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
Sucrose, raffinose, and stachyose are important soluble sugars in soybean [Glycine max (L.) Merr.] seeds. Seed sucrose is a desirable trait for taste and flavor. Raffinose and stachyose are undesirable in diets of mon...Sucrose, raffinose, and stachyose are important soluble sugars in soybean [Glycine max (L.) Merr.] seeds. Seed sucrose is a desirable trait for taste and flavor. Raffinose and stachyose are undesirable in diets of monogastric animals, acting as anti-nutritional factors that cause flatulence and abdominal discomfort. Therefore, reducing raffinose and stachyose biosynthesis is considered as a key quality trait goal in soy food and feed industries. The objective of this study was to identify genomic regions containing quantitative trait loci (QTL) controlling sucrose, raffinose, and stachyose in a set of 92 F5:7 recombinant inbred lines (RILs) derived from a cross between the lines “MD96-5722” and “Spencer” by using 5376 Single Nucleotide Polymorphism (SNP) markers from the Illumina Infinium SoySNP6K BeadChip array. Fourteen significant QTL were identified and mapped on eight different linkage groups (LGs) and chromosomes (Chr). Three QTL for seed sucrose content were identified on LGs N (Chr3), K (Chr9), and E (Chr15). Seven QTL were identified for raffinose content on LGs D1a (Chr1), N (Chr3), C2 (Chr6), K (Chr9), B2 (Chr14), and J (Chr16). Four QTL for stachyose content were identified on LG D1a (Chr1), C2 (Chr6), H (Chr12), and B2 (Chr14). Selection for beneficial alleles of these QTLs could facilitate breeding strategies to develop soybean lines with higher concentrations of sucrose and lower levels of raffinose and stachyose.展开更多
The ab initio method has been used to study the 1-3 H transfer reaction on formamidine substituted by halogen. The calculation results show that the substituted halogen has two effects on the 1-3 H transfer reaction...The ab initio method has been used to study the 1-3 H transfer reaction on formamidine substituted by halogen. The calculation results show that the substituted halogen has two effects on the 1-3 H transfer reaction: decreasing the activation energy and stabilizing the C=N double bond owing to the conjugative effect of p-π-p of products and transition states.展开更多
An efficient synthesis of 3,4-dihydropyrimidine 2 （1H）-ones and thiones （3,4-DHPMs） core was prepared by one-pot threecomponent Biginelli condensation and which was catalyzed by trifluoromethane sulfonic acid. The...An efficient synthesis of 3,4-dihydropyrimidine 2 （1H）-ones and thiones （3,4-DHPMs） core was prepared by one-pot threecomponent Biginelli condensation and which was catalyzed by trifluoromethane sulfonic acid. The classical BigneUi reaction has been extended by the use of N-substituted benzoxazolyl semicarbazides and thiosemicarbazides and this method has the advantage of excellent yields and short reaction times. ？2009 M. Saranga Pard. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
BaFeO_(3-δ)-derived perovskites are promising cathodes for intermediate temperature solid oxide fuel cells.The activity of these perovskites depends on the number of oxygen vacancies in their lattice,which can be tun...BaFeO_(3-δ)-derived perovskites are promising cathodes for intermediate temperature solid oxide fuel cells.The activity of these perovskites depends on the number of oxygen vacancies in their lattice,which can be tuned by cationic substitution.Our first-principle calculations show that Ag is a promising substitute for the Fe site,resulting in a reduced oxygen vacancy formation energy compared with the pristine BaFeO_(3-δ).Ag has limited solubility in perovskites,and its introduction generates an Ag metal secondary phase,which influences the cathode performances.In this work,we investigate the matter,using a Ba0:9La0:1Fe_(1-x)AgxO_(3-δ)series of materials as a case study.Acknowledging the limited solubility of Ag in Ba0:9La0:1Fe_(1-x)AgxO_(3-δ),we aim to distinguish the effects of Ag substitution from those of the Ag secondary phase.We observed that Ag substitution increases the number of oxygen vacancies,confirming our calculations,and facilitates the oxygen incorporation.However,Ag substitution lowers the number of holes,in this way reducing the electronic p-type conductivity.On the other hand,Ag metal positively affects the electronic conductivity and helps the redistribution of the electronic charge at the cathode-electrolyte interface.展开更多
