• Title/Summary/Keyword: Aromatic amino acid

Search Result 141, Processing Time 0.026 seconds

Assay Method of L-tyrosine and L-DOPA Mixture Using Spectrophotometer (분광광도계를 이용한 L-tyrosine과 L-DOPA 혼합물의 분석방법)

  • 김지현;유영제
    • KSBB Journal
    • /
    • v.5 no.2
    • /
    • pp.191-194
    • /
    • 1990
  • Tyrosine is a monohydrolic aromatic amino acid and DOPA is a tyrosine derivative containing dihydroxy group. DOPA can be synthesized from tyrosine by enzymatic reaction. The separation and quantitative determination of each component are very difficult in the reaction mixture. In the present study, two wavelengths giving maximum absorbance difference of each amino acid were determined using UV/VIS spectrophotometer by wavelength scanning and simple assay method was developed for the analysis of the reaction mixture of tyrosine and DOPA by measuring absorbances of reaction mixture. This method can be simply used for the analysis of the tyrosine and DOPA mixture because it does not require and procedure for the pretreatment of the reaction mixture.

  • PDF

Purification and Partial Amino Acid Sequence of a Bacteriocin Produced by Lactococcus, sp. HY449 (Lactococcus sp. HY449가 생산한 Bacterisocin의 정제)

  • 오세종;이상준;김경태;김상교;박연희;백영진
    • Microbiology and Biotechnology Letters
    • /
    • v.29 no.3
    • /
    • pp.155-161
    • /
    • 2001
  • A bactriocin produced by Lactrococcus sp. HY449 was purified by sequential purfication steps such as n-propanol-acetone precipitation ion -exchange chromatography using CM-Sequential CL6B. gel filtration chromatography using Sephacry HR100 and reverse-phase chromatography using pro RPC HR 5/10. Reverse-phase chromatography the final step of the purfication yielded a single symmetrical peak of bacteriocin activity The purification resulted in final yield of 3.25% and 413.35 fold increase of the specific activity of bacteriocin. The active fraction from reverse-phase chromatography was used for N-terminal amino acid analysis . The purified bacteriocin contained isoleucine, leucine, methionine, and glycine at but N-terminal end no aromatic amino acids. Calculation of the number of amino acid residues in the bacteriocin revealed that it is consisted of 32 residues assuming the molecular weight of bacteriocin to be about 3.6kDa. Edman degrandation elucidated amino acid residues of the first four of the N-terminus to be $NH_2$-Ile-Leu-Pro-GIn.

  • PDF

Studies on Silk Fibroin Membranes(II) -Adsorption of Acid Dyes in Silk Fibroin Memberane- (Silk Fibroin 막에 관한 연구 (II) -Silk Fibroin 막에 대한 산성염료의 흡착-)

  • 최해욱;박수민;김경환
    • Textile Coloration and Finishing
    • /
    • v.6 no.3
    • /
    • pp.60-66
    • /
    • 1994
  • With the view of studying on the dual adsorption mechanism of acid dyes in connection with the structural difference of silk fibroin, silk fiber and silk fibroin memberane were used for equilibrium dyeing at $60^{\circ}C$, $70^{\circ}C$, $80^{\circ}C$ and pH 3.2, pH 5.0. The dyes used were C.I.Acid Orange 7 and C.I.Acid Red 88 introduced aromatic hydrocabon into Acid Orange 7. From the adsorption isotherm experiment, the total uptake of dyes can be described by Langmuir sorption and Nernst partition. Nernst partition. Nernst partition coefficient $K_1$ decrease of crystalline regions and orientation. The saturation value S of Acid Red 88 were large than total amino group contents and it was attributed it hydrophobic bond. On the other hand, the standard afficity and enthalpy were increased with the in crease of hydrophobic part of dyes. Both $k_1$ and $K_2$ were decreased with the increase of pH, but $k_2$ were more effected than $K_1$.

  • PDF

Cloning of the Transketolase Gene from Erythritol-Producing Yeast Candida magnoliae

  • Yoo, Boung-Hyuk;Park, Eun-Hee;Seo, Jin-Ho;Kim, Myoung-Dong
    • Journal of Microbiology and Biotechnology
    • /
    • v.24 no.10
    • /
    • pp.1389-1396
    • /
    • 2014
  • The entire nucleotide sequence of the TKL1 gene encoding transketolase (TKL) in an erythritol-producing yeast of Candida magnoliae was determined by degenerate polymerase chain reaction and genome walking. Sequence analysis revealed an open reading frame of C. magnoliae TKL1 (CmTKL1) that spans 2,088 bp and encodes 696 amino acids, sharing 61.7% amino acid identity to Kluyveromyces lactis TKL. Functional analysis showed that CmTKL1 complemented a Saccharomyces cerevisiae tkl1 tkl2 double mutant for growth in the absence of aromatic amino acids and restored transketolase activity in this mutant. An enzyme activity assay and RT-PCR revealed that the expression of CmTKL1 is induced by fructose, $H_2O_2$, and KCl. The GenBank accession number for C. magnoliae TKL1 is KF751756.

