• Journal of Food Hygiene and Safety
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• v.35 no.3
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• pp.213-218
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• 2020

This study was conducted to develop a method of analysis for 4-hydroxy-L-isoleucine in the seed extract of fenugreek (Trigonella foenum graecum), a health functional food that contains dietary fiber. The analytical method for 4-hydroxy-L-isoleucine was derived with O-phthaldialdehyde reagent (OPA) and determined by HPLC-PDA. The method was performed on a Capcell Pak C₁₈ UG 120 column (4.6×250 mm, 5 ㎛) in isocratic elution mode using disodium phosphate and acetonitrile. The validation of the developed analytical method was conducted by evaluating several parameters; selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy and repeatability. Excellent linearity (R²=0.999) was observed for 4-hydroxy-L-isoleucine in the concentration range (5-100 ㎍/mL). Observed recoveries of these compounds were found to be between 91.7 and 96.4%. Precision was between 0.2 and 2.4% relative standard deviation (%RSD).

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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• pp.70-76
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• 2001

This experiment was conducted to investigate the effects of crystalline isoleucine supplementation of a low protein, corn-soybean meal diet on the performance and immune function of weanling pigs. Forty-five crossbred ($Duroc{\times}Landrace{\times}Large\;White$) piglets, weighing an average of $11.00{\pm}0.07kg$, were assigned to either a control diet containing 20% crude protein (0.64% isoleucine), a 16% crude protein diet without isoleucine supplementation (0.41% isoleucine) or a 16% crude protein diet supplemented with isoleucine (0.64% isoleucine). Reducing the crude protein content of the diet from 20 to 16% significantly (p<0.05) reduced both average daily gain and feed intake. Feed conversion also tended (p=0.07) to be poorer for a low protein diet without isoleucine supplementation. Isoleucine supplementation of the 16% crude protein diet increased both gain and feed intake to a level similar to that obtained by pigs fed the 20% crude protein diet (p>0.05). Blood urea nitrogen, serum total protein and serum globulin were significantly (p<0.05) higher for pigs fed the unsupplemented 16% crude protein diet than for pigs fed the isoleucine-supplemented diet or the control. Egg albumin antibody titre decreased significantly (p<0.05) in pigs fed the diet with isoleucine supplementation, whereas the antibody titre of pigs fed the low protein and low isoleucine diet was similar to that of pigs fed the diet containing 20% crude protein and 0.64% isoleucine. It was suggested that crystalline isoleucine supplementation of a low protein and low isoleucine diet improved pig performance but suppressed humoral immune function.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.4
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• pp.523-528
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• 2013

This study investigates the effects of three branched-chain amino acids (BCAA; valine, leucine, and isoleucine) on the in vitro ruminal fermentation of wheat straw using batch cultures of mixed ruminal microorganisms. BCAA were added to the buffered ruminal fluid at a concentration of 0, 2, 4, 7, or 10 mmol/L. After 72 h of anaerobic incubation, pH, volatile fatty acids (VFA), and ammonia nitrogen ($NH_3$-N) in the ruminal fluid were determined. Dry matter (DM) and neutral detergent fiber (NDF) degradability were calculated after determining the DM and NDF in the original material and in the residue after incubation. The addition of valine, leucine, or isoleucine increased the total VFA yields ($p{\leq}0.001$). However, the total VFA yields did not increase with the increase of BCAA supplement level. Total branched-chain VFA yields linearly increased as the supplemental amount of BCAA increased (p<0.001). The molar proportions of acetate and propionate decreased, whereas that of butyrate increased with the addition of valine and isoleucine (p<0.05). Moreover, the proportions of propionate and butyrate decreased (p<0.01) with the addition of leucine. Meanwhile, the molar proportions of isobutyrate were increased and linearly decreased (p<0.001) by valine and leucine, respectively. The addition of leucine or isoleucine resulted in a linear (p<0.001) increase in the molar proportions of isovalerate. The degradability of NDF achieved the maximum when valine or isoleucine was added at 2 mmol/L. The results suggest that low concentrations of BCAA (2 mmol/L) allow more efficient regulation of ruminal fermentation in vitro, as indicated by higher VFA yield and NDF degradability. Therefore, the optimum initial dose of BCAA for in vitro ruminal fermentation is 2 mmol/L.

