用活性碳分离纯化苯丙氨酸与酪氨酸的研究

根据活性炭对L-苯丙氨酸与L-酪氨酸的选择性吸附特性，通过活性炭吸附及氨水、乙醇溶液解吸，从啤酒酵母提取液中成功地分离提取了符合标准的L一苯丙氨酸与L-酪氨酸；实验研究了苯丙氨酸与酪氨酸在不同pH值溶液中在活性炭上的吸附平衡，确定了以pH值5．8上柱，1mol氨水和60％乙醇二步洗脱分离提取两种氨基酸的工艺，为从啤酒酵母中提取氨基酸提供了一条有效的途径。     

Development of Polypyrrole Modified Screen-Printed Carbon Electrode Based Sensors for Determination of L-Tyrosine in Pharmaceutical Products

Good health, of vital importance in order to carry out our daily routine, consists of both physical and mental health. Tyrosine (Tyr) deficiency as well as its excess are issues that can affect mental health and can generate disorders such as depression, anxiety, or stress. Tyr is the amino acid (AA) responsible for maintaining good mental health, and for this reason, the present research presents the development of new electrochemical sensors modified with polypyrrole (PPy) doped with different doping agents such as potassium hexacyanoferrate (II) (FeCN), sodium nitroprusside (NP), and sodium dodecyl sulfate (SDS) for a selective and sensitive detection of Tyr. The development of the sensors was carried out by chronoamperometry (CA) and the electrochemical characterization was carried out by cyclic voltammetry (CV). The detection limits (LOD) obtained with each modified sensor were 8.2 × 10⁻⁸ M in the case of PPy /FeCN-SPCE, 4.3 × 10⁻⁷ M in the case of PPy/NP-SPCE, and of 3.51 × 10⁻⁷ M in the case of PPy/SDS-SPCE, thus demonstrating a good sensitivity of these sensors detecting L-Tyr. The validation of sensors was carried out through quantification of L-Tyr from three pharmaceutical products by the standard addition method with recoveries in the range 99.92–103.97%. Thus, the sensors present adequate selectivity and can be used in the pharmaceutical and medical fields.     

三酶偶联全细胞生物合成L-酪氨酸

通过将醛缩酶(ALD)、D-丝氨酸脱水酶(SDH)和酪氨酸酚裂解酶(TPL)三酶偶联,催化甘氨酸、甲醛和苯酚合成L-酪氨酸(L-Tyr)。并以L-Tyr的质量浓度为指标对转化工艺进行了考察。结果表明:三酶偶联最佳反应条件为pH=8.5、温度35℃、乙酸铵质量分数6 g/L、磷酸吡哆醛(PLP)质量浓度0.1 g/L、3种酶细胞配比m(ALD)∶m(SDH)∶m(TPL)=6∶3∶5。当甘氨酸加量为50 g/L,利用上述工艺进行10000 L放大,反应11 h,L-Tyr质量浓度可达117 g/L,苯酚转化率为97%,转化体系放大后苯酚转化率提高4%,收率为85%。     

L-酪氨酸模板仿生合成MnO2及其催化性能的研究

以MnSO4和NaOH为原料,利用L-酪氨酸为模板仿生合成MnO2,SEM表征表明其形貌呈片状,XRD表征表明其为β-MnO2.研究MnO2催化甲基橙氧化降解性能,考察其对H2O2降解甲基橙模拟废水的催化能力,并利用SAS统计软件（SAS Institute Inc.,Cary,NC,USA,Version 8.0）对MnO2添加量、甲基橙溶液初始质量浓度和甲基橙溶液初始pH进行了优化.其优化后的试验结果为甲基橙溶液初始pH为4,甲基橙溶液初始质量浓度为9mg/L,MnO2添加量为0.42g/L.     

过渡金属酪氨酸配合物热化学性质的研究

合成了过渡金属(铜、镍)与L-酪氨酸的固态配合物,通过化学分析、IR及TG-DTA对其组成及热稳定性进行了研究,确定了配合物的组成为Cu(Tyr) (Ac)2·3H2O和Ni(Tyr)Cl2·5H2O。用HWR-15型恒温式微机量热计测定了上述配合物的恒容燃烧能,并计算了它们的标准摩尔燃烧焓(△c Hφm)和标准摩尔生成焓(△f Hφm