• 한국자원식물학회지
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• 제23권6호
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• pp.519-525
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• 2010

Chlorogenic acid, formed of an ester of caffeic acid and quinic acid, which is naturally abundant in many plant species, was used as a model O-dihydoxy phenolic compound. In the previous study, we have reported that the isolated constituent from Apocynum venetum leaves has an inhibitory effect on $Cu^{2+}$-induced oxidative modification of low-density lipoprotein (LDL). Among them, chlorogenic acid showed the most potent anti-LDL oxidative activity than other compounds. For the reason, we investigated the inhibitory effect of the chlorogenic acid on $Cu^{2+}$-induced oxidative modification of LDL, monitored a lag time in the conjugated-diene formation and TBARS formation, and measured TNBS free amino acid group, and form cell formation in vitro system. The TBARS- and diene- formation were strongly inhibited by chlorogenic acid ($0{\sim}100\;{\mu}g/ml$) with dose dependent manner. On the other hand, TNBS reactive lysine amino groups on LDL oxidation were protected by chlorogenic acid- treated cell group. Therefore, chlorogenic acid inhibited to cholesterol accumulation in the isolated peritoneal macrophage.

• Asian-Australasian Journal of Animal Sciences
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• 제30권1호
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• pp.42-50
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• 2017

Objective: Two trials were conducted in order to examine the effects of level of supplemental methionine on productive performance, dietary energetic, plasma amino acid concentration, and digestive function. Methods: Dietary treatments consisted of a steam-flaked corn-based diet containing urea as the only source of supplemental nitrogen supplemented with no supplemental amino acid (control), or control plus 1.01% lysine and 0.032%, 0.064%, 0.096%, or 0.128% methionine. In Trial 1, 150 Holstein steer calves ($127{\pm}4.9kg$) were utilized to evaluate the influence of treatments on growth-performance, dietary energetic, plasma amino acid concentration during the first 112 days of growing period. During the initial 56-d period calves received the 5 experimental diets. During the subsequent 56-d period all calves were fed the control diet. Results: During the initial 56-d period, methionine supplementation increased (linear effect, p<0.01) plasma methionine. In the presence of supplemental lysine, increases on level of methionine in diet did not affect average daily gain. However, increased gain efficiency (quadratic effect, p = 0.03) and estimated dietary net energy (NE; linear effect, p = 0.05). Estimated metabolizable methionine supply was closely associated ($R^2=0.95$) with efficiency NE utilization for maintenance and gain. During the subsequent 56-d period, when all calves received the control diet (no amino acid supplementation), plasma amino acid concentrations and growth performance was not different among groups. However, the effects of methionine supplementation during the initial 56-period carried over, so that following a 56-d withdrawal of supplementation, the overall 112-d effects on gain efficiency (quadratic effect, p = 0.05) dietary NE (linear effect, $p{\leq}0.05$) remained appreciable. In Trial 2, 5 cannulated Holstein steers were used to evaluate treatment effects on characteristics of digestion and amino acid supply to the small intestine. There were no treatment effects on flow of dietary and microbial N to the small intestine. Postruminal N digestion increased (p = 0.04) with increasing level of supplemental methionine. Methionine supplementation linearly increased (p<0.01) duodenal flow of methionine. Likewise, lysine supplementation increased an average of 4.6% (p = 0.04) duodenal flow of lysine. In steers that received non-supplemented diet, observed intestinal amino acid supply were in good agreement with expected. Conclusion: We conclude that addition of rumen-protected methionine and lysine to diets may enhance gain efficiency and dietary energetics of growing Holstein calves. Observed amino acid supply to the small intestine were in good agreement with expected, supportive of NRC (2000, Level 1).

