Syntheses and crystal structures of rare earth (Nd, Gd) 1-D chain com-plexes with N-p-tolylsulfonyl-β-alanine

Two rare earth complexes of Ts-β-AlaH with the formula of [Ln2（H2O）4（Ts-β-AlaH）6]n·4nH2O （where Ln = Nd（1）, Gd（2）; Ts-β-AlaH = N-p-tolylsulfonyl-β-Alanine） have been synthesized and characterized by elemental analysis, IR and X-ray diffraction. The results show that the two complexes are isostructural. They crystallize in a monoclinic system with P21/n space group. Crystal data for 1： a = 0.95149（19） nm, b = 1.9012（4） nm, c = 2.2863（5） nm, β= 100.37（3）°, Z= 4, De= 1.509 mg/cm^3, F（000） = 1880, R1= 0.0560, wR2= 0.1564 [I 〉 2σ（/）]; for 2： a = 0.9495（2） nm, b = 1.9037（4） nm, c = 2.2987（5） nm, β= 99.87（3）°, Z = 4, Dc= 1.541 mg/cm^3, F（000） = 1916, R1= 0.0515, wR2= 0.1566 [I〉2σ（I）]. The two complexes are one-dimensional chains and the coordination number of the Nd^3＋ or Gd^3＋ ion is nine.

Beta-alanine promotes angiogenesis in laser-induced choroidal neovascularization mice models

AIM:To investigate the effect ofβ-alanine(BA)on laserinduced choroidal neovascularization(CNV)mice models.METHODS:Laser-induced CNV mice models were established,and BA was administrated for one week and two weeks in advance,separately.Furthermore,retinal pigment epithelium(RPE)-choroid flat mounts were separated,and immunohistochemical staining was performed.The laser-induced CNV lesion areas were measured and compared.In addition,liver and kidney morphologies were observed to identify potential hepatorenal toxicity.RESULTS:Enlarged CNV lesion areas were observed in the BA treated group.No significant differences were observed in the liver and kidney sections between groups.CONCLUSION:BA treatment increase CNV lesion areas,suggesting the detrimental effects of BA as a nutritional supplement in age-related macular degeneration(AMD)population.

Synthesis and Structure of a Novel Tetranuclear Erbium( Ⅲ) Complex with α-Alanine[Er_4(HAla)_6·(μ_3-OH)_4(H_2O)_8](ClO_4)_8·3H_2O

The title complex was synthesized in an aqueous solution and its crystal structure was determined by Xray diffraction. The crystal crystallizes in a triclinic system, space group P1 with a= 1.306 3(2) nm , b=1.319 4(4) nm, c=1.950 2(4) nm, α=90.597(14)°, β= 93.998(11)° , γ=94.093(13)°, V=3.344 1(12) nm3, Z=2, the final R indices are R 1= 0.065 4 , wR 2=0.126 2 respectively. The complex contains a novel tetranuclear cluster cation with four Er 3+ ions connected by four μ 3OH ions and six bridging carboxyl groups. Each erbium ion is coordinated by three μ 3OH, three carboxylic oxygen atoms from three αalanine and two oxygen atoms from water molecules, forming a squareantiprismatic coordination polyhedron.

Bulk Growth and Characterization of D-(–)-Alanine Single Crystals

Single crystal of D-(–)-alanine (DALA), a non-linear optical material from the amino acid family was grown using a home-made crystal growth setup. The crystals of DALA were also grown by slow evaporation solution technique (SEST). The grown crystals were characterized by using single crystal X-ray diffraction, high resolution X-ray diffraction (HRXRD) and UV-vis-NIR and CD spectroscopy. Measurements of Vicker’s microhardness, laser damage threshold (LDT) value and second harmonic generation (SHG) efficiency are also reported. Thermal and dielectric studies were also carried out.

Synthesis and Crystal Structure of N-(2-Pyridylmethyl)-L-Alanine) Isothiocyanate Cobalt(III)

The title compound, [N-(2-pyridylmethyl)-(L)-alanine]Co(III) thiocyanate (1) was obtained from the reaction of Co(OOCH3)2·H2O with the tridentate reduced Schiff base ligand, N-(2-pyridylmethyl)-(L)-alanine (L) and NH4SCN and characterized by elemental analysis, IR, UV-visible, TGA and single- crystal X-ray diffraction. Structural and spectroscopic analyses reveal [Co(L)2)]SCN to be monomeric with Cobalt(III) adopting a pseudo-octahedral geometry, coordinating to two reduce Schiff base ligands. In the crystal lattice, the thiocyanate anion forms an intermolecular SCN···HNamine hydrogen bond, while adjacent monomers are linked by intermolecular Ocarboxyl···HNamine···H-bonds to form a supramolecular network. This work is therefore undertaken in an attempt to construct coordination framework structures of varying properties using the mixed-ligand strategy involving reduced Schiff bases and the thiocyanate ion.