AIM To investigate possible changes of blood glucose levels after oral intake of lactulose in healthy subjects.METHODS The study was performed as prospective, randomized, two-part study with 4-way cross-over design wi...AIM To investigate possible changes of blood glucose levels after oral intake of lactulose in healthy subjects.METHODS The study was performed as prospective, randomized, two-part study with 4-way cross-over design with n = 12 in each study arm. Capillary blood glucose levels were determined over a time period of 180 min after intake of a single dose of 10 g or 20 g lactulose provided as crystal or liquid formulation. During the manufacturing process of lactulose, impurities with sugars(e.g., lactose, fructose, galactose) occur. Water and 20 g glucose were used as control and reference. Because lactulose is used as a functional food ingredient, it may also be consumed by people with impaired glucose tolerance, including diabetics. Therefore, it is of interest to determine whether the described carbohydrate impurities may increase blood glucose levels after ingestion. RESULTS The blood glucose concentration-time curves after intake of 10 g lactulose, 20 g lactulose, and water were almost identical. None of the three applications showed any changes in blood glucose levels. After intake of 20 g glucose, blood glucose concentration increased by approximately 3 mmol/L(mean Cmax = 8.3 mmol/L), reaching maximum levels after approximately 30 min and returning to baseline within approximately 90 min, which was significantly different to the corresponding 20 g lactulose formulations(P < 0.0001). Comparing the two lactulose formulations, crystals and liquid, in the dosage of 10 g and 20 g, there was no difference in the blood glucose profile and calculated pharmacokinetic parameters despite the different amounts of carbohydrate impurities(1.5% for crystals and 26.45% for liquid). Anyhow, the absolute amount of single sugars was low with 0.3 g in crystals and 5.29 g in liquid formulation in the 20 g dosages. Lactulose was well tolerated by most volunteers, and only some reported mild to moderate mainly gastrointestinal side effects. CONCLUSION The unchanged blood glucose levels after lactulose intake in healthy subjects suggest its safe use in subjects with impaired glucose tolerance.展开更多
Toxicities （-1gEC50） of 16 phenolic compounds against Q67 were determined, and structural parameters as well as thermodynamic parameters of these compounds were obtained through fully optimized calculations by using...Toxicities （-1gEC50） of 16 phenolic compounds against Q67 were determined, and structural parameters as well as thermodynamic parameters of these compounds were obtained through fully optimized calculations by using B3LYP method of density functional theory （DFT） at the 6-311G^＊＊ level. Moreover, a 3-parameter （molecular average polarizability （α）, heat energy corrected value （Eth） and the most positive hydrogen atomic charge （qH^＋）） correlation model with R^2 = 0.981 and q^2 = 0.967 to predict -1gEC50 was obtained from experimental data based on the above-mentioned parameters as theoretical descriptors. Therein a was the most significant on -1gEC50. Variance Inflation Factors （VIF）, t-value and cross-validation were applied to verify the model, confirming that the resultant model has fairly better stability and predictive ability to predict -1gEC50 of similar compounds.展开更多
A phosphrous-containing poly（aryl ether ketone） was synthesized derived from bisphenol-A and bis[4-（4- fluorobenzoyl）phenyl] phenyl phosphine oxide （FPPPO） by nucleophilic substitution reaction. The structure of...A phosphrous-containing poly（aryl ether ketone） was synthesized derived from bisphenol-A and bis[4-（4- fluorobenzoyl）phenyl] phenyl phosphine oxide （FPPPO） by nucleophilic substitution reaction. The structure of the polymer was characterized by FT-IR, ^1H-NMR and ^31p-NMR. The thermal property of the PAEK was measured by DSC and TGA. The glass transition temperature （Tg） of the polymer was 205℃, and the 5% weight loss temperature under nitrogen was 475℃. Good solubility of the polymer in organic solvents, such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide and chloroalkanes was observed, flexible film was obtained from the polymer＇s CH2Cl2 solution. The limiting oxygen index （LOI） of the PAEK was 40, which indicated that organic phosphorus moiety can offer good flame retardant property to the polymer.展开更多
To investigate the differences in taste characteristics and antioxidant properties of four types of tea substitutes.After sensory review and electronic tongue indicated that the taste characteristics of the four subst...To investigate the differences in taste characteristics and antioxidant properties of four types of tea substitutes.After sensory review and electronic tongue indicated that the taste characteristics of the four substitute teas were sweetness,bitterness and astringency.There were a total of 136 flavonoid metabolites in 12 categories and 12 sugar metabolites were identified in the four substitute teas with ultra-performance liquid chromatography tandem-mass spectrometry metabolomics targeted detection.Flavonoids were significantly positively correlated with antioxidant properties,among them,15 were positively associated with clearing ABTS radicals and five were positively associated with clearing DPPH radicals,and sugars were significantly negatively correlated with antioxidant properties.The antioxidant properties were in the following order:TC>KD>LY>QQ.The conclusion is that significant differences in the content of flavonoids and sugar metabolites are the main reasons for the formation of the flavour characteristics and antioxidant differences of the four substitute teas.展开更多