Chemical Composition of Seed from Inbred Lines and Hybrids of Maize Recently Developed in Korea (국내 육성 주요 옥수수 자식계통 및 교잡종의 종실 성분 특성)

  • Son, Beom-Young;Kim, Jung-Tae;Lee, Jin-Seok;Baek, Seong-Bum;Kim, Sun-Lim;Ku, Ja-Hwan;Hwang, Jong-Jin;Cha, Sun-Mi;Kwon, Young-Up
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.57 no.2
    • /
    • pp.188-194
    • /
    • 2012
  • This study was carried out to evaluate the quality properties, fatty acid composition and amino acid composition of major Korean inbred lines and hybrids of maize for corn breeding. Protein content of $F_2$ seeds was 9.0%, which was slightly lower than those of inbred lines, 11.4%, and $F_1$ seeds, 10.9%. in hybrid maizes. Lipid content of $F_2$ seeds of hybrid maizes was 4.2%, slightly higher than those of inbred lines, 3.3%, and $F_1$ seeds, 3.6%. However, there was no significant difference in ash content. The amount of linoleic acid in inbred lines, $F_1$ and $F_2$ seeds of hybrid maizes was highest among all fatty acids and followed by oleic acid, palmitic acid, stearic acid and linolenic acid. The composition of saturated fatty acid of $F_2$ seeds was 17.6%, similar to $F_1$ seeds but it was lower than that of inbred lines. The composition of unsaturated fatty acid of $F_2$ seeds was 82.4%, similar to $F_1$ seeds but was higher than inbred lines. The content of leucine of $F_2$ seeds was lower than inbred lines and $F_1$ seeds. The content of valine, serine, threonine, cysteine, aspartic acid, lysine, arginine, histidine of $F_2$ seeds was higher than inbred lines and $F_1$ seeds. MMA (monoamino monocarboxylic acid) in inbred lines, $F_1$ and $F_2$ seeds of hybrid maizes was highest among all amino acids and followed by DMA (diamino monocarboxylic acid) and AAA (aromatic amino acid).

The Crystal Structure of Tolfenamic Acid $(C_{14}H_{12}ClNO_2)$, an Antiinflammatory Fenamate

  • Kim, Yang-Bae;Chung, Uoo-Tae;Park, Il-Yeong
    • Archives of Pharmacal Research
    • /
    • v.19 no.2
    • /
    • pp.160-162
    • /
    • 1996
  • The structural analysis of tolfenamic acid, 2-[(3-chloro-2-methylphenyl)-amino]benzoic acid, was performed by single crystal X-ray diffraction technique. The compound was recrystallized from a mixture of ether and toluene in triclinic, space group $P2_1/c, \;with\; \partial=3.914(1), \; b=22.\; 020(2), \; c=14.271(1)\;{\AA}, \beta.=94.68(1)^{\circ}, $ and Z=4. The calculated density is $1.418 g/cm^3$. The structure was solved by the direct method and refined by full matrix least-squares procedure to the final R value of 0.039 for 1773 independent reflections. In the molecule, carboxyl group at the anthranilic acid is coplanar to the phenyl ring. The dihedral angle between the two aromatic rings of the molecule is $44.2^{\circ}$ The molecules are dirnerized through the intermolecular hydrogen bonds at the carboxyl group in the crystal.

  • PDF

Physicochemical attributes, oxidative stability, and microbial profile of boneless sirloin and bone-in T-bone steaks from Hanwoo steer with reference to dry-aging

