Automatic Amino Acid Analyzer Research Articles

Free amino acid content in breast milk of adolescent and adult mothers in Ecuador

Because of increased incidence of teenage births and high prevalence of lactation in Latin America, we determined the patterning of free amino acids (FAAs) in breast milk of 65 primiparous Ecuadorian women of varying ages (14–27 years). An automatic amino acid analyzer quantified levels of FAAs in milk samples obtained at three lactation stages: colostrum, transition, and mature milk. Regardless of mother’s age, most FAAs increased with time postpartum, with taurine, glutamic acid, glutamine, and alanine being most abundant in all stages.

Free amino acids and sugars in the flower of Carthamus tinctorius L.

Qualitative and quantitative analyses of free amino acids and sugars in the extracts from freshly collected florets of <em>Carthamus tinctorius</em> L. were performed by combination of thin-layer chromatography (TLC), automatic amino acid analysis and gas-liquid chromatography (GLC). Sixteen amino acids were detected and their quantitative relations were investigated. Alditol acetate derivatives of free sugars were examined by GLC. The retention time and resolution pattern of the following monosaccharides, rhamnose, arabinose, xylose, mannose and glucose, were ultimately investigated.

Physicochemical property and structural characteristics of glycoprotein from Camellia oleifera Abel seed cake

The glycoprotein was extracted from defatted cake of Camellia oleifera Abel and purified by column chromatography. Physicochemical property and structural characteristics of the glycoprotein were investigated by color qualitative reaction, isoelectric point (PI) test, SDS-PAGE, β-elimination reaction, fourier transform infrared (FTIR) spectroscopy and automatic amino acid analyzer. The results showed that the glycoprotein was a kind of acidic polysaccharide, its relative molecular weight was 2436ku and PI value was 3.6. The type of glycopeptide bond oligosaccharide was O-linkage, and glycosidic bond was pyranose α-glycoside linkage type. The glycoprotein by IR analysis showed the typical absorption of polysaccharide and the presence of was indicated. The glycoprotein determined by automatic amino acid analyzer showed the glycoprotein also contained all human essential amino acids and the proportion was appropriate, which was of great value to develop. The physicochemical property and structural characteristics of glycoprotein from Camellia oleifera Abel seed cake was investigated in this paper, which provided theory basis for further research.

Plasma and tissue free amino acid profiles and their concentration correlation in patients with lung cancer.

Variation of plasma free amino acids (PFAAs) is an essential feature of protein metabolic abnormalities in cancer patients. But there still little data about the cancer tissue free amino acid (TFAAs) profiles, including their patterns and correlations with PFAAs. To evaluate the variation in PFAAs and cancer TFAAs in patients with lung cancer, including their patterns and correlations, we investigated the concentrations of free amino acids in lung cancer tissues (n=27), paired lung paracarcinomous tissues (n=27) and plasma (n=27) using an automatic amino acid analyzer after pre-treatment. Within the PFAAs, the concentrations of five amino acids (tryptophan, glycine, citrulline, ornithine and proline) were significantly decreased, while that of phenylalanine was markedly increased compared with control subjects. Within the TFAAs, the concentrations of three amino acids (taurine, glutamic acid and glycine) were increased, while the concentrations of two amino acids (lysine and ornithine) were decreased significantly in lung cancer tissues compared with the paracarcinomous tissues. The amino acid patterns in PFAAs and TFAAs had similar trends, but percentage variations were diverse. Additionally, the concentrations of five amino acids (lysine, phenylalanine, threonine, serine, and alanine) in PFAAs correlated with those in lung cancer TFAAs, but no amino acids in PFAAs were correlated with those in lung paracarcinomous TFAAs. Thus, PFAA profiles may reflect the status of cancer tissues, which may provide more information about the metabolic statuses and prognoses of patients with lung cancer.

