• 한국식품영양과학회지
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• 제33권5호
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• pp.769-777
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• 2004

위염과 위궤양의 일차적 발병 인자로 알려진 Helicobacter pylori의 생육을 억제하고 urease 산물인 암모니아의 축적에 의한 위점막 손상을 완화시킬 목적으로 복분자로부터 H. pylori urease저해물질을 분리정제하고 소재화와 관련된 일부 성질을 규명하였다. 양념 채소류, 차류, 죽류, 건강채소류등의 식용식물, 약용식물, 허브 및 해조류, 총 173종으로부터 극성도에 따라 계통추출한 수용성인 냉수추출물(Fr, 1), methanol 추출물(Fr.4), 열수추출물(Fr.5) 519점을 대상으로 H. pylori urease 저해활성을 검색하였다. 1차 및 2차 저해활성 검색 결과 복분자의 70% acetone추출물이 약 24%의 가장 높은 저해활성을 나타내었으며, 이 추출물을 ethyl acetate와 butanol을 사용하여 ethyl acetate/DW layer(RCE/RCWl)와 butanol/DW layer(RCB/RCW2)로 순차 분획한 후 활성획분인 RCW2 내의 활성 본체를 확인할 목적으로 periodate oxidation과 pronase digestion을 실시한 결과 펩타이드 또는 단백질성 물질로 판명되었다. 저해활성 물질은 DEAE-Toyopearl 650C, Butyl-Toyopearl 650M 및 Sephadex LH-20순의 column chromatography에 의 해 분리 정제되었다. 분리 urease 저해물질, RCW2-IIIc $\alpha$는 HPLC의 gel permeation chromatography에 의해 비교적 순도 높은 분자량 약 13 kDa의 단일 물질임이 확인되었다. 저해활성물질은 열에 안정성을 보이 는 내열성 단백질임을 알 수 있었고 위내 단백분해효소인 pepsin에도 가수분해 저항성을 나타냄으로써 기능성식품의 소재로 높은 소재화 적성을 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권9호
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• pp.1216-1220
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• 2001

Effect of hydroquinone (HQ) on rumen urease activity was studied. Hydroquinone at concentrations of 0.01 ppm, 0.1 ppm, 1 ppm, and 10 ppm inhibited urease activity of intact rumen microbes in vitro by 25%, 34%, 55% and 64% respectively. In the presence of low concentrations of $\beta$-mercaptoethanol, rumen urease could be solubilized and partially purified. The Km for the enzyme was $2{\times}10^{-3}$ M with Vmax of $319.4{\mu}moles/mg$ min. The kinetics of inhibition with partially purified rumen urease was investigated. The result showed that the inhibitory effect was not eliminated by increasing urea concentrations indicating a noncompetitive effect in nature with an inhibition constant $1.2{\times}10^{-5}$ M. Hydroquinone at the concentration of 10 ppm produced 64% urease inhibition, did not affect ruminal total dehydrogenase and proteolytic enzyme (p>0.05), but increased cellulase activity by 28% (p<0.05) in vitro. These results indicated that hydroquinone was a effective inhibitor of rumen urease and could effectively delay urea hydrolysis without a negative effect. The inhibitor appeared to offer a potential to improve nitrogen utilization by ruminants fed diets containing urea.

• 아시안잔디학회지
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• 제6권1호
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• pp.23-28
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• 1992

Urea, the major N source of world agriculture involves a serious urea-N loss through NH$_3$volatilization. Approaches to decrease N loss include using urease inhibitors in view of the environmental protection and the increase of urea-N efficiency. The purpose of laboratory researches was toassess the potential value of urease inhibitors to increase urea-N efficiency in soil and Kentucky blue-grass(Poa Pratensis L.) turf. The activity of urease inhibitors Phenyiphosphorodiamjdate(ppD) and N-(n-butyl) thiophosphoric triamjde(NBPT) measured to break-down ammonia volatilization. The soil and turf used in this project were from the fairway in one of the Korean gof course. The researches were carried out for two weeks to measure the urease activities on urea hydrolysis under four temperatures (10~ 40$^{\circ}C$) and for one week on turfgrass using forced-draft system. Results indicated that Urea-N involves considerable loss through gaseous NH$_3$ by urease activities in plant-soil systems. Urease inhibitors PPD and NBPT have potential value for increasing N use efficiency by reduing NH$_3$ volatilization. NBPT deserves futher evaluation as fertilizer amendment than PPD use of urea in turf industries.