• Asian-Australasian Journal of Animal Sciences
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• 제23권8호
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• pp.1013-1021
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• 2010

This study was conducted to determine the effects of amino acid-enriched ruminally protected fatty acid (AARPFA) on plasma fatty acids and amino acids, growth performance and carcass characteristics of Korean native steers (Hanwoo) by simultaneous supply of fatty acids and limiting amino acids (methionine and lysine). Eighteen finishing Hanwoo steers, 18 months of age and weighing an average of $459.0{\pm}38.9\;kg$, were used for studies of the metabolism of plasma fatty acids and amino acids during supplementation of AARPFA. Also, 45 finishing Hanwoo steers, 16 months of age and weighing an average of $408.6{\pm}26.5\;kg$, were used for growth performance and carcass characteristics during supplemention of AARPFA. There were three treatments which comprised a basal diet supplemented with AARPFA at 0 g (T1), 50 g (T2) or 100 g (T3), respectively. Concentrations of saturated, unsaturated and total fatty acids in plasma were increased in T3 compared with other treatments (p<0.05). Concentrations of methionine and lysine in plasma were linearly increased with increasing levels of AARPFA (p<0.01). Average daily gain, dry matter intake and feed conversion ratio were not different among the treatments. Marbling score measured by ultra-sound scanning was higher in T3 than in T1 at 24 months of age (p<0.05). Rib eye area, back fat thickness, yield index and yield grade score were similar across the treatments. Marbling score and quality grade score were higher in T3 compared with other treatments (p<0.01). Thus, plasma fatty acids, methionine and lysine metabolism were affected by supplementing with 100 g of AARPFA which also had positive effects on marbling score and meat quality grade of finishing Hanwoo steers.

• Animal Bioscience
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• 제35권10호
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• pp.1556-1565
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• 2022

Objective: Tan lambs (n = 36, 3 mo old, 19.1±0.53 kg) were used to assess effects of dietary guanidinoacetic acid (GAA) and rumen-protected methionine (RPM) on growth performance, carcass traits, meat quality, and serum parameters. Methods: Lambs were randomly assigned to three treatment groups, with 6 pens per group and 2 lambs per pen. Dietary treatments were: basal diet alone (I); basal diet supplemented with 0.08% GAA+0.06% RPM (II); and basal diet supplemented with 0.08% GAA+0.08% RPM (III). Diets were provided three times a day for 90 d. Intake per pen was recorded daily and individual lamb body weight (BW) was measured monthly. Carcass traits were measured after slaughter and meat quality at the end of the experiment, blood samples were taken on a subgroup of lambs for analysis of indicators mostly related to protein metabolism. Results: Final BW and average daily gain for the first and second month, and for the entire experiment were greater in Treatment II compared to Treatment I (p<0.05), whereas feed to gain ratio was lower (p<0.05). Treatment II had the optimal dressing percentage and net meat weight proportion, as well as crude protein and intramuscular fat concentrations in muscles. Treatment II improved meat quality, as indicated by the greater water holding capacity, pH after 45 min and 48 h, and lower shear force and cooking loss. Dietary supplementation of GAA and RPM also increased the meat color a^* and b^* values at 24 h. Finally, Treatment II increased total protein, and serum concentrations of albumin and creatinine, but decreased serum urea nitrogen concentrations, indicating improved protein efficiency. Conclusion: In this study, 0.08% GAA+0.06% RPM supplementation improved growth performance and meat quality of Tan lambs.

• 대한화학회지
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• 제31권5호
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• pp.457-463
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• 1987

2-브로모프로피오닐화된 수지를 이용해 insulin A (1-21) 사슬을 합성하였다. 시스테인의 결사슬은 각각 acetamidomethyl, benzyl, 그리고 benzhydryl기로 보호하였으며 그루타민과 아스파라긴은 p-nitrophenyl기로 활성화하여 합성에 이용하였다. 매 짝지음단계마다 DCC/HOBT coupling agent로 각 아미노산을 축합하였으며 반응의 완결여부는 닌히드린시험으로 측정하였다. 생성물은 NH$_3$/MeOH-Dioxane(v/v 1:1)로 수지로부터 분리하여 DEAE Sephadex A-25와 Sephadex LH-20으로 정제하였으며 최종생산물은 HPLC, electrophoresis로 확인한 결과 순수한 것(>99.9%)으로 나타났으며 총수득율은 6%이었다.

