Utilizing CO_(2)for bio-succinic acid production is an attractive approach to achieve carbon capture and recycling(CCR)with simultaneous production of a useful platform chemical.Actinobacillus succinogenes and Basfia ...Utilizing CO_(2)for bio-succinic acid production is an attractive approach to achieve carbon capture and recycling(CCR)with simultaneous production of a useful platform chemical.Actinobacillus succinogenes and Basfia succiniciproducens were selected and investigated as microbial catalysts.Firstly,the type and concentration of inorganic carbon concentration and glucose concentration were evaluated.6 g C/L MgCO_(3)and 24 g C/L glucose were found to be the optimal basic operational conditions,with succinic acid production and carbon yield of over 30 g/L and over 40%,respectively.Then,for maximum gaseous CO_(2)fixation,carbonate was replaced with CO_(2)at different ratios.The“less carbonate more CO_(2)”condition of the inorganic carbon source was set as carbonate:CO_(2)=1:9(based on the mass of carbon).This condition presented the highest availability of CO_(2)by well-balanced chemical reaction equilibrium and phase equilibrium,showing the best performance with regarding CO_(2)fixation(about 15 mg C/(L·hr)),with suppressed lactic acid accumulation.According to key enzymes analysis,the ratio of phosphoenolpyruvate carboxykinase to lactic dehydrogenase was enhanced at high ratios of gaseous CO_(2),which could promote glucose conversion through the succinic acid path.To further increase gaseous CO_(2)fixation and succinic acid production and selectivity,stepwise CO_(2)addition was evaluated.50%-65%increase in inorganic carbon utilization was obtained coupled with 20%-30%increase in succinic acid selectivity.This was due to the promotion of the succinic acid branch of the glucose metabolism,while suppressing the pyruvate branch,along with the inhibition on the conversion from glucose to lactic acid.展开更多
Cerebrovascular accident（CVA）or stroke is one of the world＇s leading causes of death and permanent disability.The high social and medical costs associated with this pathology mean there is an urgent need to find ef...Cerebrovascular accident（CVA）or stroke is one of the world＇s leading causes of death and permanent disability.The high social and medical costs associated with this pathology mean there is an urgent need to find effective therapies.Occlusion of the middle cerebral artery（MCAO）,mainly by clots,is the origin of most CVAs in humans.展开更多
An asymmetric hydrogenation of α-oxymethylcinnamic acids was developed by using chiral spiro phosphineoxazoline/iridium complexes as catalysts to prepare β^(2)-hydroxycarboxylic acids with high reactivity(TON up to ...An asymmetric hydrogenation of α-oxymethylcinnamic acids was developed by using chiral spiro phosphineoxazoline/iridium complexes as catalysts to prepare β^(2)-hydroxycarboxylic acids with high reactivity(TON up to 2000)and excellent enantioselectivity(up to 99.5%ee).By using this highly efficient asymmetric hydrogenation as a key step,a concise total synthesis of natural product homoisoflavone(S)-(+)-4 was accomplished.展开更多
目的:探讨糖尿病肾病(DN)状态下三羧酸(TCA)循环中间代谢产物的差异,观察糖尿病肾病细胞模型中的代谢紊乱。方法:体外培养人肾小管上皮细胞(HK-2),分为对照组(Control)、高糖组(High glucose)、棕榈酸组(PA)、棕榈酸复合高糖组(PA high ...目的:探讨糖尿病肾病(DN)状态下三羧酸(TCA)循环中间代谢产物的差异,观察糖尿病肾病细胞模型中的代谢紊乱。方法:体外培养人肾小管上皮细胞(HK-2),分为对照组(Control)、高糖组(High glucose)、棕榈酸组(PA)、棕榈酸复合高糖组(PA high glucose)。线粒体染色法观察造模后的细胞损伤状况,基于气相的代谢组学方法检测细胞模型中出现的代谢差异,并找出相关差异化合物。气相色谱-质谱(GC-MS)定量方法进一步测定差异化合物的绝对浓度。q PCR测定差异化合物相关通路的酶表达。结果:12、24 h内高糖对HK-2细胞的损伤和代谢影响较弱,而棕榈酸在短期内就可以造成肾脏细胞损伤和代谢紊乱,复合因素下的诱导效果更甚。造模细胞内出现的代谢异常中TCA循环占主要部分,其中柠檬酸和琥珀酸水平出现异常升高。并且琥珀酸水平异常主要由其合成酶影响导致。结论:棕榈酸诱导引起细胞中TCA循环代谢异常变化可能与DN相关。展开更多
The homogeneous and controllable morphology of anhydrous magnesium carbonate(MgCO_(3))particles with excellent properties is difficult to obtain because of a variety of synthetic factors.The effect of succinic acid as...The homogeneous and controllable morphology of anhydrous magnesium carbonate(MgCO_(3))particles with excellent properties is difficult to obtain because of a variety of synthetic factors.The effect of succinic acid as a crystal modifier on the particle morphology transformation of anhydrous MgCO_(3)was investigated by the hydrothermal method.The effect of the addition of succinic acid on the particles was similar to that of temperature change.The morphology of particles with a folded diamond-like shape was gradually uniform,and the particle size was between 3.3 and 7.5μm.Anhydrous MgCO_(3)particles prepared at pH 9 could easily agglomerate,and the average particle size increased from diamond-like to cube-like as the reaction time increased.The interaction between succinic acid and magnesium ions at different concentrations was the main factor responsible for the morphological changes.The pH,temperature,and time affected the molecular motion rate and crystal growth.展开更多
