Relative Bioavailability of DL and L-Methionine in Broilers

Studies on the relative bioavailability (RBV) of DL-Methionine (DL-Met) to L-Methionine (L-Met) have produced variable results. An experiment was conducted to determine the RBV of DL to L-Met. A total of 2268 1-day old male chicken were housed in 54 floor pens (42 bird/pen). There were 9 treatments (6 repetitions) including the basal diet (BD). The BD was deficient in Met content with 0.27, 0.26 and 0.25 in the starter, grower and finisher periods respectively. Four levels of experimental diets for each DL-Met and L-Met were created by supplementing 0.05%, 0.10%, 0.15% and 0.20% of DL- or L-Met to the BD. The feeding program consisted of starter (0-14 d, 21% CP and 2900 kcal ME/kg), grower (15 - 28 d, 20% CP and 3000 kcal ME/kg) and finisher period (29 - 37 d, 18.5% CP and 3050 kcal ME/kg). Chickens and feed were weighed at the end of each age period. Regression coefficients of a common plateau asymptotic regression were used to calculate RBV. Birds responded to gradual increase in Met levels, BW, FCR and ADG were significantly (P 0.05) higher in treatment groups as compared to control. Through the study period (37 d), the RBVs of DL-Met for BW and FCR were 89 and 77 respectively.

PURIFICATION OF L-METHIONINE AND N-ACETYL-D-METHIONINE FROM THE MIXTURE OF ENZYMATICALLY DEACYLATED N-ACETYL-DL-METHIONINE

N-acetyl-D-methionine, NaAc and the remains of N-acetyl-L-methionine dramatically affect the purification of L-methionine when purified from the mixture of enzymatically deacylated N-acetyl-DL-methionine, leading to a low yield conventionally. Here, this paper reports a successful separation and purification of both L-methionine and N-acetyl-D-methionine by an H ion-exchange column. The pH, L-Met concentration and the ratio between the content of sodium cation and the ion-exchange capacity were optimized to obtain the maximum yield. Experimental results indicate that, under the optimized conditions, the yields of L-methionine and N-acetyl-D-methionine can reach as high as 85% and 75%, respectively.

A Facile Synthetic Route to L-Phosphinothricin

A convenient and effective method for synthesis of L-phosphinothricin was described. The highlight was involved in a simple access to the key intermediate L-2-amino-4-chlorobutyric acid derivative from the inexpensive L-methionine.

Amelioration of hepatotoxicity by biocleavable aminothiol chimeras of isoniazid: Design, synthesis, kinetics and pharmacological evaluation

AIM To overcome the hazardous effects on liver caused by long-term use of antitubercular agent isoniazid(INH) by developing a novel hepatoprotective prodrug strategy by conjugating INH with aminothiols as antioxidant promoities for probable synergistic effect.METHODS INH was conjugated with N-acetyl cysteine(NAC) and N-(2)-mercaptopropionyl glycine using the SchottenBaumann reaction and with L-methionine using Boc-anhydride through a biocleavable amide linkage. Synthesized prodrugs were characterized by spectral analysis, and in vitro and in vivo release studies were carried out using HPLC. Their hepatoprotective potential was evaluated in male Wistar rats by performing liver function tests, measuring markers of oxidative stress and carrying out histopathology studies.RESULTS Prodrugs were found to be stable in acidic(pH 1.2) and basic(pH 7.4) buffers and in rat stomach homogenates, whereas they were hydrolysed significantly(59.43%-94.93%) in intestinal homogenates over a period of 6 h. Upon oral administration of prodrug NI to rats, 52.4%-61.3% INH and 47.4%-56.8% of NAC were recovered in blood in 8-10 h. Urine and faeces samples pooled over a period of 24 h exhibited 1.3%-2.5% and 0.94%-0.9% of NAC, respectively, without any presence of intact NI or INH. Prodrugs were biologically evaluated for hepatoprotective activity. All the prodrugs were effective in abating oxidative stress and re-establishing the normal hepatic physiology. The effect of prodrug of INH with NAC in restoring the levels of the enzymes superoxide dismutase and glutathione peroxidase and abrogating liver damage was noteworthy especially. CONCLUSION The findings of this investigation demonstrated that the reported prodrugs can add safety and efficacy to future clinical protocols of tuberculosis treatment.