Argininosuccinate synthetase gene is silenced by CpG methylation in children with phenylketonuria

ObjectivesThe concentration of tyrosine and the ratio of branch-amino acid to the aromatic amino acid in phenylketonuria (PKU) patients are much lower than that of normal people, which reveal that PKU patients have amino acid metabolism disorder. The aim of the present study was to investigate the arginine level in blood, the expression of argininosuccinate synthetase (ASS), the rate-limiting enzyme in arginine synthesis pathway, and the methylation of ASS in patients with PKU. Design and MethodsTwenty-five children with PKU and 65 healthy controls were investigated in this study. Blood concentration of arginine was analyzed by automatic amino acid analyzer. The methylation of ASS gene promoter was evaluated by using methylation-specific polymerase chain reaction (MSP) and bisulfite sequencing PCR (BSP) methods, and the mRNA level of ASS was evaluated by semi-quantitative RT-PCR. ResultsBlood concentration of arginine in PKU patients without dietary control was 0.017±0.009mmol/L while in normal persons was 0.129±0.007mmol/L, which is statistically significant (P<0.001). The promoter of ASS was methylated in PKU (15/15, 100%) but not in normal persons (0/15). The mRNA level of ASS in PKU patients was lower than that of normal people, which was well correlated with its methylation status. ConclusionsThe silencing of ASS due to aberrant promoter CpG methylation may be an important mechanism for arginine biosynthesis disorders in PKU. High levels of phenylalanine and low levels of arginine are common characteristics in PKU patients. These findings would extend the current understanding of arginine, ASS in the development of PKU disease.

Analysis of the chemical components of hydatid fluid from Echinococcus granulosus

The aim of this study was to explore the environment of Echinococcus granulosus (E. granulosus) protoscolices and their relationship with their host. Proteins from the hydatid-cyst fluid (HCF) from E. granulosus were identified by proteomics. An inductively coupled plasma atomic emission spectrometer (ICP-AES) was used to determine the elements, an automatic biochemical analyzer was used to detect the types and levels of biochemical indices, and an automatic amino acid analyzer was used to detect the types and levels of amino acids in the E. granulosus HCF. I) Approximately 30 protein spots and 21 peptide mass fingerprints (PMF) were acquired in the two-dimensional gel electrophoresis (2-DE) pattern of hydatid fluid; II) We detected 10 chemical elements in the cyst fluid, including sodium, potassium, calcium, magnesium, copper, and zinc; III) We measured 19 biochemical metabolites in the cyst fluid, and the amount of most of these metabolites was lower than that in normal human serum; IV) We detected 17 free amino acids and measured some of these, including alanine, glycine, and valine. We identified and measured many chemical components of the cyst fluid, providing a theoretical basis for developing new drugs to prevent and treat hydatid disease by inhibiting or blocking nutrition, metabolism, and other functions of the pathogen.

Method validation of 16 types of structural amino acids using an automated amino acid analyzer

An analytical method for the simultaneous determination of 16 types of structural amino acids in infant formula using an automated amino acid analyzer was validated through tests of precision, accuracy and linearity. The automated analysis of the amino acids was performed on an ion-exchange packed column with a visible detector. The certificated reference material (CRM) 1546 from NIST was used as the test sample to determine the precision and accuracy of the analytical method. The regression analyses revealed good correlations [correlation coefficient (r2)] that were greater than 0.99. The recovery values of the amino acids were ranged from 87.18 to 118.08%. The limits of detection and limits of quantification were less than 0.059 mg/100 g and less than 0.198 mg/100 g, respectively. The intra- and inter-day precisions were less than 14.62% in the CRM sample.