Chiral 4-[(2-isopropyl-5-methylcyclohexyl)oxo]-4-oxobutanoic acid reacts with substituted anilines to produce amides 1-6 in high yields. Resulted amides 1-6 were investigated for their antifungal and antibacterial act...Chiral 4-[(2-isopropyl-5-methylcyclohexyl)oxo]-4-oxobutanoic acid reacts with substituted anilines to produce amides 1-6 in high yields. Resulted amides 1-6 were investigated for their antifungal and antibacterial activities. Compounds 2 (96.5%) against Aspergillus fumigatus and 6 (93.7%) against Helminthosporium sativum demonstrated excellent activities. However, compounds 3 (37.6%) against Bacillus subtilis, 4 (33.2%) against Pseudomonas aurignosa, 5 against Klebsiella pneumonia demonstrated excellent growth inhibition potential.展开更多
Investigation of the substitution process can provide a better understanding of the superconducting mechanisms in cuprous oxide materials. In this work the effects of substitution Lanthanum (La) for Gadolinium (Gd) on...Investigation of the substitution process can provide a better understanding of the superconducting mechanisms in cuprous oxide materials. In this work the effects of substitution Lanthanum (La) for Gadolinium (Gd) on the structure and oxygen content for x = 0.0 - 0.5 in the compound Gd1-xLaxBa2Cu3O7-δ (GLBCO-123 phase) have been investigated. Samples were synthesized by using a wet-mixing method from powders of Gd2O2, La2O2, BaO, CuO, and solution of HNO3. Based on the analysis of XRD data and SEM-EDXA, it confirms that the sample has formed the GLBCO-123 phase, as expected. It has been obtained that the lattice parameters a and c are increased while the parameter b is slightly decreased with increasing content of Lanthanum. The oxygen content slightly decreased and structure of the Gd1-xLaxBa2Cu3O7-δ phase changed from orthorhombic to tetragonal with increasing the content of Lanthanum.展开更多
In an effort to improve the performance of superconductors in the field and high temperatures it is important to study the superconducting mechanism. For this reason, the cation substitution can be conducted. One of t...In an effort to improve the performance of superconductors in the field and high temperatures it is important to study the superconducting mechanism. For this reason, the cation substitution can be conducted. One of the high Tc superconductors Gd1Ba2Cu3O7−δ phase with Sr substitution has been synthesized, i.e. Gd1(Ba2−xSrx)Cu3O7−δ compound. The sample was synthesized by using a solid-state reaction method with a wet mixing, sintered for 12 hours at temperature 900°C. The synthesis results are characterized by using XRD. The results of Match-3 software analysis showed high (higher 85%) Gd1Ba2Cu3O7−δ phase was formed. The Sr substitution causes changes to the structure, i.e. the lattice parameters a, b and c, where the orthorhombicity tends to decrease with increasing Sr content. Refinement results show that based on the oxygen occupancy, the total oxygen content tends to increase.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.
文摘Sucrose, raffinose, and stachyose are important soluble sugars in soybean [Glycine max (L.) Merr.] seeds. Seed sucrose is a desirable trait for taste and flavor. Raffinose and stachyose are undesirable in diets of monogastric animals, acting as anti-nutritional factors that cause flatulence and abdominal discomfort. Therefore, reducing raffinose and stachyose biosynthesis is considered as a key quality trait goal in soy food and feed industries. The objective of this study was to identify genomic regions containing quantitative trait loci (QTL) controlling sucrose, raffinose, and stachyose in a set of 92 F5:7 recombinant inbred lines (RILs) derived from a cross between the lines “MD96-5722” and “Spencer” by using 5376 Single Nucleotide Polymorphism (SNP) markers from the Illumina Infinium SoySNP6K BeadChip array. Fourteen significant QTL were identified and mapped on eight different linkage groups (LGs) and chromosomes (Chr). Three QTL for seed sucrose content were identified on LGs N (Chr3), K (Chr9), and E (Chr15). Seven QTL were identified for raffinose content on LGs D1a (Chr1), N (Chr3), C2 (Chr6), K (Chr9), B2 (Chr14), and J (Chr16). Four QTL for stachyose content were identified on LG D1a (Chr1), C2 (Chr6), H (Chr12), and B2 (Chr14). Selection for beneficial alleles of these QTLs could facilitate breeding strategies to develop soybean lines with higher concentrations of sucrose and lower levels of raffinose and stachyose.