The Role of Abnormalities Related to the One Carbon Cycle in Depression and Schizophrenia

This paper reviews our present knowledge of the role of the one-carbon cycle in mood disorder and schizophrenia with particular attention to S-adenosyl methionine (SAM). After an historical introduction the clinical data is first reviewed of the anti-depressant action of SAM, in particular a survey of double blind placebo-controlled trials. Then follows an account of the biochemical parameters of the action of SAM, in particular the role of folic acid and 5-methyltetrahydrofolate (vitamin B9), polyamines, homocysteine, together with epigenetic studies. In schizophrenia the effect of oral l-methionine on worsening the symptoms of some chronic schizophrenics has been known since 1961. Recent epigenetic research covered has addressed the mechanism of this reaction. This includes the role of SAM in modulating DNA methyltransferase-1 mRNA activity, cytosine 5-methylation, spine numbers and the expression of mRNAs encoding for reelin and GAD67 in GABAergic neurons in the frontal cortex in schizophrenia. There is also evidence that marker D8S542 located within the methionine sulfoxide reductase (MSRA) gene may be involved in schizophrenia as well as 677C > T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene. The possible roles of homocysteine and methionine S-adenosyl transferase kinetics are also discussed.

Catalytic Activity of Amino Acids-Metal Complexes in Oxidation Reactions

Studies were carried out to determine the activity of complexes of the essential amino acids DL-Lysine and L-Methionine with heavy metals in the oxidation of cyclohexene with tert-butylhydroperoxide in toluene at 80°C. All complexes were prepared through interaction of metal ions and DL-Lysine and L-Methionine at room temperature in aqueous solutions. Only the complexes of Mo and W were obtained from acidic aqueous solution. These complexes were characterized by FT-IR, Moessbauer spectroscopy and EPR analysis. The products of the oxidation reactions were identified by GC/MS analysis. The complexes of Mo and V showed the best activity in the epoxidation reaction of cyclohexene in comparison with other complexes, such as Ni, Mn, Zn, Co, Cu, Cr, Fe and W. Using semi-empirical quantum-chemistry methods, the full energy of the Mo complexes was calculated and their probable structure is presented.

Methionine sources and genotype affect embryonic intestinal development,antioxidants,tight junctions,and growth-related gene expression in chickens

Methionine(Met)is an essential and first limiting amino acid in the poultry diet that plays a significant role in chicken embryonic development and growth.The present study examined the effect of in ovo injection of DL-Met and L-Met sources and genotypes on chicken embryonic-intestinal development and health.Fertilized eggs of the two genotypes,TETRA-SL layer hybrid(TSL)—commercial layer hybrid and Hungarian Partridge colored hen breed(HPC)—a native genotype,were randomly distributed into four treatments for each genotype.The treatment groups include the following:1)control non-injected eggs(NoIn);2)saline-injected(SaIn);3)DL-Met injected(DLM);and 4)L-Met injected(LM).The in ovo injection was carried out on 17.5 d of embryonic development;after hatching,eight chicks per group were sacrificed,and the jejunum was extracted for analysis.The results showed that both DLM and LM groups had enhanced intestinal development as evidenced by increased villus width,villus height,and villus area(P<0.05)compared to the control.The DLM group had significantly reduced crypt depth,glutathione(GSH)content,glutathione S-transferase 3 alpha(GST3),occludin(OCLN)gene expression and increased villus height to crypt depth ratio in the TSL genotype than the LM group(P<0.05).The HPC genotype has overexpressed insulin-like growth factor 1(IGF1)gene,tricellulin(MD2),occludin(OCLN),superoxide dismutase 1(SOD1),and GST3 genes than the TSL genotype(P<0.05).In conclusion,these findings showed that in ovo injection of Met enhanced intestinal development,and function,with genotypes responding differently under normal conditions.Genotypes also influenced the expression of intestinal antioxidants,tight junction,and growth-related genes.

