• 한국식품저장유통학회지
• /
• 제14권1호
• /
• pp.61-66
• /
• 2007

일시에 대량 수확되는 양파의 소비를 촉진시키고 식품의 원 부재료로서의 이용성을 제고하기 위하여 $50^{\circ}C$ 열풍건조, $40^{\circ}C$ 진공건조, $-70^{\circ}C$ 동결건조 중의 품질특성 변화를 조사하였다. 수분함량은 진공건조가 건조 5일째에 수분함량 5.23%를 유지하여 가장 빨리 분말화가 가능하였다. 또한 중량감소율은 동결건조가 건조 7일째 중량감소율이 90.0%를 나타내었다. 갈색도는 동결건조가 건조 7일째에 흡광도 1.173으로 가장 낮은 갈색도 변화를 보였다. 색도 중 백색도(L값)는 열풍건조가 큰 변화를 보였고, 적색도(a값)과 황색도(b값)의 경우도 마찬가지로 열풍건조가 변화가 크게 일어나는 경향을 나타내었다. Vitamin C의 함량은 건조가 진행됨에 따라 상대적으로 증가하였다. 유리당은 fructose, glucose, sucrose가 주된 유리당이었다. Citric acid가 주된 유기산으로 동결건조가 1,965 mg%로 가장 높게 나타났다. 유리아미노산은 L-arginine, ${\beta}-alanine$, alanine, L-threonine등이 주된 유리아미노산으로 확인 되었다. 본 연구의 결과로 양파건조분말제조는 $-70^{\circ}C$ 동결건조가 가장 바람직한 방법으로 판단된다.

• 한국미생물·생명공학회지
• /
• 제2권2호
• /
• pp.121-122
• /
• 1974

• 한국미생물·생명공학회지
• /
• 제23권6호
• /
• pp.671-677
• /
• 1995

An extracellular enzyme showing lytic activity on E. coli peptidoglycan had been isolated from Bacillus sp. BL-29. The lytic enzyme was purified to homogeneity by ion-exchange chromatography and gel filtration, with a recovery of 5%. The enzyme was monomeric and had an estimated molecular weight of 31,000 Da. The mode of action of the purified enzyme was also investigated. When the purified lytic enzyme was incubated with cell wall peptidoglycan, N-terminal amino groups were released without the release of reducing groups. The N-terminal amino acid released was identified as dinitrophenylalanine (DNP-alanine) by analysis of terminal amino acid by dinitrophenylation method. This result suggests that the lytic enzyme should be a kind of N-acetylmura-myl-L-alanine amidase.

• Bulletin of the Korean Chemical Society
• /
• 제26권6호
• /
• pp.989-992
• /
• 2005

Dynamic kinetic resolution of $\alpha$-bromo carboxylic acid derivatives in nucleophilic substitution with chiral $\alpha$-amino ester nucleophiles in the presence of TBAI and DIEA has been investigated for stereoselective syntheses of 1,1'-iminodicarboxylic acid derivatives. Nucleophilic substitutions with various chiral $\alpha$-amino esters gave iminodiacetates 2-8 with stereoselectivities up to 87 : 13 dr. Also, the reactions of N-($\alpha$-bromo-$\alpha$-phenylacetyl)-L-alanine methyl ester with L-alanine, D-alanine and glycine methyl ester nucleophiles afforded N-carboxyalkyl dipeptide analogues 10-12 up to 90 : 10 dr.

• 공업화학
• /
• 제33권4호
• /
• pp.425-430
• /
• 2022

L-alanine (LA, as an amino acid residue) pentamer model was used to investigate changes in the dihedral angle, intramolecular hydrogen bonding and formation energies during structural optimization. LA pentamers having four conformation types [𝛽: 𝜑/𝜓=t-/t+, 𝛼: 𝜑/𝜓=g-/g-, PP_II: 𝜑/𝜓=g-/t+ and P-like: 𝜑/𝜓= g-/g+] were carried out by quantum chemical calculations (QCC) [B3LYP/6-31G(d,p)]. In LA, 𝛽, 𝛼, and P-like types did not change by optimization, having an intra-molecular hydrogen bond: NH⋯OC (H-bond), and PP_II types in the absence of H-bond were transformed into P-like at the designated 𝜓 of 140°, and to 𝛽 at that of 160° or 175°. P-like and 𝛼 were about 0.5 kcal/mol/mu more stable than 𝛽. In order to understand the processes of the transformations, the changes of 𝜑/𝜓, distances of NH-OC (d_NH/CO) and formation energies (𝜟E, kcal/mol/mu) were examined.

• 한국동물학회지
• /
• 제4권2호
• /
• pp.20-24
• /
• 1961

The present experiment was conducted to investigate the rate of oxygen consumption in relation to the several amino acids in the Mang-Kong frog ,Gallula tornieri VOGT. 1. When the liver tissue was suspended in the Ringer's solution (0.85% NaCl), the amount of oxygen consumption per hour was 0.043$\mu$l/mg , whereas when it was suspended in M/15, pH 5.8 phosphate buffer the oxygen consumption reached 0.93$\mu$l/mg. 2. When 0.5ml of 1% alanine and 0.5ml of 0.5% arginine were used as respiratory material the amount of oxygen consumption increased remarkably, while on the other hand glycine showed little influence on the amount of oxygen consumption. 3. When 0.5ml of 0.1% , 0.5% alanine-arginine mixture, 0.5ml of 0.1% , 0.5% alanine-glycine mixture and 0.5ml of 1 % arginine-glycine were added the oxygen consumption in the liver tissue increased somewhat in comparison to the case in which single amino acid was used. 4. Glycine appeared to have influence on the respiration of the liver tissue but the amount of oxygen consumption increased as the concentration of arginine-glycine mixture increased, whereas the rate of oxygen consumption increased remarkably as alaninie-glycine mixture decreased. It was evidenced that in the combination of alanine-arginine the rate of oxygen consumption increased as the concentration of the mixture decreased and vice versa.