基金Supported by the Yunnan Provincial Science and Technology Department (2003A0003M)
文摘The ab initio method has been used to study the 1-3 H transfer reaction on formamidine substituted by halogen. The calculation results show that the substituted halogen has two effects on the 1-3 H transfer reaction: decreasing the activation energy and stabilizing the C=N double bond owing to the conjugative effect of p-π-p of products and transition states.
文摘An efficient synthesis of 3,4-dihydropyrimidine 2 （1H）-ones and thiones （3,4-DHPMs） core was prepared by one-pot threecomponent Biginelli condensation and which was catalyzed by trifluoromethane sulfonic acid. The classical BigneUi reaction has been extended by the use of N-substituted benzoxazolyl semicarbazides and thiosemicarbazides and this method has the advantage of excellent yields and short reaction times. ？2009 M. Saranga Pard. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金The authors gratefully acknowledge the Research Grant Council of Hong Kong for support through the projects 16201820,and 16206019.
文摘BaFeO_(3-δ)-derived perovskites are promising cathodes for intermediate temperature solid oxide fuel cells.The activity of these perovskites depends on the number of oxygen vacancies in their lattice,which can be tuned by cationic substitution.Our first-principle calculations show that Ag is a promising substitute for the Fe site,resulting in a reduced oxygen vacancy formation energy compared with the pristine BaFeO_(3-δ).Ag has limited solubility in perovskites,and its introduction generates an Ag metal secondary phase,which influences the cathode performances.In this work,we investigate the matter,using a Ba0:9La0:1Fe_(1-x)AgxO_(3-δ)series of materials as a case study.Acknowledging the limited solubility of Ag in Ba0:9La0:1Fe_(1-x)AgxO_(3-δ),we aim to distinguish the effects of Ag substitution from those of the Ag secondary phase.We observed that Ag substitution increases the number of oxygen vacancies,confirming our calculations,and facilitates the oxygen incorporation.However,Ag substitution lowers the number of holes,in this way reducing the electronic p-type conductivity.On the other hand,Ag metal positively affects the electronic conductivity and helps the redistribution of the electronic charge at the cathode-electrolyte interface.
文摘AIM To investigate possible changes of blood glucose levels after oral intake of lactulose in healthy subjects.METHODS The study was performed as prospective, randomized, two-part study with 4-way cross-over design with n = 12 in each study arm. Capillary blood glucose levels were determined over a time period of 180 min after intake of a single dose of 10 g or 20 g lactulose provided as crystal or liquid formulation. During the manufacturing process of lactulose, impurities with sugars(e.g., lactose, fructose, galactose) occur. Water and 20 g glucose were used as control and reference. Because lactulose is used as a functional food ingredient, it may also be consumed by people with impaired glucose tolerance, including diabetics. Therefore, it is of interest to determine whether the described carbohydrate impurities may increase blood glucose levels after ingestion. RESULTS The blood glucose concentration-time curves after intake of 10 g lactulose, 20 g lactulose, and water were almost identical. None of the three applications showed any changes in blood glucose levels. After intake of 20 g glucose, blood glucose concentration increased by approximately 3 mmol/L(mean Cmax = 8.3 mmol/L), reaching maximum levels after approximately 30 min and returning to baseline within approximately 90 min, which was significantly different to the corresponding 20 g lactulose formulations(P < 0.0001). Comparing the two lactulose formulations, crystals and liquid, in the dosage of 10 g and 20 g, there was no difference in the blood glucose profile and calculated pharmacokinetic parameters despite the different amounts of carbohydrate impurities(1.5% for crystals and 26.45% for liquid). Anyhow, the absolute amount of single sugars was low with 0.3 g in crystals and 5.29 g in liquid formulation in the 20 g dosages. Lactulose was well tolerated by most volunteers, and only some reported mild to moderate mainly gastrointestinal side effects. CONCLUSION The unchanged blood glucose levels after lactulose intake in healthy subjects suggest its safe use in subjects with impaired glucose tolerance.
基金supported by the Natural Science Foundation of Zhejiang Province (No. 2008Y507280)
文摘Toxicities （-1gEC50） of 16 phenolic compounds against Q67 were determined, and structural parameters as well as thermodynamic parameters of these compounds were obtained through fully optimized calculations by using B3LYP method of density functional theory （DFT） at the 6-311G^＊＊ level. Moreover, a 3-parameter （molecular average polarizability （α）, heat energy corrected value （Eth） and the most positive hydrogen atomic charge （qH^＋）） correlation model with R^2 = 0.981 and q^2 = 0.967 to predict -1gEC50 was obtained from experimental data based on the above-mentioned parameters as theoretical descriptors. Therein a was the most significant on -1gEC50. Variance Inflation Factors （VIF）, t-value and cross-validation were applied to verify the model, confirming that the resultant model has fairly better stability and predictive ability to predict -1gEC50 of similar compounds.