基金supported by the Beijing Nova Program(No.Z201100006820022)the National Natural Science Foundation of China(Nos.52100023,U20B2022)+2 种基金the China Postdoctoral Science Foundation(No.2020M680314)the Key Science and Technology Development Program of Xinjiang Corps(No.2021DB006)the EU ACT Coo CE ERA-NET program cofunded with EUDP-2021-Ⅱ(No.64021-2006)。
文摘Utilizing CO_(2)for bio-succinic acid production is an attractive approach to achieve carbon capture and recycling(CCR)with simultaneous production of a useful platform chemical.Actinobacillus succinogenes and Basfia succiniciproducens were selected and investigated as microbial catalysts.Firstly,the type and concentration of inorganic carbon concentration and glucose concentration were evaluated.6 g C/L MgCO_(3)and 24 g C/L glucose were found to be the optimal basic operational conditions,with succinic acid production and carbon yield of over 30 g/L and over 40%,respectively.Then,for maximum gaseous CO_(2)fixation,carbonate was replaced with CO_(2)at different ratios.The“less carbonate more CO_(2)”condition of the inorganic carbon source was set as carbonate:CO_(2)=1:9(based on the mass of carbon).This condition presented the highest availability of CO_(2)by well-balanced chemical reaction equilibrium and phase equilibrium,showing the best performance with regarding CO_(2)fixation(about 15 mg C/(L·hr)),with suppressed lactic acid accumulation.According to key enzymes analysis,the ratio of phosphoenolpyruvate carboxykinase to lactic dehydrogenase was enhanced at high ratios of gaseous CO_(2),which could promote glucose conversion through the succinic acid path.To further increase gaseous CO_(2)fixation and succinic acid production and selectivity,stepwise CO_(2)addition was evaluated.50%-65%increase in inorganic carbon utilization was obtained coupled with 20%-30%increase in succinic acid selectivity.This was due to the promotion of the succinic acid branch of the glucose metabolism,while suppressing the pyruvate branch,along with the inhibition on the conversion from glucose to lactic acid.
文摘Cerebrovascular accident（CVA）or stroke is one of the world＇s leading causes of death and permanent disability.The high social and medical costs associated with this pathology mean there is an urgent need to find effective therapies.Occlusion of the middle cerebral artery（MCAO）,mainly by clots,is the origin of most CVAs in humans.
基金the National Natural Science Foundation of China,the National Basic Research Program of China(No.2012CB821600)the“111”Project(No.B06005)of the Ministry of Education of China for financial support.
文摘An asymmetric hydrogenation of α-oxymethylcinnamic acids was developed by using chiral spiro phosphineoxazoline/iridium complexes as catalysts to prepare β^(2)-hydroxycarboxylic acids with high reactivity(TON up to 2000)and excellent enantioselectivity(up to 99.5%ee).By using this highly efficient asymmetric hydrogenation as a key step,a concise total synthesis of natural product homoisoflavone(S)-(+)-4 was accomplished.
基金the National Natural Science Foundation of China(grant No.U22A20434)the Foundation from Qinghai Science and Technology Department(grant No.2022-ZJ-706).
文摘The homogeneous and controllable morphology of anhydrous magnesium carbonate(MgCO_(3))particles with excellent properties is difficult to obtain because of a variety of synthetic factors.The effect of succinic acid as a crystal modifier on the particle morphology transformation of anhydrous MgCO_(3)was investigated by the hydrothermal method.The effect of the addition of succinic acid on the particles was similar to that of temperature change.The morphology of particles with a folded diamond-like shape was gradually uniform,and the particle size was between 3.3 and 7.5μm.Anhydrous MgCO_(3)particles prepared at pH 9 could easily agglomerate,and the average particle size increased from diamond-like to cube-like as the reaction time increased.The interaction between succinic acid and magnesium ions at different concentrations was the main factor responsible for the morphological changes.The pH,temperature,and time affected the molecular motion rate and crystal growth.