Comparative Analysis of Free Amino Acids in &lt;i&gt;Parapenaeopsis hardwickii&lt;/i&gt;, &lt;i&gt;Penaeus vannamei&lt;/i&gt; and &lt;i&gt;Macrobrachium nipponensis&lt;/i&gt;

The contents of free amino acids(FAAs) in Parapenaeopsis hardwickii, Penaeus vannamei and Macrobrachium nipponensis was analyzed by using the automatic amino acid analyzer in this study. The results show that the sequence from the highest to the lowest in total amount of FAAs is Parapenaeopsis hardwickii, Penaeus vannamei and Macrobrachium nipponensis. SPSS(19.0) results indicate that except for Cys, Lys and Thr, FAAs in these three shrimps are significant different (p&lt;0.05), and all of them have a high concentration of Arg, Gly and Pro and a low concentration of Asp and Cys. The content of Gly in shrimp is higher than that of crab and oyster. Both Arg and Gly significantly contribute to the taste of the three shrimps, Glu and Pro play an important role in the flavor of Parapenaeopsis hardwickii and Penaeus vannamei, while not as significant as in the taste of Macrobrachium nipponensis. Composition modes of FAAs which make major contributions to flavor in marine shrimps, Parapenaeopsis hardwickii and Penaeus vannamei, are similar, but different from freshwater shrimp, Macrobrachium nipponensis.

Identification of Different Varieties of Oyster Juice Based on the Comparison of Free Amino Acids

To identify different varieties of oyster juice, a study was conducted to compare the free amino acids (FAAs) determined by automatic amino-acid analyzer in Southern oyster juice, Pacific oyster juice and Pearl oyster juice. In 18 amino acids, glutamic acids, glycine, alanine were considered to be the main flavor amino acids in oyster juice according to the method of Taste Activity Value (TAV). Serine, glycine, alanine, arginine, threonine and histidine proved to be the characteristic amino acids in three oyster juice with different Brix degrees. The standard characteristic amino acids content model chart was established, and it was worked as a characteristic index to identify different varieties of oyster juice. According to the result calculated by included angle cosine, the similarity between the characteristic amino acids content model chart of Southern oyster juice and that of a bottle of market oyster juice turned to be 0.9693.

Characterization and bioactivity of polysaccharides obtained from pine cones of Pinus koraiensis by graded ethanol precipitation.

Pinus koraiensis polysaccharides (PKP) were extracted by hot water from P. koraiensis pine cones. Five polysaccharide fractions named PKP-A, PKP-B, PKP-C, PKP-D and PKP-E were successfully separated at final ethanol concentrations of 30%, 50%, 60%, 70% and 80%, respectively. HPLC, FT-IR, GC-MS and automatic amino-acid analysis were applied to investigate their chemical characteristics. Monosaccharide component analysis indicated that the five fractions were all composed of d-ribose, l-rhamnose, l-arabinose, d-xylose, d-mannose, d-glucose and d-galactose, but their molar ratios were quite different. HPLC results revealed that the polysaccharides precipitated by higher concentrations of ethanol solution had lower molecular masses. Moreover, the antioxidant activities of the five fractions were studied on the basis of hydroxyl radical and ABTS radical scavenging tests. The five graded polysaccharide fractions exhibited good inhibitory power, and MTT tests in vitro showed the IC50 of PKP-A and PKP-E were 1,072.5 and 2,070.0 μg·mL−1, respectively. These results demonstrated that the PKP could be a potential source of natural antioxidants or dietary supplements.

Content of amino acids and minerals in selected sorts of legumes

The aim of this study was to determine amino acid composition and mineral content in selected legume samples. All analyses were carried out at the laboratory temperature of 21±2 °C in triplicate. Amino acid composition was determined using the automatic amino acid analyzer AAA 400 with post-column derivatization. To assess the nutritional value of protein, index of essential amino acids (EAAI) was calculated. Minerals were determined using the atomic absorption spectrometer AA 30. All results were statistically evaluated. The highest content of Cys, Glu, Asp, Leu, Lys and Arg was determined in seeds of G. max; only the content of Cys and His was lower than 10 g kg-1. The greatest total content of essential amino acids (EAA) was discovered in soybeans, almost 128 g kg-1. The majority (Na, K, Mg, and Ca), trace (Fe, Zn, and Cr) and toxic elements (Pb, Cd) were determined. Legumes were rich in Mg and Ca-mainly G. max and Ph. vulgaris. The content of Mg was 2.1 g/1000g in soybeans and 1.6 g/1000g in common beans. Also in these two legumes the greatest concentration of toxic Pb was found. Values obtained during the determination of the chemical composition in samples of legumes and buckwheat products can be influenced by many factors, e.g. climatic conditions, location etc.