  • Ali, Mahabbat;Nam, Ki-Chang
    • Journal of Animal Science and Technology
    • /
    • v.63 no.5
    • /
    • pp.1169-1181
    • /
    • 2021
  • We investigated the comparative physicochemical attributes, oxidative stability, and microbial characteristics of 28 days dry-aged meat in between boneless sirloin (gluteus medius) and bone-in T-bone steaks (infraspinatus) muscles from Korean Native Hanwoo Steer (KNHS). Results reveal that regardless of the muscles, dry-aging increased protein content and water-holding capacity (WHC) (p < 0.05). Meat from infraspinatus-aged muscle led to darker meat with higher pH values than un-aged meat (p < 0.05). However, fat content, CIE a*, and CIE b* remained unchanged in both muscles at aging. At aged meat, thiobarbituric acid reactive substances (TBARS) values from bone-in infraspinatus muscle was 2.5-fold higher than boneless gluteus medius muscle (p < 0.05). Dry-aging led to an increase in the contents of total unsaturated fatty acids (UFAs), monounsaturated fatty acids (MUFAs), and UFA/saturated fatty acids (SFA) in both muscles (p < 0.05). Furthermore, gluteus medius aged muscle concentrated with olic acid (C18:1) compared to infraspinatus aged muscle. Irrespective of the muscles, dry-aging enhanced the total free amino acids (FAAs) as well as tasty, and bitter amino acid contents whereas decreased the tasty/bitter amino acids (p < 0.05). Aromatic amino acid, tryptophan that converted to serotonin was 2-fold higher in boneless gluteus medius muscle than bone-in infraspinatus muscle at pre and post aging processes (p < 0.05). Aged Infraspinatus muscle increased total bacteria (p < 0.05) while no salmonella spp. was detected in both muscles. Taken together, our study confirms that 28 days dry-aging profiling the quality characteristics of boneless sirloin (gluteus medius) and bone-in T-bone steaks (infraspinatus) distinctly while gluteus medius aged steak performs better owing to oxidative stability and functional compounds than infraspinatus aged steak.

Antioxidant and Antihypertensive Activities of Grains Grown in South Korea in Relation to Phenolic Compound and Amino Acid Contents

  • Narae Han;Koan Sik Woo;Jin Young Lee;Jiho Chu;Mihyang Kim;Yu-Young Lee;Moon Seok Kang;Hyun-Joo Kim
    • The Korean Journal of Food And Nutrition
    • /
    • v.36 no.6
    • /
    • pp.572-580
    • /
    • 2023
  • Hypertension is characterized by excessive renin-angiotensin system activity, leading to blood vessel constriction. Several synthetic compounds have been developed to inhibit renin and angiotensin-converting enzyme (ACE). These drugs often have adverse side effects, driving the exploration of plant protein-derived peptides as alternative or supplementary treatments. This study assessed the phenolic compound and amino acid content and the antioxidant and antihypertensive activity of 5 South Korean staple crops. Sorghum had the highest phenolic compound content and exhibited the highest antioxidant activity. Millet grains, particularly finger millet (38.86%), showed higher antihypertensive activity than red beans (14.42%) and sorghum (17.16%). Finger millet was found to contain a large proportion of branched-chain, aromatic, and sulfur-containing amino acids, which are associated with ACE inhibition. In particular, cysteine content was positively correlated with ACE inhibition in the crops tested (r=0.696, p<0.01). This study confirmed that the amino acid composition was more correlated with the antihypertensive activity of grains than the phenolic compound content. Finger millet mainly contained amino acids, which have higher ACE inhibitory activity, resulting in the strongest antihypertensive activity. These findings underscore the antihypertensive potential of select crops as plant-based food ingredients, offering insight into their biological functions.

Conversion of Brown Materials, Crude Lipids, Crude Proteins and Aromatic Compounds of Changed Ginseng by 9 Repetitive Steaming and Drying Process (인삼의 구증구폭(九蒸九曝)에 의한 갈변물질, 조지방, 조단백 및 향기성분의 변화)

  • Kim, Do-Wan;Lee, Yun-Jin;Min, Jin-Woo;Lee, Bum-Soo;In, Jun-Gyo;Yang, Deok-Chun
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.22 no.2
    • /
    • pp.333-339
    • /
    • 2008
  • Korean ginseng (Panax ginseng C. A. Meyer) has been used as an important medicinal plant in the Orient for a long time. It has been claimed that ginseng has many beneficial bioactive effects on human health, such as antitumor, antistress, antiaging and enhancing immune functions. Red ginseng possibly have new ingredients converted during steaming and dry process from fresh ginseng. Kujeungkupo method which means 9 repetitive steaming and drying process was used for the processes of green tea, Polygonatum odoratum, and Rehmanniae radix preparata. In this study, ingredient conversion of ginseng by 9 repetitive steaming and drying process were investigated measuring conversion efficiency of brown materials, crude lipids, crude proteins and aromatic compounds. Brown materials, as an antioxidant, in red ginseng were produced through non-enzymatic reaction by heat. Repetitive steaming and drying treatments on ginseng root contiunously increased the content of brown materials and the chromaticity. Crude lipids were degraded by heat and converted into volatile aromatic ingredients. Crude lipids were degraded and decreased by 0.52% after the 5th and 7th. Crude proteins were also decomposed and converted to amino acid. Crude proteins after the 9th treatment were decreased by more than 85% as increased times of treatments. A bicyclogermacrene as aromatic material was decreased as increased treatment times, while but a aromatic caramel was increased.