• Journal of Nutrition and Health
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• v.4 no.4
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• pp.39-46
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• 1971

Since ${\beta}-aminoethylphosphonic$ acid was discovered in the living organism, the biosynthesis and biological function of aminophosphonic acids have been extensively studied. The purpose of this project consists in the two parts: 1)the preparation of DL-1-amino-2-phenylethylphosphonic acid (Phenylalanine aminophosphonic acid) and DL-1-amino-3-methylbutyl-phosphonic acid (Isoleucine aminophosphonic acid) by the method of Chamber and Isbell. 2) the study of metabolism and biological functions of those synthetic materials by the animal experiment (white rats) The importance of this project proved to be the first experience fed by animals for the elucidation of biochemical and metabolic functions in the animal body. The following organic synthesis of DL-1-amino-3-methylbutylphosphonic acid and DL-1-amino-2-phenylethylphosphonic acid are studied. 1)Synthesis of DL-1-amino-3-methylbutylphosphonic acid a) Synthesis of Iso-butylbromide b) Synthesis of Ethyl iso-butylmalonate c) Synthesis of Iso-caproic acid d) Synthesis of $Ethyl-{\alpha}-bromo$ iso-caproate e) Synthesis of $Triethyl-{\alpha}-phosphono$ iso-caproate f) Synthesis of DL-1-amino-3-methylbutylphosphonic acid 2)Synthesis of DL-1-amino-2-phenylethylphosphonic acid a) Synthesis of Diethyl phosphite b) Synthesis of Ethylchloro acetate c) Synthesis of Triethyl phospho acetate d) Synthesis of Triethyl benzyl phospho acetate e) Synthesis of DL-1-amino-2-phenylethylphosphonic acid The synthetic compounds; DL-1-amino-3-methylbutylphosphonic acid and DL-1-amino-2-phenyl ethylphosphonic acid which are essential amino acid (isoleucine, phenylalanine)analogue are supplemented to the animal diet at the level of 0.2% and 0.4% for isoleucine analogue and 0.35% and 0.7% for phenylalanine analogue. The plain isoleucine and phenylalanine at the same level in the diet are fercilitated as comparable groups in this study. Two sets of experience including 100 male rats were carried out for seven weeks each total 14 weeks. During this period, urine samples, and each big organs were collected for the analysis of total nitrogen, phosphorus, and glycogen contents in the individual samples by Micro Kjeldahl Fisk & Subbarow and Nelson Somogye, method. 1) The result of the project a) The yield of DL-1-amino-3-methylbutylphosphonic acid and DL-1-amino-2-phenylethylphosphonic acid showed low tendency at the level of 12.5% and 20% Melting point of those two compounds were very high and the ${\alpha}-amino$ group in the synthetic compounds showed positive reaction with ninhydrin in the violet color. b) Ail the experimental groups included in this study revealed statistically no significant difference in the organ weight, total body nitrogen retention and urinary phosphorus excretion This means isoleucine aminophosphonic acid and Phenylalanine aminophosphonic acid were utilized in the body as much as the plain amino acids, isoleucine and phenylalanine did. c) The glycogen contents in the liver of the phenylalaine aminophosphonic acid gruop showed higher statistically significant(p<0.05) in the comparision with the group of the Phenylalanine and the Standard-2. It was noteworthy that the higher glycogen content in the liver might indicate the significance in the incorporation of phenylalanine aminophosphonic acid into the intermediate of tricarboxylic acid cycle as activated state.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.251-261
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• 1987

This study was attempted to increase the production of L-Threonine by Brevibacterium Flavum ATCC 14067, To select the strain which produce the highest threonine, mutants ere induced by N-methyl-N'-nitro-N-nitrosoguanidine treatment. The composition of media and cultural condition for its overproduction of threonine were also studied. In a threonine producer, strain B-13(Met-) was the strain producing the highest amount of threonige among methionine, lysine and isoleucine auxotrophs. The following results were obtained. 1. The wild strain and B-13(Met-) produced threonine 1.4mg/ml and 4.86mg/ml , respectively. 2. The optimum composition of medium for producing threonine by Brevibacterium Flavum B-13 was glucose 10%, ammonium sulfate 4%, potassium phosphate monobasic 0.2%, magnesium sulfate 0.05%, biotin $200{\mu}l$, thiamine $300{\mu}l$. Addition of nicotinic acid also led to increase L-threonine production. 3. In addition of organic nutrients to the fermentation medium, peptone n'ere effective and addition of methionine $100{\mu}g/ml$ produced the highest amount of L-Threonine. Aspartic acid and homoserine were also effective when these amino acid were added to the fermentstion medium. 4. Cultural conditon on threonine production by B-16 were investigated. The optimum pH was 7.0-8.0. The highest amount of threnine was produced after 4 days of cultural period.

• Microbiology and Biotechnology Letters
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• v.19 no.6
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• pp.583-587
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• 1991

A threonine overproducer, E. coli TF427, which is resistant to threonine analogue, a-amino-(3-hydroxyvaleric acid (AHV), and requires both methionine and isoleucine was developed by the mutations of E, coli W3110 using N-methyl-Nf-nitro-N-nitrosoguanidine (NTG) and UV. The E. coli TF427 produced 46.5 gll of threonine in a 5-L jar fermentor after 44 hr cultivation. The aspartokinase I of TF427 was not inhibited by threonine, and its synthesis was not repressed by threonine plus isoleucine.