Analysis of variation of main components during aging process of Shanxi Aged Vinegar

Shanxi aged vinegar (SAV) is the most famous traditional vinegar in northern China. It is produced from several kinds of cereal by spontaneous solid-state fermentation techniques. The distinctive processing techniques such as &lt;em&gt;smoking of the Pei&lt;/em&gt;, aging by &lt;em&gt;insolating in summer &lt;/em&gt;and &lt;em&gt;taking out&lt;/em&gt; &lt;em&gt;ice in winter&lt;/em&gt; formed during the long-term production practice have&lt;em&gt; &lt;/em&gt;been named as the national intangible cultural heritage. Some research reports about the nutritional composition, flavor compounds of SAV have been published, but there is no report on the changes of main components during aging process in SAV. In this study, the volatile flavor compounds, amino acids, organic acids, trace elements and other conventional ingredients in SAV were examined by headspace solid-phase microextraction gas chromatography-mass spectrometry, automatic amino acid analyzer, high performance liquid chromatography, plasma emission spectroscopy and other modern analytical techniques. The results showed that most conventional ingredients (organic acids, free amino acids, carbohydrates) were increased during aging process. There were 20 different amino acids in SAV, the concentration of total amino acids reached 19.73 mgxmL&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; in eight-year-old vinegar. There were 8 different organic acids in SAV, and acetic acid and lactic acid were main organic acids. A total of 58 different flavor compounds were detected in SAV. The results of this study can help us to understand the class and concentration of main components in SAV, and provide data for manufacturers to improve production process and product quality.

Amino acid, Antioxidant and Ion Profiles of &lt;i&gt;Carpolobia lutea&lt;/i&gt; Leaf (Polygalaceae)

Purpose: To evaluate the amino acid, antioxidant and ionic profiles of Carpolobia lutea leaf (Polygalaceae) extract (CLL). Methods: The powdered leaf was macerated and subjected to gradient solvent extraction with nhexane, chloroform, ethyl acetate and ethanol for 72 h to obtain their respective fractions. Amino acid analysis was by cation-exchange chromatography using automated amino acid analyser. Antioxidant potential was obtained by spectrophotometric assay using 2, 2-Diphenyl-1-picrylhydrazyl DPPH while elemental and ionic analyses were carried out by atomic absorption spectrophotometry and potentiometric titration, respectively. Results: Proline, alanine, serine, valine, glycine, glutamate and lysine were found in the ethanol fraction while lysine, phenyl alanine, glycine and serine were present in the ethyl acetate fraction but not in the non-polar fractions, n-hexane and chloroform. The ethyl acetate fraction contained more lysine, phenyl alanine, glycine and serine the other leaf fractions. Minimal radical scavenging activity of all the fractions was recorded. The most abundant cations in the extract were potassium and phosphorus (2.16 ± 0.05 and 1.90 ± 0.06 mg/g, respectively) while the most abundant anion was phosphate with a concentration of 23.23 ± 4.61 mg/g for the aqueous leaf fraction Conclusion: The study shows that CLL fractions contain variety of amino acids which could promote wound healing, as well as major and minor elemental ions which, as essential body electrolytes, are required for various metabolic processes in the body.