• Bulletin of the Korean Chemical Society
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• 제8권1호
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• pp.15-19
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• 1987

Preparation of optically pure (3R, 4R)-4-acetoxy-3-[(1R)-1-hydroxyethyl]azetidin-2-o ne derivatives, which can be employed as starting materials for synthesis of carbapenem and penem antibiotics, was established in high efficiency from 6-amino-penicillanic acid (6-APA). 6-APA was diazotized and brominated to give 6, 6-dibromopenicillanic acid and its methyl ester was metalated with methylmagnesium bromide and condensed with acetaldehyde. The product, methyl 6-bromo-6-(1-hydroxyethyl)penicillanate was reduced with Zn-$NH_4Cl-NH_4OH$-acetone efficiently to give methyl 6-(l-hydroxyethyl)-penicillanate, which was protected either with ${\beta},{\beta},{\beta}$ -trichloroethoxycarbonyl group or with t-butyldimethylsilyl group. The thiazolidine rings of these compounds were cleaved by treatment of mercury(II) acetate in acetic acid and permangante in acetone in sequence to afford the desired optically pure final products.

• Journal of Animal Science and Technology
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• 제50권2호
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• pp.199-208
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• 2008

본 연구는 보호아미노산 추가 공급이 비유중기 착유우의 반추위 발효 성상 및 유생산량과 유성분 등의 생산성 변화를 알아보기 위하여 in vitro 시험과 in vivo 시험을 각각 실시하였다. In vitro 시험은 각각 4g의 공시사료를 이용하였으며, 처리구에는 보호라이신(PRLys, 2.71 %)과 보호메치오닌(PRMet, 0.90%)을 3:1로 혼합하여 첨가한 후 48시간동안 배양한 후 처리구와 대조구의 pH와 건물소화율을 확인하였다. 또한 In vivo 시험은 3:1로 혼합한 보호라이신 (PRLys, 2.71%)과 보호메치오닌(PRMet, 0.90%) 100g을 1일 2회로 나누어 비유 중기 착유우에 오전과 오후 착유 시 정량급여 한 후 생산되는 우유의 양 그리고 유성분의 변화를 조사하였다. 아미노산의 추가 급여로 인한 in vitro 반추위 pH와 건물소화율은 배양시간이 경과함에 따라 감소하는 경향을 나타냈으나 대조구에 비하여 유의성은 나타나지 않았다. 따라서 본 연구에서 사용된 보호아미노산은 반추위 미생물의 건물분해 능력 등 반추위 발효성상에 악 영향을 미치지 않은 것으로 판단된다. 비유중기 착유우에 보호아미노산 급여기간에 따른 유생산량은 시간이 지남에 따라 대조구와 처리구에서 모두 감소하는 경향을 보였으나, 이는 시험기간이 경과함에 따른 착유일수 증가로 인한 자연감소로 보여지며, 대조구에서 보다 처리구에서의 유량감소율이 적었다. 4% FCM과 유단백생성량은 대조구에서 각각 11.25%, 11.09% 그리고 처리구에서 6.16%, 5.47%의 감소를 나타내어 대조구보다 처리구에서 감소 비율이 낮았다. 보호아미노산 첨가 시 우유중 지방생성량은 대조구(0.79kg)에 비하여 처리구(1.10kg)에서 유의한 차이를 나타내었다(P<0.05). 이상의 결과를 종합해 볼 때 in vitro의 경우 보호아미노산 첨가시 반추위 내 발효성상에 문제가 없었고, 비유중기 착유우를 대상으로 한 in vivo 시험에서는 처리구에서 산유량 및 유성분의 감소가 대조구보다 적었으며 이는 고능력우의 비유중기 시기에 보호아미노산을 급여할 경우 산유량 및 유성분의 감소비율을 효과적으로 개선시킬 수 있는 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제22권5호
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• pp.659-666
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• 2009

