单取代苯丙氨基酸卟啉配合物的催化性质研究

初步研究了标题卟啉（Ｈ２Ｐ）及其三种配合物ＭＰ（Ｃｌ）［Ｍ＝Ｆｅ（Ⅲ）、Ｃｏ（Ⅱ）和Ｍｎ（Ⅲ）］存在下，用氧气氧化芳醛的催化吸氧动力学曲线．实验发现除Ｈ２Ｐ外，三种配合物ＭＰ（Ｃｌ）对芳醛的氧化均具有催化作用，其最高吸氧速度按ＭｎＰＣｌ＜ＣｏＰ＜ＦｅＰＣｌ顺序增大，诱导现以ＦｅＰＣｌ＞ＭｎＰＣｌ＞ＣｏＰ顺序减短，还研究了底物、ＭＰ（Ｃｌ）在反应体系中的浓度及溶剂等因素对催化氧化反应的影响．

水杨醛缩氨基酸、联吡啶配合物的电化学合成

以水杨醛缩L-苯丙氨基酸Schiff碱和2,2′-联吡啶为配体的非水溶剂中,用金属Cu、Zn、Ni为"牺牲"阳极,用电化学方法电解合成了Cu(Ⅱ)、Zn(Ⅱ)、Ni(Ⅱ)配合物.讨论了电化学合成的主要影响因素.通过元素分析、红外光谱、紫外光谱、热分析等对配体和配合物进行了表征,确定了配合物的化学组成,同时测定了Ni(Ⅱ)配合物的电化学性质.

苯丙氨酸锂催化醛和胺以及三甲基硅腈三组分的Strecker反应(英文)

以苯丙氨基酸锂为催化剂,成功催化了醛、胺和三甲基硅腈三组分的Strecker反应,并结合一系列氨基酸盐催化剂的筛选以及各种溶剂的选择优化了反应条件.结果表明,利用所述反应可以得到较高收率的α-氨基腈;该三组份的Strecker反应具有反应条件温和、反应收率较高、操作简便、无需繁琐的分离步骤、催化剂便宜且环境友好等优点.

Inhibitory Effect of Ferulic Acid on Oxidation of L-DOPA Catalyzed by Mushroom Tyrosinase

The inhibitory effect of ferulic acid on the diphenolase activity of mushroom tyrosinase and the kinetic behavior were studied with L-3,4-dihydroxyphenylalanine （L-DOPA） as substrate. The inhibitor concentration leading to 50% relative activity lost （IC50） was estimated to be 0.15 mmol·L^-1. The inhibition mechanism obtained from Lineweaver-Burk plots shows that ferulic acid is a competitive inhibitor and the inhibition of tyrosinase by ferulic acid is a reversible reaction. The equilibrium constant for ferulic acid binding with the tyrosinase was determined to be 0.25 mmol·L^-1 for diphenolase. Keywords tyrosinase, ferulic acid, kinetics, inhibition, L-DOPA, diphenolase

Measurement of hepatic functional mass by means of ^(13)C-methacetin and ^(13)C-phenylalanine breath tests in chronic liver disease: Comparison with Child-Pugh score and serum bile acid levels

AIM: To evaluate and compare the clinical usefulness of 13C-phenylalanine and 13C-methacetin breath tests in quantitating functional hepatic mass in patients with chronic liver disease and to further compare these results with those of conventional tests, Child-Pugh score and serum bile acid levels.METHODS: One hundred and forty patients (50 HCV-related chronic hepatitis, 90 liver cirrhosis patients) and 40 matched healthy controls were studied. Both breath test and routine liver test, serum levels of cholic and chenodeoxycholic acid conjugates were evaluated.RESULTS: Methacetin breath test, expressed as 60 min cumulative percent of oxidation, discriminated the hepatic functional capacity not only between controls and liver disease patients, but also between different categories of chronic liver disease patients. Methacetin breath test was correlated with liver function tests and serum bile acids.Furthermore, methacetin breath test, as well as serum bile acids, were highly predictive of Child-Pugh scores. The diagnostic power of phenylalanine breath test was always less than that of methacetin breath test.CONCLUSION: Methacetin breath test represents a safe and accurate diagnostic tool in the evaluation of hepatic functional mass in chronic liver disease patients.