基金This work was supported by the National Natural Science Foundation of China(No.50203008).
文摘A phosphrous-containing poly（aryl ether ketone） was synthesized derived from bisphenol-A and bis[4-（4- fluorobenzoyl）phenyl] phenyl phosphine oxide （FPPPO） by nucleophilic substitution reaction. The structure of the polymer was characterized by FT-IR, ^1H-NMR and ^31p-NMR. The thermal property of the PAEK was measured by DSC and TGA. The glass transition temperature （Tg） of the polymer was 205℃, and the 5% weight loss temperature under nitrogen was 475℃. Good solubility of the polymer in organic solvents, such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide and chloroalkanes was observed, flexible film was obtained from the polymer＇s CH2Cl2 solution. The limiting oxygen index （LOI） of the PAEK was 40, which indicated that organic phosphorus moiety can offer good flame retardant property to the polymer.
基金The Guizhou Provincial Science and Technology Support Project,QKHBZ[2021]109 general.No.4014 of the Middle Diversion of Guizhou[2020].
文摘To investigate the differences in taste characteristics and antioxidant properties of four types of tea substitutes.After sensory review and electronic tongue indicated that the taste characteristics of the four substitute teas were sweetness,bitterness and astringency.There were a total of 136 flavonoid metabolites in 12 categories and 12 sugar metabolites were identified in the four substitute teas with ultra-performance liquid chromatography tandem-mass spectrometry metabolomics targeted detection.Flavonoids were significantly positively correlated with antioxidant properties,among them,15 were positively associated with clearing ABTS radicals and five were positively associated with clearing DPPH radicals,and sugars were significantly negatively correlated with antioxidant properties.The antioxidant properties were in the following order:TC>KD>LY>QQ.The conclusion is that significant differences in the content of flavonoids and sugar metabolites are the main reasons for the formation of the flavour characteristics and antioxidant differences of the four substitute teas.
文摘Chiral 4-[(2-isopropyl-5-methylcyclohexyl)oxo]-4-oxobutanoic acid reacts with substituted anilines to produce amides 1-6 in high yields. Resulted amides 1-6 were investigated for their antifungal and antibacterial activities. Compounds 2 (96.5%) against Aspergillus fumigatus and 6 (93.7%) against Helminthosporium sativum demonstrated excellent activities. However, compounds 3 (37.6%) against Bacillus subtilis, 4 (33.2%) against Pseudomonas aurignosa, 5 against Klebsiella pneumonia demonstrated excellent growth inhibition potential.
文摘Investigation of the substitution process can provide a better understanding of the superconducting mechanisms in cuprous oxide materials. In this work the effects of substitution Lanthanum (La) for Gadolinium (Gd) on the structure and oxygen content for x = 0.0 - 0.5 in the compound Gd1-xLaxBa2Cu3O7-δ (GLBCO-123 phase) have been investigated. Samples were synthesized by using a wet-mixing method from powders of Gd2O2, La2O2, BaO, CuO, and solution of HNO3. Based on the analysis of XRD data and SEM-EDXA, it confirms that the sample has formed the GLBCO-123 phase, as expected. It has been obtained that the lattice parameters a and c are increased while the parameter b is slightly decreased with increasing content of Lanthanum. The oxygen content slightly decreased and structure of the Gd1-xLaxBa2Cu3O7-δ phase changed from orthorhombic to tetragonal with increasing the content of Lanthanum.
基金This report is part of the fundamental research report with contract No.486 127/UN14.2/PNL.01.03.00/2016.
文摘In an effort to improve the performance of superconductors in the field and high temperatures it is important to study the superconducting mechanism. For this reason, the cation substitution can be conducted. One of the high Tc superconductors Gd1Ba2Cu3O7−δ phase with Sr substitution has been synthesized, i.e. Gd1(Ba2−xSrx)Cu3O7−δ compound. The sample was synthesized by using a solid-state reaction method with a wet mixing, sintered for 12 hours at temperature 900°C. The synthesis results are characterized by using XRD. The results of Match-3 software analysis showed high (higher 85%) Gd1Ba2Cu3O7−δ phase was formed. The Sr substitution causes changes to the structure, i.e. the lattice parameters a, b and c, where the orthorhombicity tends to decrease with increasing Sr content. Refinement results show that based on the oxygen occupancy, the total oxygen content tends to increase.