• Archives of Pharmacal Research
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• 제9권3호
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• pp.163-167
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• 1986

Twenty six urea analogues, most of which have already been approved for human use, were tested for their antiurease activity in vitro. Cell-free extracts obtained from a clinical isolate of Proteus mirabilis was used as the source of enzyme. Acetohydroxamic acid which is a proven potent urease inhibitor but not approved for human use was again shown to be the most active compound among the tested. Phenacemide, cycloserine, and deferoxamine were demonstrated to be moderate inhibitors. Oxtetracycline, trimethoprim, and cefamandole revealed a demonstrable antiruease activity, but only at very high concentrations. The antiurease activity of cycloserine, trimethoprim, and cefamandole was pH dependent-only active at acidic pH. The inhibitory activity of acetohydroxamic acid however was independent of change in pH. The inhibitory activity of acetohydroxamic acid however was independent of change in pH. Hydrogen ion concentration plays an important role in urease activity and acidification (pH 5. 5) alone eliminates approximately 65% of the enzymic activity. Adjustment of pH therefore appears to be an important adjunct in reducing unrease activity and should always be studied to maximize the effcacy of antiurease compounds under investigation.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2741-2747
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• 2012

A new series of 2,5-disubstituted-1,3,4-thiadiazoles 6a-i was synthesized by overnight stirring various 1,4-disubstituted thiosemicarbazides 5a-i in polyphosphoric acid followed by neutralization. The structures of newly synthesized compounds 5a-i and 6a-i were characterized by IR, $^1H$ and $^{13}C$ NMR, elemental analysis and mass spectrometric studies. All the synthesized compounds were evaluated for their urease and acetylcholine esterase inhibition activities. Thiosemicarbazides 5a-i are found to possess excellent potential for urease inhibition, more than the standard drug. Thiosemicarbazides 5a-i are more potent urease inhibitor than their cyclic analogues thiadiazoles 6a-i. Almost all of the compounds are excellent inhibitors of acetylcholine esterase. The inhibition of acetylcholine esterase of compounds 5a, 5c, 5d, 5g, 5i, 6e, 6f, 6g, and 6i is much more than that of standard drug.

• 생명과학회지
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• 제10권6호
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• pp.558-563
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• 2000

Effect of inhibitors on Vibrio parahaemolyticus cell growth and its urease activity was studied. The growth of the bacterium and the enzyme activity were inhibited by the addition of 0.02% p-hydroxymercuric benzoate, $HgCl_2$and $AgNO_3$. However, same concentration of boric acid, thallium acetate and $Pb(NO_3)_2$ did not affect the cell growth but inhibited urease activity by 25%, 29%, and 38%, respectively. Acetohydroxamic acid was the most potent inhibitor on cell growth by inhibiting 40% but did not affect urease activity. To investigate the effect of inhibitors on urease activity, urease was purified and confirmed on SDS-PAGE. The purified urease was inhibited 100% by the addition of 1 mM acetohydroxamic acid and $AgNO_3$but no inhibition was occurred by the addition of the same concentration of thallium acetate. and the addition of 0.01 mM of $HgCl_2$ and acetohydroxamic acid inhibited the purified urease activity by 39% and 24%, respectively. On 0.1 millimolar basic, acetohydroxamic acid and $HgCl_2$inhibited 4 times more active in urease inhibition than p-hydroxymercuric benzoate whereas no inhibition was occurred either thallium acetate or $Pb(NO_3)_2$.

• Journal of Animal Science and Technology
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• 제64권4호
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• pp.603-620
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• 2022

Human activities have caused an increase in greenhouse gas emissions, resulting in climate change that affects many factors of human life including its effect on water and food quality in certain areas with implications for human health. CH₄ and N₂O are known as potent non-CO₂ GHGs. The livestock industry contributes to direct emissions of CH₄ (38.24%) and N₂O (6.70%) through enteric fermentation and manure treatment, as well as indirect N₂O emissions via NH₃ volatilization. NH₃ is also a secondary precursor of particulate matter. Several approaches have been proposed to address this issue, including dietary management, manure treatment, and the possibility of inhibitor usage. Inhibitors, including urease and nitrification inhibitors, are widely used in agricultural fields. The use of urease and nitrification inhibitors is known to be effective in reducing nitrogen loss from agricultural soil in the form of NH₃ and N₂O and can further reduce CH₄ as a side effect. However, the effectiveness of inhibitors in livestock manure systems has not yet been explored. This review discusses the potential of inhibitor usage, specifically of N-(n-butyl) thiophosphoric triamide, dicyandiamide, and 3,4-dimethylpyrazole phosphate, to reduce emissions from livestock manure. This review focuses on the application of inhibitors to manure, as well as the association of these inhibitors with health, toxicity, and economic benefits.