• Journal of Nutrition and Health
• /
• 제42권8호
• /
• pp.732-739
• /
• 2009

Metabolic syndrome has been strongly associated with elevated alanine aminotransferase (ALT), a surrogate of nonalcoholic fatty liver disease. We investigated the relationship between metabolic syndrome and elevated ALT in the general Korean population. The study sample was comprised of 4,781 Korean adults who had participated in the 2005 Korean National Health and Nutrition Examination Survey. Metabolic syndrome was defined by National Cholesterol Education Program for Adult Treatment Panel III. Elevated ALT was defined as an enzyme activity > 40 IU/L for men, and > 31 IU/L for women. ALT was measured by enzymatic methods. Among participants, 425 (8.9%) subjects displayed elevated ALT. The odds ratios (ORs) for elevated ALT increased in subjects with obesity or one of components of metabolic syndrome such as abdominal obesity, high blood pressure, high fasting glucose, high triglyceride, and low HDL cholesterol after adjusting for age and sex. The unadjusted OR for elevated ALT increased according to the number of components of metabolic syndrome (OR = 1.5, 95% CI: 0.96-2.32 for 1 component; OR = 3.0, 95% CI: 1.98-4.61 for 2 components; OR = 6.3, 95% CI: 4.29-9.35 for ${\geq}3$ components; p for trend < 0.0001). This trend did not differ after adjustments for putative risk factors including age, sex, BMI, smoking status, and alcohol intake. Metabolic syndrome is implicated as a strong risk factor of elevated ALT in Korean adults.

• 한국미생물·생명공학회지
• /
• 제46권4호
• /
• pp.416-424
• /
• 2018

강원도에서 생산된 과일을 사용하여 식초를 제조하여, 초산 발효에 의하여 변화되는 주요 대사체 및 향기 성분을 조사하였다. 머루 복분자 식초에서는 초산 발효에 의하여 ${\text\tiny{L}}$-alanine의 함량 변화가 가장 크게 변화하였으며, 초산은 향기 성분 전체 함량 중 43%로 가장 높은 함량을 나타냈고, 초산 발효 후 ethyl acetate, isoamyl acetate 등의 에스테르 화합물의 함량이 증가하였다. 오미자 막걸리 식초의 경우 초산발효에 의하여 linalool, hexanoic acid 등이 생성되었고 테르펜류 화합물이 41.5%로 대부분을 차지하였다. 머루 복분자 식초의 경우와 유사하게 ${\text\tiny{L}}$-alanine의 함량 변화가 가장 큰 것으로 나타났다. 머루 복분자 식초에서는 ethyl acetate, 오미자 막걸리 식초에서는 감귤향을 내는 terpinel-4-ol, 꽃향기를 내는 ${\alpha}$-terpineol 등 테르펜류의 성분들이 각 식초의 향기 특성에 큰 영향을 나타내는 것으로 확인되었다.

• Bulletin of the Korean Chemical Society
• /
• 제32권4호
• /
• pp.1258-1262
• /
• 2011

A new organogelator, L-Alanine dihydrazide derivative can self-assemble in various organic solvents and turned them into thermally reversible physical supramolecular organogels at extremely low concentrations (< 2 wt %). The gel-sol phase transition temperatures ($T_{GS}$) were determined as a function of gelator concentration and the corresponding enthalpies (${\Delta}H_g$) were extracted. Scanning electron microscopy (SEM) measurements revealed that the interspaces of fiber-like network structures were diminished with the increasing of the LMOG concentration. FT-IR spectroscopy studies revealed that hydrogen-bonding and hydrophobic interaction were the driving forces for the formation of the gels. Based on the data of XRD and molecular modeling, the possible packing modes for the formation of organogelator aggregates were proposed.

• Journal of Microbiology and Biotechnology
• /
• 제16권9호
• /
• pp.1416-1421
• /
• 2006

We identified a gene encoding the N-acetylmuramoyl L-alanine amidase (amiB) of Vibrio anguillarum, which catalyzes the degradation of peptidoglycan in bacteria. The entire open reading frame (ORF) of the amiB gene was composed of 1,722 nucleotides and 573 amino acids. The deduced amino acid sequence of AmiB showed a modular structure with two main domains; an N-terminal region exhibiting an Ami domain and three highly conserved, continuously repeating LysM domains in the C-terminal portion. An amiB mutant was constructed by homologous recombination to study the biochemical function of the AmiB protein in V. anguillarum. Transmission electron microscopy (TEM) revealed morphological differences, and that the mutant strain formed trimeric and tetrameric unseparated cells, suggesting that this enzyme is involved in the separation of daughter cells after cell division. Furthermore, inactivation of the amiB gene resulted in a marked increase of sensitivity to oxidative stress and organic acids.