水液相环境下α-丙氨酸二价锌配合物的手性转变机理

采用密度泛函理论的M06和MN15方法,结合自洽反应场理论的SMD模型方法,研究了水液相下两性α-丙氨酸二价锌(α-Ala·Zn^(2+))配合物的手性转变反应。主要考察了3个反应通道a、b和c,a通道是α-H以羰基O为桥迁移,b通道是α-H以Zn为桥迁移,c通道是α-H以氨基N为桥迁移。势能面研究表明,c通道的手性转变反应最具优势,决速步自由能垒是140.7 kJ·mol^(-1),来自α-H从α-C向氨基N迁移的过渡态;a通道的手性转变反应是第2优势通道,决速步自由能垒是159.9 kJ·mol^(-1),来自α-H从α-C向羰基O迁移的过渡态;b通道的手性转变反应为劣势通道,决速步自由能垒是194.2 kJ·mol^(-1),来自α-H从α-C向Zn迁移的过渡态。结果表明:水液相环境下的α-Ala·Zn^(2+)可以较好地保持手性特征。

某些钴(Ⅲ)氨基酸络合物的活性炭催化合成

在研究光学活性络合物的手性识别及拆分机理的过程中,需要合成一系列有特征构型的光学活性钻（Ⅲ）络合物,其配体皆为含N、O配位原子的多齿配体。但是按文献方法合成具有光学活性的u-fac-[Co（ida）2]（ida2;亚氨基二乙酸根）、fac-[Co（β-ala）3]（β-ala:β-丙氨酸根）时,均存在着产率低或产物纯度低,反应时间长等问题,为其后续拆分带来不少困难。为此。

Hygroscopicity measurement of sodium carbonate,β-alanine and internally mixed β-alanine/Na2CO3 particles by ATR-FTIR

Water-uptakes of pure sodium carbonate(Na2CO3),pureβ-alanine and internally mixedβ-alanine/Na2CO3 aerosol particles with different mole ratios are first monitored using attenuated total reflectance Fourier transform infrared spectroscopy(ATR-FTIR)technique.For pure Na2CO3 aerosol particles,combining the absorptions at 877 and 1422 cm-1 with abrupt water loss shows the efflorescence relative humidity(ERH)of 62.9%–51.9%.Upon humidifying,solid Na2CO3 firstly absorbs water to from Na2CO3·H2O crystal at 72.0%RH and then deliquesces at 84.5%RH(DRH).As for pureβ-alanine particles,the crystallization takes place in the range of 42.4%–33.2%RH and becomes droplets at^88.2%RH.Whenβ-alanine is mixed with Na2CO3 at various mole ratios,it shows no efflorescence of Na2CO3 whenβ-alanine to Na2CO3 mole ratio(OIR)is 2:1.For 1:1 and 1:2β-alanine/Na2CO3 aerosols,the ERHs of Na2CO3 are 51.8%–42.3%and 57.1%–42.3%,respectively.Whileβ-alanine crystal appears from 62.7%RH for 2:1 and 59.4%RH for both 1:1 and 1:2 particles and lasts to driest state.On hydration,the DRH is 44.7%–75.2%for Na2CO3 with the OIR of 1:1 and 44.7%–69.0%for 1:2 mixture,and those of β-alanine are 74.8% for 2:1 mixture and 68.9%for two others.After the first dehumidification–humidification,all the water contents decrease despite of constituent fraction.And at^92%RH,the remaining water contents are 92%,89%and 82%at^92%RH,corresponding to OIR of 2:1,1:1 and 1:2 mixed system,respectively.