Expression of argininosuccinate synthetase in patients with hepatocellular carcinoma

Arginine is a nonessential amino acid for humans and mice because it can be synthesized from citrulline by argininosuccinate synthetase (ASS) and argininosuccinate lyase. Hepatocellular carcinoma (HCC) is believed to be auxotrophic for arginine through the lack of expression of ASS. However, there are also some ASS-positive HCC cells. Therefore, the aim of this article was to study the levels of arginine and the expression of ASS in patients with HCC. Thirty patients with HCC who had undergone HCC surgery were enrolled in the study. Serum arginine levels were determined with an automatic amino acid analyzer. ASS expression was examined by Western blot and immunohistochemistry. Methylation specific polymerase chain reaction and methylation sequencing were performed to detect the methylation of DNA encoding ASS. There was a decrease of arginine in HCC patients compared with that of healthy control. High expression of ASS was found in the adjacent tissues by Western blot and immunohistochemistry. Little ASS expression was found in most HCC tissues, but there were also some HCC tissues that expressed low levels of ASS. Methylation of the DNA encoding ASS was obviously higher in HCC tissues than that in paired adjacent tissues. ASS expression is decreased significantly in HCC tissues. The downregulation of arginine and ASS expression may be a self-defense action of the body against malignant tumors, and the decreased arginine and ASS levels in HCC patients are an advantage for the arginine deiminase treatment.

Evaluation of Amino Acid and Vitamin B2 and E Composition of Genetically Modified Antidwarf Mosaic Maize by Automatic Amino acid Analyzer and HPLC

Evaluation of Amino Acid and Vitamin B2 and E Composition of Genetically Modified Antidwarf Mosaic Maize by Automatic Amino acid Analyzer and HPLC

Amino acid composition, including key derivatives of eccrine sweat: potential biomarkers of certain atopic skin conditions

The free amino acid (AA) composition of eccrine sweat is different from other biological fluids, for reasons which are not properly understood. We undertook the detailed analysis of the AA composition of freshly isolated pure human eccrine sweat, including some of the key derivatives of AA metabolism, to better understand the key biological mechanisms governing its composition. Eccrine sweat was collected from the axillae of 12 healthy subjects immediately upon formation. Free AA analysis was performed using an automatic AA analyser after ninhydrin derivatization. Pyrrolidine-5-carboxylic acid (PCA) and urocanic acid (UCA) levels were determined using GC/MS. The free AA composition of sweat was dominated by the presence of serine accounting for just over one-fifth of the total free AA composition. Glycine was the next most abundant followed by PCA, alanine, citrulline and threonine, respectively. The data obtained indicate that the AA content of sweat bears a remarkable similarity to the AA composition of the epidermal protein profilaggrin. This protein is the key source of free AAs and their derivatives that form a major part of the natural moisturizing factor (NMF) within the stratum corneum (SC) and plays a major role in maintaining the barrier integrity of human skin. As perturbations in the production of NMF can lead to abnormal barrier function and can arise as a consequence of filaggrin genotype, we propose the quantification of AAs in sweat may serve as a non-invasive diagnostic biomarker for certain atopic skin conditions, that is, atopic dermatitis (AD).

Purification and Characterization of a Yam Glycoprotein Isolated by Alkaline Extraction from Yam Tuber

Yam glycoprotein (YGP) is an important source of bioactives for functional foods. To investigate the effects of alkaline extracting method on the features of YGP, A glycoprotein was isolated from yam tubers by using alkaline processing method, and purified by ion-exchange and gel filtration column chromatography. During the SDS-PAGE eletrophoresis, the result shows a band with approximately 30 kDa molecular weight. The YGP consists of protein moiety (62.34%) and carbohydrate moiety (37.51%), respectively. By the automatic amino acid analyzer detecting, it indicated that the YGP consists of 17 kinds of amino acids and contains a high percentage of glutamic acid and aspartic acid. The results of thin-layer chromatography show that oligosaccharides of the YGP contain D-glucose, D-galactose and mannose.