A Novel Cu(II) Complex with 2,2′-Bipyridyl and L-Methioninate──Synthesis, Characterization, Molecular Structure and Stability

The ternary Cu(II) complex with 2,2′-bipyridyl (bipy) and L-methioninate (L-Met) has been synthesized and characterized by elemental analysis, molar conductivity, UV-Vis spectra, IR spectra and pH-potentiometric titration methods. The structure of the complex [Cu(L-Met)(bipy)(H_2O)]ClO_4·3/8H_2O was characterized by the X-ray diffraction analysis. It crystallizes in the triclinic system, space group P1 with four molecules in a unit cell of dimensions, a=0.7656(2) nm, b=1.3142(3) nm, c=2.0596(4) nm, α=97.70(3)°, β=97.96(3)°, γ=94.33(3)°, V=2.0244(8) nm 3, R_1=0.0441 and wR_2=0.0678. The crystal contains four crystallographically independent [Cu(L-Met)(bipy)(H_2O)] + complexes (Cu1-Cu4), having a distorted square-pyramidal geometry with the same coordinated atoms around each copper center. The base plane is occupied by two nitrogen atoms of one bipy, the amino nitrogen atom and one carboxylate oxygen atom from each independent L-Met moiety, and one water oxygen at an axial position. Cu1 and Cu3 are essentially enantiomers of Cu2 and Cu4. The four molecules are packed with each other by intermolecular hydrogen-bonding and aromatic-ring stacking interactions.

The in ovo injection of methionine improves intestinal cell proliferation and differentiation in chick embryos by activating the JAK2/STAT3 signaling pathway

The intestinal health of chick embryos is vital for their life-long growth,and exogenous nutrition intervention may provide sufficient nutrition for embryonic development.In the present study,we investigated the effect of in ovo injection of L-methionine(L-Met)on the intestinal structure and barrier function of chick embryos.There were 4 groups of treatments:the control(CON)group injected with phosphate-buffered saline(PBS)and the other 3 groups injected with 5,10,and 20 mg L-Met/egg,respectively.The injection was performed on embryonic day 9(E9),and intestinal samples were collected on the day of hatching for analysis.The results showed that,compared with the CON group,the groups administered an in ovo injection of L-Met increased relative weights of the duodenum,jejunum,and ileum(P<0.05).Hematoxylin and eosin(H&E)staining showed that the groups injected with 5,10,and 20 mg L-Met significantly increased villus height and crypt depth(P<0.05).Moreover,in ovo injection of 10 mg L-Met also increased the transepithelial electrical resistance(TEER)of the jejunum(P<0.05).Injection with 10 and 20 mg L-Met increased the expression of the tight junction proteins(ZO-1 and claudin-1)and the fluorescence signal intensity of Ki67 and villin proteins(P<0.05).Further,the protein expression of phospho-Janus kinase 2(p-JAK2)and phospho-signal transducer and activator of transcription 3(p-STAT3)was significantly increased by 10 or 20 mg L-Met injection(P<0.05).In conclusion,the injection of L-Met,especially at a dose of 10 mg,showed beneficial effects on the intestinal integrity of chick embryos due to the activation of the JAK2/STAT3 signaling pathway.Our results may provide new insights for regulating the intestinal development of embryonic chicks and the rapid growth of chicks after hatching.

Coordination behavior between zinc salts and L-α-methionine

The solubility properties of ZnCl\-2/ZnAc\-2/ZnSO\-4MetH\-2O systems at 25℃ in the whole cocentration range have been investigated by phase equilibrium method. The results indicate that ZnAc\-2 and ZnSO\-4 systems are both simple systems, which do not exist any compound; there are 2 complexes formed in ZnCl\-2 system: Zn（Met）Cl\-2 and Zn（Met）\-2Cl\-2·2H\-2O. Under the direction of phase equilibrium result, 2 solid complexes have been prepared in water and characterized by chemical analysis, IR, Xray diffraction. Their combustion energies have also been determined by means of a RBCtype1 rotatingbomb calorimeter, and their standard enthalpies of formation, Δ f, coor（s）H O-, have been calculated which are （-828.32±3.00） kJ·mol -1 and （-1 117.08±6.15） kJ·mol -1, respectively.