Synthesis and Crystal Structure of O,O-Dimethyl-N-(β-triphenylgermanyl)propionyl-α- aminobenzylphosphonates

The title compound (C30H32NO4PGe), O,O-dimethyl-N-(β-triphenylgermanyl) propionyl-α-aminobenzylphosphonates was synthesized by a convenient method, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is triclinic, space group P-1 with parameters: a=9.7753(5), b=11.5773(5), c=13.5059(6) ?, α=104.185(1),β= 95.971(1), γ =96.727(1)°, V=1457.63(12) ?3, Z=2, Mr=574.13, Dc=1.308 g/cm3, λ=0.71073 ?, μ = 1.139mm-1, and F(000)=596. The structure was solved by direct methods. The structure was refined to R=0.0257, wR=0.0705 for 5080 observed reflections with I >2σ(I).The result of structure analysis indicates that atom Ge is sp3 hydridized because the arrangement of the four carbon atoms bonded to it is a distorted tetrahedron. The geometry of the three phenyl groups linking with the Ge atom looks like a propeller form.

Active changes of lignification-related enzymes in pepper response to Glomus intraradices and/or Phytophthora capsici

The activities of enzymes responsible for lignification in pepper, pre-inoculation with arbuscular mycorrhizal (AM) fungus of Glomus intraradices and/or infection with pathogenic strain of Phytophthora capsici, and the biological control effect of G. intraradices on Phytophthora blight in pepper were investigated. The experiment was carried out with four treatments: (1) plants pre-inoculated with G. intraradices (Gi), (2) plants pre-inoculated with G. intraradices and then infected with P. capsici (Gi+Pc), (3) plants infected with P. capsici (Pc), and (4) plants without any of the two microorganisms (C). Mycorrhizal coloni-zation rate was reduced by about 10% in pathogen challenged plants. Root mortality caused by infection of P. capsici was com-pletely eliminated by pre-inoculation with antagonistic G. intraradices. On the ninth day after pathogen infection, Peroxidase (POD) activity increased by 116.9% in Pc-treated roots but by only 21.2% in Gi+Pc-treated roots, compared with the control, respectively. Polyphenol oxidase (PPO) and Phenylalanine ammonia-lyase (PAL) activities gradually increased during the first 3 d and dramatically decreased in Pc-treated roots but slightly decreased in Gi+Pc-treated roots, respectively. On the ninth day after pathogen infection, PPO and PAL decreased by 62.8% and 73.9% in Pc-treated roots but by only 19.8% and 19.5% in Gi+Pc-treated roots, compared with the control, respectively. Three major POD isozymes (45 000, 53 000 and 114 000) were present in Pc-treated roots, while two major bands (53 000 and 114 000) and one minor band (45 000) were present in spectra of Gi+Pc-treated roots, the 45 000 POD isozyme was significantly suppressed by G. intraradices, suggesting that the 45 000 POD isozyme was induced by the pathogen infection but not induced by the antagonistic G. intraradices. A 60 000 PPO isozyme was induced in Pc-treated roots but not induced in Gi+Pc-treated roots. All these results showed the inoculation of antagonistic G. intraradices alleviates root mortality, activates changes of lignification-related enzymes and induces some of the isozymes in pepper plants infected by P. capsici. The results suggested that G. intraradices is a potentially effective protection agent against P. capsici.