• Journal of Nutrition and Health
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• v.12 no.1
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• pp.31-41
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• 1979

Free amino acid in ethanol extracts and total amino acids in hydrolysates of eleven species of edible mushrooms were analyzed and determinated the contents five kind of new amino acid by means of amino acid autoanalyzer and gas liquid chromatography. The result obtained from this study are as follows. 1) Five kind of new amino acid turned out to be ${\alpha}$-aminobutyric acid, allo-isoleucine, ethanolamine, $\gamma$-aminobutyric acid and ornithine. 2) By means of amino acid autoanalyzer, the monoethanolamine was identified on the chromatogram ahead of alanine, ${\alpha}$-aminobutyric acid between peak of threonine and glycine, allo-isoeleucine between peak of valine and leucine, isoleucine, ${\gamma}$-aminobutyric acid followed by proline between peak of leucine, isoleucine and methionine and ornithine between peak of phenylalanine and tyrosine 3) By means of Gas liquid chromatography, the ${\alpha}$-aminobutyric acid was identified on the chromatogram between peaks of alanine and valine, allo-isoleucine between peaks of methionine and isoleucine, monoethanolamine followed by ${\gamma}$-aminobutyric acid between peaks of phenylalanine and ammonia, ornithine between the peaks of ammonia and lysine. 4) Of five amino acids which were identified, ornithine was the highest of its content in the mushroom extracts, and allo-isoleucine, ethanolamine, and ${\gamma}$-aminobutyric acid came next in decreasing order. 5) Also which were identified, ornithine was the highest of its content in the hydrolysates, and ${\alpha}$-aminobutyric acid, ${\gamma}$-aminobutyric acid, allo-isoleucine came next in decreasing order, ethanol extracts and hydrolysates of Auriculariaauricula-Judae(Fr.) $Qu\acute{e}l$ species didn't contain any of five kind of new amino acid. Ornithine also was the highest in the hydrolysates of ll mushrooms.

• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.327-330
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• 1996

An amino acid antimetabolite named YS-460 was isolated from the culture filtrate of a newly isolated Actinomycetes identified as Streptomyces sp. Fermentation was carried out in the synthetic medium at 30$\circ$C for 5 days. Purification was done by ion exchange resin, active carbon, silica gel column chromatography and obtained 38 mg of pure active substance per liter of the broth. YS-460, an amino acid like substance, has the molecular formula of C$_{7}$H$_{11}$NO$_{3}$- Its structure determined to be furanomycin by spectral analysis. It is active against some bacteria on a chemically defined medium and reversed competitively by L-isoleucine and non-competitively by L-leucine and L-valine.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.9-17
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• 2018

To investigate the role of bkdR, sigL, yplP, and des genes which were known to be involved in fatty acid synthesis and sensitive at low temperature, deletion mutants of Bacillus subtilis CU1065 and JH642 were constructed. To determine the low temperature sensitivity of these genes, we compared the growth curves of cells at $37^{\circ}C$ and $15^{\circ}C$. At $37^{\circ}C$, wild type and deletion mutants showed almost similar growth but only bkdR deletion strain at $15^{\circ}C$ showed very slow growing compared with wild type. At $15^{\circ}C$ sigL and yplP deletions were somewhat slower or similar to those of wild type strain. Double and triple mutants for bkdR, sigL, yplP deletions were constructed and grown at $20^{\circ}C$ in LB agar to investigate cold sensitive growth. Double or triple deletions including bkdR deletion showed cold sensitive growing. In order to identify more clearly cold sensitive growth, the experiments were carried out under cold shock conditions in which the temperature was lowered from $37^{\circ}C$ to $15^{\circ}C$ at the point of 0.4 optical densities at 600 nm. In these cold shock experiments, only bkdR deletion showed significantly lower growing and additional des deletion increases cold sensitivity. The bkdR activates the bkd operon, which catabolized isoleucine, valine and leucine, amino acids and produce precursors for the synthesis of branched fatty acids. At cold shock growing of bkdR deletion strain, isoleucine recovered cold sensitivity of bkdR deletion but valine did not restore cold sensitivity. Isoleucine is used as a precursor for the synthesis of anteiso-branched fatty acids. On the other hand, valine is used as a precursor for the synthesis of iso-branched fatty acids. This indicates that anteiso-branched fatty acid plays an important role at the cold shock condition.

• Microbiology and Biotechnology Letters
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• v.20 no.1
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• pp.85-90
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• 1992

Rice bran was employed as a main medium component for ethanol fermentation by Saccharomyces species. Among the several strains of .Saccharomyces yeasts. S. cerevisiae IF0 2346 was selected as the hest strain in view of the interest in the production of ethanol and amino acids. It was found that S. cerevisiae IF0 2346 showed $3\times 10^8$cells/d and 4.7% (v/v) ethanol production after 72 hr cultivation. Although total amount of free amino acids was decreased from 1.099 mg/l to 829 mg/l during the fermentation, glutamic acid. histidine, and isoleucine were increased considerably. With the supplement of 5% glucose to the ferrnentation medium, both ethanol and amino acid production were increased up to 134% and 264%, respectively. compared to the control case. Glutamic. acid, leucine, alanine. phenylalanint:, and valine were the major amino acids in the fermentation broth.