Free amino acid content in infant formulas

PurposeInfant formula is the sole nutrition and food source for many infants. Information on the free amino acid (FAA) content of formulas, particularly those that are protein hydrolysate based, is limited, despite emerging evidence for the role of FAAs in regulating eating behaviour. The purpose of this paper is to measure levels of essential, semi‐essential, and nonessential FAAs in commercially available infant formulas to provide a foundation for future research examining the influence of FAAs on infant development.Design/methodology/approachUsing an automatic amino acid analyzer, we measured the concentrations of FAAs in four types of formula: two cow milk (CMF); three soy protein (SPF); and three protein hydrolysate (PHF), one of which was a partial hydrolysate (pPHF) and two of which were extensive hydrolysate (ePHF).FindingsIt was found that the amount and number of FAAs varied significantly across formula types: for CMF, total FAAs ranged from 523‐864 μmol/L, with taurine being the most prominent; SPF, 1933‐2450, methionine; pPHF, 2329, taurine; and ePHF, 80375‐85445, leucine. ePHF had the highest levels and the most diversified profiles of FAAs.Research limitations/implicationsStriking discrepancies exist for FAA profiles of infant formulas. Comparison of these data to published psychophysical data on the taste qualities of individual FAAs provides insights into the unique flavor profiles of infant formulas. Overall, the data from this study provide a necessary foundation for future research examining the influence of FAAs in formulas on infant growth and development.Originality/valuePublished data on the FAA content of PHF is limited, despite their increased availability and use. This research is the first to report the FAA content of partial and extensive PHF, and to compare these values to CMF and SPF.

Extraction, purification and antitumor activity of a water-soluble polysaccharide from the roots of Polygala tenuifolia

One polysaccharide PTP was isolated and purified from the roots of Polygala tenuifolia. It consisted of galactose, glucose and galactose in the ratio of 3.1:3.7:2.5, and a small amount of rhamnose, mannose and xylose. 17 general amino acids were identified to be components of the protein-bound polysaccharide analyzed by automatic amino acid analyzer. In order to test the anti-cancer activity of PTP, we investigated its effect against the growth of human ovarian cancer cells SKOV3 in vitro and in ovarian cancer rats. The intracellular reactive oxygen species (ROS) and glutathione (GSH) in SKOV3 cells following PTP treatment were also quantified to explore the possible mechanism underlying the antitumor activity of the polysaccharide. The result showed that PTP is effective on inhibiting the proliferation of SKOV3 cells in a concentration-dependent manner. Furthermore, treatment with PTP caused a rapid depletion of intracellular GSH content and accumulation of intracellular ROS, thus resulting in the apoptosis, which may prove to be a pivotal mechanism for its cancer protection action. In addition, a significant tumor growth inhibition effect was observed in nude mice after PTP administration for 7 weeks. All above indicated PTP could be beneficial towards ovarian cancer therapy.

Expression of N-methyl-d-aspartate receptor 1 and its phosphorylated state in basal ganglia of a neonatal piglet hypoxic-ischemic brain injury model: A controlled study of 1H MRS

Excitatory amino acids (EAAs) and excitotoxicity medicated by receptors of these amino acids play an important role in hypoxic-ischemic brain injury (HIBI), but most studies were ex vivo experiments, the mechanism in vivo is not well understood. We sought to study the expression of N-methyl-d-aspartate receptor 1 (NR1) and phosphorylated N-methyl-d-aspartate receptor 1 (P-NR1) in basal ganglia in a piglet model of HIBI and to investigate the correlation between Glx(Glu/Gln) value measured by magnetic resonance spectroscopy (MRS) and NR1/P-NR1 expression. Multi-voxel 1H MRS was applied to detect change in Glx in basal ganglia of the newborn piglets in vivo. Automatic amino acid analyzer was applied to accurately quantify the Glu concentration. Immunohistochemical method was used to examine the expression of NR1 and P-NR1. The NR1 receptors in basal ganglia of the newborn piglets were significantly activated after HIBI. P-NR1 expression in the basal ganglia was consistent with the change in brain Glu content, so the activation status of NMDA receptor in the brain could be indirectly reflected by β-, γ-Glx/NAA measured by 1H MRS.