Prognostic value of ^(13)C-phenylalanine breath test on predicting survival in patients with chronic liver failure

AIM: To evaluate the prognostic value of percentage of 13C-phenylalanine oxidation (13C-PheOx) obtained by 13C-phenylalanine breath test (13C-PheBT) on the survival of patients with chronic liver failure. METHODS: The hepatic function was determined by standard liver blood tests and the percentage of 13C-PheOx in 118 chronic liver failure patients. The follow-up period was of 64 mo. Survival analysis was performed by the Kaplan-Meier method and variables that were significant (P < 0.10) in univariate analysis and subsequently introduced in a multivariate analysis according to the hazard model proposed by Cox. RESULTS: Forty-one patients died due to progressive liver failure during the follow-up period. The probability of survival at 12, 24, 36, 48 and 64 mo was 0.88, 0.78, 0.66, 0.57 and 0.19, respectively. Multivariate analysis demonstrated that Child-Pugh classes, age, creatinine and the percentage of 13C-PheOx (HR 0.338, 95% CI: 0.150-0.762, P = 0.009) were independent predictors of survival. When Child-Pugh classes were replaced by all the parameters of the score, only albumin, bilirubin, creatinine, age and the percentage of 13C-PheOx (HR 0.449, 95% CI: 0.206-0.979, P = 0.034) were found to be independent predictors of survival.CONCLUSION: Percentage of 13C-PheOx obtained by 13C-PheBT is a strong predictor of survival in patients with chronic liver disease.

Synthesis of Protected Tetrapeptide, N-o-Ns-N(Me)-Val-N(Me)-Val-N(Me)-Val-N(Me)-Phe-O^tBu

The protected tetrapeptide, N-o-Ns-N （ Me ） -Val-N （ Me ） -Val-N （ Me ） -Val- N （ Me ） -Phe- OtBu, was prepared from L-valine and L-phenylalanine. Ted-butyl acetate and HClO4 were used to protect carbonyl group, o-nitrobenzenesulfonyl chloride and triethyl amine were used to protect amino group, and N-alkylation was finished with iodomethane. Then the protected amino acid was turned into acid chloride which was taken as coupling reagent. After 14 steps, such as protection, alkylation, deprotection and coupling, the protected tetrapeptide was obtained with a yield of 26.9%. The structures of intermediates and target compound were identified with NMR spectra and high resolution mass spectra.

Preparation and enantiosorption of L-aspartic acid pillared hydrotalcites

L-aspartic acid （Asp） pillared hydrotalcites were prepared by direct reaction of the L-Asp anion with layered double hydroxides （LDHs）. The obtained samples were characterized by X-ray diffractometry （XRD）, Fourier transform infrared （FTIR）, and thermogravimetric and differential thermal analysis （TG/DTA）. The results show that the initial interlayer carbonate ions can be completely replaced by the L-Asp anion under the controlled conditions. The pillared hydrotalcites have a crystallized supramolecular structure and thermal stability. The L-Asp pillared LDHs were used in the enantiosorption of enantiopure phenylalanine （Pile）, the results suggest that L-Asp pillared LDHs exhibit an excellent enantiosorption capability for D-Phe, and the adsorption isotherm fits Freundlich equation.

SYNTHESIS AND CATALYTIC PROPERTY OF POLYSTYRENE SUPPORTED PHENYLALANINE SCHIFF BASE COMPLEX OF Mn(Ⅱ) IN AEROBIC OXIDATION OF CYCLOHEXENE

The polystyrene supported phenylalanine Schiff base complex of Mn（Ⅱ） （PS-Sal-Phe-Mn ） was prepared with chloromethylated styrene polymer heads, 2 L-phenylalanine and manganese （Ⅱ） acetate tetrahyrate., The polymeric ligand and the complex were characterized by FT.IR,, small area X-ray photoelectron spectroscopy （XPS）, and ICP-AES. in the presence of the manganese complex, cyclohexene （1） was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2.cyclohexen-l-ol （2）, 2-cyclohexen-l-one （3）and 2-cyclohexen-1-hydroperoxide （4）, which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-l-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.