Fatty acid feedstocks enable a highly efficient glyoxylate-TCA cycle for high-yield production of β-alanine

Metabolic engineering to produce tricarboxylic acid(TCA)cycle-derived chemicals is usually associated with problems of low production yield and impaired cellular metabolism.In this work,we found that fatty acid(FA)feedstocks could enable high-yield production of TCA cycle-derived chemicals,while maintaining an efficient and balanced metabolic flux of the glyoxylate-TCA cycle,which is favorable for both product synthesis and cell growth.Here,we designed a novel synthetic pathway for production of β-alanine,an important TCA cycle-derived product,from FAs with a high theortecial yield of 1.391 g/g.By introducing panD,improving aspA,and knocking out iclR,glyoxylate shunt was highly activated in FAs and the yield of β-alanine reached 0.71 g/g from FAs,much higher than from glucose.Blocking the TCA cycle at icd/sucA/fumAC nodes could increase β-alanine yield in a flask cultivation,but severely reduced cell growth and FA utilization during fed-batch processes.Replenishing oxaloacetate by knocking out aspC and recovering fumAC could restore the growth and lead to a titer of 35.57 g/l.After relieving the oxidative stress caused by FA metabolism,β-alanine production could reach 72.05 g/l with a maximum yield of 1.24 g/g,about 86% of the theoretical yield.Our study thus provides a promising strategy for the production of TCA cycle-derived chemicals.

Synthesis and Structure of a Novel Tetranuclear Erbium(Ⅲ) Complex with L-Proline(HPro)[Er_4(HPro)_4(Pro)_2·(μ_3-OH)_4(H_2O)_7](ClO_4)_6·6H_2O

The title complex was synthesized in an aqueous solution and its crystal structure was determined by Xray diffraction. The crystal crystallizes in a triclinic system, space group P1 with a= 1.306 3(2) nm , b=1.319 4(4) nm, c=1.950 2(4) nm, α=90.597(14)°, β= 93.998(11)° , γ=94.093(13)°, V=3.344 1(12) nm3, Z=2, the final R indices are R 1= 0.065 4 , wR 2=0.126 2 respectively. The complex contains a novel tetranuclear cluster cation with four Er 3+ ions connected by four μ 3OH ions and six bridging carboxyl groups. Each erbium ion is coordinated by three μ 3OH, three carboxylic oxygen atoms from three αalanine and two oxygen atoms from water molecules, forming a squareantiprismatic coordination polyhedron.

Pyruvate-Dependent Changes in Neutrophil Amino- and Alpha-Keto Acid Profiles or Immunity: Which Mechanisms Are Involved?

High current findings indicate that a substitution with pyruvate can lead to significant alterations or even improvement in neutrophil immunonutrition. However, it is still unknown which intra-cellular pathways might be involved here. Hence, in this study, we investigated whether preincu-bation with an inhibitor of ·NO-synthase (L-NAME), an ·NO donor (SNAP), an analogue of taurine (beta-alanine), an inhibitor of ornithine-decarboxylase (DFMO) as well as a glutamine-analogue (DON), is able to alter the intragranulocytic metabolic response to pyruvate, here for example studied for neutrophil intracellular amino- and α-keto acid concentrations or important neutrophil immune functions [released myeloperoxidase (MPO), the formation of superoxide anions O2- and hydrogen peroxide (H2O2)]. In summary, the interesting first results presented here showed, that any damage of specific metabolic pathways or mechanisms, which seem directly or indirectly to be involved in relevant pyruvate dependent granulocytic nutrient content or specific cellular tasks, could lead to therapeutically desired, but also to unexpected or even fatal consequences for the affected cells. We therefore continue to believe that pyruvate, irrespective of which exact biochemical mechanisms were involved, in neutrophils may satisfy the substantial metabolic demands for a potent intracellular nutrient.

Producing malonate in Saccharomyces cerevisiae via theβ‑alanine pathway

Malonate is a high-value chemical that can be used to produce value-added compounds.Due to the toxic by-products and low product yield for malonate production through hydrolysis of cyanoacetic acid,microbial production methods have attracted significant attention.Previously,theβ-alanine pathway has been engineered in Escherichia coli for malonate production.In this study,theβ-alanine pathway was constructed in Saccharomyces cerevisiae by introducing the heterologous genes of BcBAPAT and TcPAND to convert l-aspartate to malonic semialdehyde,combining with co-expression genes of AAT2 and UGA2 to improve precursor supply and malonate producing.Through delta sequence-based integration of the two heterologous genes,the engineered strain produced with 7.21 mg/L malonate was screened.Further,replaced the succinic semialdehyde dehydrogenase gene UGA2 with yneI from E.coli which was utilized to produce malonate in previous study,increased the malonate titer to 7.96 mg/L in flask culture.Following optimization,fermentation of the final engineered strain in shake flasks yielded a maximum malonate titer of 12.83 mg/L,and this was increased to 91.53 mg/L during fed-batch fermentation in a 5 L bioreactor which increased by two-fold compared with that of the engineered strain overexpressing UGA2.