution of bacterial or fungal residues to SOC,suggesting that fungi were consistently the dominant contributors to SOC with increasing time.Our results indicate that afforestation in the Horqin Sandy Land promotes efficient microbial growth and residue accumulation in SOC stocks and has a consistent positive impact on SOC persistence.
基金Supported by the Scholarship of Faculte Polytechnique de Mons, Belgium and by the Fund for Scholars Returning from Abroad.
文摘This paper presents the investigation on biosynthesis of high-value-added amino acids and sugars labeled uniformly with stable isotope 13C by microalga Spirulina (Arthrospira) maxima in a parallelepiped photobioreactor. The kinetic data of both batch and continuous cultures with characterization of the amino acids and sugars are shown. The continuous culture without nutrients deficiency is for biosynthesis of amino acids, with tyrosine as one of the principal constituents, and the batch culture with deficiency in nitrogen is for biosynthesis of labeled glucose that is up to 64% versus dry mass of cells.
基金supported by the National Natural Science Foundation of China (No. 20472075)
文摘The title compound 2 was synthesized by the reaction of 3-keto-D-xylose with O-C6H4NH2NH2 and characterized by IR, NMR and HRMS, and its crystal structure was determined by X-ray diffraction analysis. The crystal is of orthorhombic system （C21H22N2O5, Mr = 382.41）, space group P2 1 2 1 2 1 with α = 10.140（2）, b = 10.802（2）, c = 17.840（4） A, β = 90°, V = 1954.1（7）A^3, Z = 4, Dc = 1.300 g/cm^3, F（000） = 808, μ = 0.094 mm^-1, the final R = 0.0354 and wR = 0.0514 for 1924 observed reflections （I 〉 2σ（I））. One intermolecular and one intramolecular hydrogen bonds were found. The absolute configuration of this molecule was confirmed by comparison with that of the original material.