• Animal Bioscience
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• 제34권12호
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• pp.2023-2033
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• 2021

Objective: The present study was conducted to assess the effect of urease inhibitor (hydroquinone [HQ]) and nitrification inhibitor (dicyandiamide [DCD]) on nitrogen (N) use efficiency of pig slurry for perennial ryegrass regrowth yield and its environmental impacts. Methods: A micro-plot experiment was conducted using pig slurry-urea ¹⁵N treated with HQ and/or DCD and applied at a rate of 200 kg N/ha. The flows of N derived from the pig slurry urea to herbage regrowth and soils as well as soil N mineralization were estimated by tracing pig slurry-urea ¹⁵N, and the N losses via ammonia (NH₃), nitrous oxide (N₂O) emission, and nitrate (NO₃^-) leaching were quantified for a 56 d regrowth of perennial ryegrass (Lolium perenne) sward. Results: Herbage dry matter at the final regrowth at 56 d was significantly higher in the HQ and/or DCD applied plots, with a 24.5% to 42.2% increase in ¹⁵N recovery by herbage compared with the control. Significant increases in soil ¹⁵N recovery were also observed in the plots applied with the inhibitors, accompanied by the increased N content converted to soil inorganic N (NH₄⁺+NO₃^-) (17.3% to 28.8% higher than that of the control). The estimated loss, which was not accounted for in the herbage-soil system, was lower in the plots applied with the inhibitors (25.6% on average) than that of control (38.0%). Positive effects of urease and/or nitrification inhibitors on reducing N losses to the environment were observed at the final regrowth (56 d), at which cumulative NH₃ emission was reduced by 26.8% (on average 3 inhibitor treatments), N₂O emission by 50.2% and NO₃^- leaching by 10.6% compared to those of the control. Conclusion: The proper application of urease and nitrification inhibitors would be an efficient strategy to improve the N use efficiency of pig slurry while mitigating hazardous environmental impacts.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1999년도 춘계 학술대회지
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• pp.73-74
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• 1999

• Archives of Pharmacal Research
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• 제21권1호
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• pp.6-11
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• 1998

The activities of two types of antiulcer agents against 9 strains of Helicobacter pylori (H. pylori) were determined by the agar dilution method. The antiulcer agents were YJA20379, a newly synthesized proton pump inhibitor developed by Yung-jin Pharmaceutical company, and omeprazole. Both compounds were found to have significant activities against this organism. The MIC values of YJA20379 and omeprazole were 11.7 and $31.25{\mu.g/ml}$ respectively. In addition, the inhibitory potency of both compounds was investigated on H. pylori urease which is believed to be an important colonization and virulence factor in the pathogenesis of gastritis and peptic ulcers. These compounds dose-dependently inhibited urease extracted with distilled water and their $IC_50$ values were $16.4{\times}10^{-5} M and 14.3{\times}10^{-5}M,$ respectively. In addition, a pH-dependent study to determine whether inhibitory potency would be activated by acid condition was performed. It was found that unlike omeprazole, YJA20379 was not affected by acid condition. To determine the inhibition pattern and optimal concentration of substrate, kinetics were evaluated at various pH levels (pH 5.0, 7.0, and 8.5). The data show that YJA20379 noncompetitively inhibited H. pylori urease and $K_M/K_i$values were 0.96 $mM/60{\mu}M (pH 5.0), 0.56 mM/141.5 {\mu}M (pH 7.0)$, and $1.94mM/34{\mu}M (pH 8.5)$, respectively. Based on data obtained, it is concluded that YJA20379 is a significant inhibitor of H. pylori growth and urease and therefore, taking these results into consideration, YJA20379 might be a beneficial therapy for gastritis and peptic ulcers induced by H. pylori.