Metabolizable protein (MP) supply and amino acid balance in the intestine were manipulated through selection of highly digestible rumen-undegradable protein (RUP) sources and protected methionine (Met) supplementation. Four ruminallycannulated, multiparous Holstein cows averaging 193${\pm}$13 days in milk were used in a 4${\times}$4 Latin square design to assess N utilization and milk production responses to changes in RUP level, post-ruminal RUP digestibility and protected Met supplementation. Treatments were A) 14.0% crude protein (CP), 8.0% rumen degradable protein (RDP) and 6.0% RUP of low intestinal digestibility (HiRUP-LoDRUP); B) 14.1% CP, 8.1% RDP and 6.0% RUP of high intestinal digestibility (HiRUP-HiDRUP); C) 13.1% CP, 7.9% RDP and 5.2% RUP of high intestinal digestibility (LoRUP-HiDRUP), and D) 13.1% CP, 7.9% RDP and 5.2% RUP of high intestinal digestibility plus rumen escape sources of Met (LoRUP-HiDRUP+Met). Experimental diets were formulated to have similar concentrations of RDP, net energy of lactation ($NE_L$), neutral detergent fiber (NDF), acid detergent fiber (ADF), calcium, phosphorus and ether extract using the NRC model (2001). Results showed that dry matter intake (DMI), production of milk fat and protein were similar among treatments. Milk production was similar for diet HiRUP-LoDRUP, HiRUP-HiDRUP and LoRUP-HiDRUP+Met, and significantly higher than diet LoRUP-HiDRUP. Milk fat and protein percentage were higher for cows receiving HiDRUP treatments, with the greatest increases in the diet LoRUP-HiDRUP+Met. There was no significant change in ruminal pH, $NH_3g-N$ and volatile fatty acid (VFA) concentration among all treatments. Apparent digestibility of dry matter (DM), CP, NDF and ADF and estimated bacterial CP synthesis were similar for all treatments. Nitrogen intakes, blood and milk urea-N concentrations were significantly higher for cows receiving HiRUP diets. Urine volume and total urinary N excretion were significantly lowered by LoRUP diets. Lowering dietary RUP level while supplementing the highly digestible RUP source with rumen escape sources of Met resulted in similar milk production, maximal milk fat and protein concentration and maximum N efficiency, indicating that post-ruminal digestibility of RUP and amino acid balance in the small intestine can be more important than total RUP supplementation.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.195.2-195.2
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• 2003

The CH$_2$Cl$_2$ fraction of the bark of Machilus thunbergii Sieb. et Zucc. (Lauraceae) significantly protected primary cultures of rat cortical cells exposed to the excitotoxic amino acid, L-glutamate. Several lignans including (-)-isoguaiacin, meso- dihydroguaiaretic acid, machilin A, (+)-galbelgin, licarin A, (-)-sesamin, and (+)-guaiacin were isolated from the CH$_2$Cl$_2$ fraction using by bioactivity-guided isolation techniques. Among these lignans, (-)-isoguaiacin, meso-dihydroguaiaretic acid, licarin A and (+)-guaiacin had significant neuroprotective activities against glutamate-induced toxicity in primary cultures of rat cortical cells at concentration ranging from 0.1 ${\mu}$M to 10.0 ${\mu}$M. (omitted)

• BMB Reports
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• 제30권2호
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• pp.113-118
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• 1997

Aspartase from Hafnia alvei was inactivated by N-ethylmaleimide (NEM) and 5,5' -Dithiobis-(2-znitrobenzoic acid) (DTNB) following pseudo-first order kinetics. Their apparent reaction orders were 0.83 and 0.50 for NEM and DTNB modifications, respectively, indicating that inactivation was due to a sulfhydryl group in the active site of aspartase and participation of the sulfhydryl group in an essential step in the catalytic reaction. When aspartase was modified by DTNB, the enzyme activity was restored by dithiothreitol treatment, indicating that cysteine residuetsl islarel possibly at or near the active site. The pH-dependence of the inactivation rate by NEM suggested that an amino acid residue having pK value of 8.3 was involved in the inactivation. When aspartase was incubated with NEM and L-aspartate together, L-aspartate markedly protected the enzyme from inactivation by NEM, but the other reagents used did not.