TWO NOVEL MUTATIONS IN PHENYLALANINE HYDROXYLASE GENE AND IN VITRO EXPRESSION ANALYSIS ON MUTATION ARG252GLN

We report novel mutations in exon 7 of human phenylalanine hydroxylase (PAH) gene of phenylketonuria (PKU ) in southern Chinese, analysed by using PCR-DGGE (denaturing gradient gel electrophoresis ), solid phase DNA sequencing and Ih vliro expression. One of the 2 novel mutations, IVS6nt1, is an intron-exon Junctional mutation which results a splicing defect in mRNA. Arg252Gln is another novel mutation with residual PAH activity only 24 % compared to wild type in in vitro mutagenesis and expression in Cos-1 cell. Other 3 known mutations and polymorphism including Arg241Cys, Arg243Gln and Val245Val(GTG to GTA) together with these novel mutations composed the mutatlonal profile of exon 7 in the PAH gene of PKUs in this populations.

MUTATIONS IDENTIFIED IN EXON 7 OFPHENYLALANINE HYDROXYLASE GENE IN CHINESE

Exon 7 of the l’henylalan1ne hydroxylase (PAH) gene was analyzed in 15 chlldren affected wlth classicphenylketonL1rla (PKU) from northern Chlna by uslng PCRxsingle strand conformation polymorphism(PCR-SSCP) technique and DNA direct sequencing. Six missense mutatlons (l. e. R2413Q. R 241H, G247V,1,2 19H, F2541;lnd G257V )and one silent rnutatlon (V245v ) were identified. The latter three missense mu-tations were demonstrated as novel mltations in comparison with the PAH mutation database. one missense mt1tation (R241 H) was flrst dowumeTlted in Chinese. our results showed populatlon ancl reglon tllffer-ences in the PAH mutation clistribution. and suggest that there is more thfln one founding population forPKU in China. The fincling of novel mutations will enhence the molecular diagnosis of PKU.

Plasma amino acid profiling of cancer patients with abnormal Savda based on high-performance liquid chromatography

OBJECTIVE: To investigate metabolic signatures in plasma of cancer patients with abnormal Savda using plasma-free amino acid profiles, and to evaluate the diagnostic potential of these profiles for the detection and explanation of the mechanisms of different symptoms in traditional Uyghur medicine.METHODS: Plasma samples from cancer patients with abnormal Savda(n=85) or non-abnormal Savda(n=105) and a healthy control group(n=65)were analyzed using high-performance liquid chromatography(HPLC). Orthogonal projection to latent structures with discriminant analysis was used for the classification and prediction of abnormal Savda, and spectral profiles were subjected to Student's t-tests to assess statistical significance.RESULTS: Compared with the healthy group, the levels of aspartic acid, glutamate, glycine, histidine,arginine, threonine, alanine, proline, methionine,isoleucine, leucine and phenylalanine decreased significantly in plasma of cancer patients with abnormal Savda(all P<0.05). Serine, cystine, tyrosine,valine and lysine levels showed no significant differences(all P>0.05). Compared with non-abnormal Savda syndrome patients, abnormal Savda syndrome patients showed high concentrations of glutamate, serine, valine, isoleucine, leucine and phenylalanine(all P<0.05). The remaining plasma amino acids showed no significant differences(all P>0.05).CONCLUSION: Plasma-free amino acid profiling has the potential to assist in understanding and determining abnormal Savda. A HPLC-based metabonomic platform could be a powerful tool for the classification of symptoms in traditional medicine.

Improved synthesis of rupintrivir

An improved synthesis of rupintrivir (AG7088) was accomplished using three amino acids (L-glutamic acid, D-4-fluorophenylalanine, and L-valine) as the building blocks. The key fragment ketomethylene dipeptide isostere was constructed with the valine derivative and phenylpropionic acid derivative, followed by coupling with a lactam derivative and an isoxazole acid chloride to provide AG7088 totally in eight steps.