• 한국작물학회지
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• 제47권4호
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• pp.328-334
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• 2002

A Lindernia dubia (L.) Pennell var. dubia accession from Jeonnam province, Korea was tested for resistance to sulfonylurea (SU) herbicides, imazosulfuron and pyrazosulfuron-ethyl in whole-plant response bioassay. The accession was confirmed resistant to both herbicides. The $GR_{50}$ (herbicide concentration that reduced shoot dry weight by 50%) values of resistant accession were 264 and 19 times higher to imazosulfuron and pyrazosulfuronethyl, respectively, than that of the standard susceptible accession. The surviving resistant L. dubia after pyrazosulfuron-ethyl + molinate application can be controlled by sequential applications of soil-applied herbicides, butachlor, dithiopyr, pyrazolate, and thiobencarb and foliar herbicides, bentazon. Sulfonylurea-based mixtures such as mixtures of azimsulfuron + anilofos, bensulfuron-methyl + oxadiazon, pyrazosulfuron-ethyl + fentrazamide, and pyrazosulfuron-ethyl + anilofos + carfentrazon can also be used to control the surviving resistant L. dubia. However, use of these mixtures should be restricted to a special need basis. Thus, we suggest that sequential applications of non-SU-based mixtures such as butachlor + pyrazolate and MCPB + molinate + simetryne be used to control the surviving resistant L. dubia after SU herbicide applications. Rice yield was reduced 24 % by resistant L. dubia that survived after the pyrazosulfuron-ethyl + molinate application compared with pyrazolate + butachlor in transplanted rice culture. In vitro ALS activity of the resistant biotype was 40 and 30 times more resistant to imazosulfuron and pyrazosulfuron-ethyl, respectively, than the susceptible biotype. Result of in vitro ALS assay that the resistance mechanism of L. dubia to SU herbicides may be due, in part, to an alteration in the target enzyme, ALS.

• 한국잡초학회지
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• 제17권2호
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• pp.135-138
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• 1997

Sulfonylureas are highly active herbicides which can be applied at very low rate(10-50g/ha) to control broadleaf weeds. The nature of this category of compound is, however, very unstable toward hydrolysis. Therefore, the preparation of these compounds as liquid formulation was not possible. Most of the current formulations of sulfonylurea are in dry forms such as water dispersible granule or wettable powder. Even in these dry forms, the active ingredients also encounter significant chemical decomposition. This study involves the preparation of the sulfonylurea salts by reacting the parent compound with base such as sodium hydroxide. The salt becomes stable toward hydrolysis and it turns soluble when diluted with water. This discovery makes the preparation for liquid formulation or soluble granule of sulfonylurea possible. The stoichiometry of base added to the neutral sulfonylurea is controlled quite precisely. The base has to be added enough to quench the acidic impurities in the technical material and to convert the active ingredient into salt. However, the base should not be overused to cause further saponification of the sulfonylurea salts. The chemical nature of these compounds is presented and the chemical reaction is described. New soluble liquid formulation and solid granule formulation of sulfonylurea are suggested.

• 한국환경농학회지
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• 제8권2호
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• pp.136-141
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• 1989

Sulfonylurea계 화합물의 합성에 필요한 sulfonylisocyanate는 sulfonamide에 $COCl_2$를 반응시켜 얻는 것이 보통이나 본 실험에서는 oxalylchloride를 phosgen 대신 이용하여 sulfonyloxamoylchloride를 합성하고 이것을 열분해하여 얻었다. 이렇게 하여 얻는 sulfonylisocyanate는 각종 아민과 반응하여 높은 수율로 sulfonylurea를 생성하였다.

• 한국작물학회지
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• 제48권4호
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• pp.286-291
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• 2003

Monochoria vaginalis is one of the most troublesome resistant weeds in Korean rice culture. Thus, the objectives of this study were to evaluate the response of M. vaginalis resistant to sulfonylurea(SU) herbicides and to determine alternative herbicides for the control of resistant M. vaginalis in direct seeded and transplanted rice culture in Korea. In greenhouse studies, the resistant biotype was 31-, 38-, 3172-, and 7-fold more resistant to ben-sulfuron-methyl, cyclosulfamuron, imazosulfuron, and pyrazosulfuron-ethyl, respectively, than the susceptible biotype, indicating cross-resistance to the SU herbicides used in this study. Non-SU herbicides, butachlor, carfentrazone-ethyl, mefenacet, pretilachlor, pyrazolate, and thiobencarb, several SU herbicide-based mixtures, ethoxysulfuron plus fentrazamide, pyrazosulfuron-ethyl plus pyrazolate plus simetryn, and non-SU herbicide-based mixtures, pyrazolate plus butachlor, pyrazolate plus pretilachlor, simetryn plus molinate, carfentrazone-ethyl plus butachlor, and carfentrazone-ethyl plus thiobencarb can be used to control both the resistant and susceptible biotypes of M. vaginalis when applied before the second leaf stage. In the field experiment, the resistant biotype of M. vaginalis that survived from the paddy fields treated with a SU herbicide-based mixture could effectively be controlled by using mixtures of bentazone plus MCPA, bentazone plus mecoprop-P, and bentazone plus 2,4-D when applied at 2 or 4 main leaves. Our results suggest that the SU-resistant M. vaginalis had not developed multiple resistances to herbicides with different modes of action. In particular, bentazone plus MCPA and bentazone plus mecoprop-P were effective control measures after failure to control resistant M. vaginalis in Korean rice culture.

• BMB Reports
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• 제28권3호
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• pp.265-270
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• 1995

Acetolactate synthase (ALS, EC 4.1.3.18) is the first common enzyme in the biosynthesis of leucine, isoleucine, and valine. It is the target enzyme for several classes of herbicides, including the sulfonylureas, the imidazolinones, the triazolopyrimidines, the pyrimidyl-oxy-benzoates and the pyrimidyl-thio-benzens. The sulfonylurea-resistant ALS gene (SurB) from Nicotiana tabaccum [Lee et al. (1988) The EMBO J. 7, 1241-1248] was cloned into the bacterial expression plasmid pT7-7. The resulting recombinant plasmid pT7-ALS was used to transform an ALS-deficient Escherichia coli strain MF2000. MF2000 cells transformed with pT7-ALS grew in the absence of valine and isoleucine. ALS activities of 0.042 and 0.0002 ${\mu}mol/min/mg$ protein were observed in the crude extracts prepared from MF2000 cells transformed with plasmids pT7-ALS and pT7-7, respectively. In addition, the former crude extract containing mutant ALS was insensitive to inhibition by K11570, a new chemical class of herbicides. $IC_{50}$ values for K11570 were $0.13{\pm}0.01$ mM. For comparison, a plasmid pTATX containing the wild-type Arabidopsis thaliana ALS coding sequences was also expressed in MF2000. ALS activities of 0.037 ${\mu}mol/min/mg$ protein were observed, and the wild type ALS was sensitive to two different classes of herbicides, K11570 and ALLY, a sulfonylurea. $IC_{50}$ values for K11570 and ALLY were $0.63{\pm}0.07$ and $80{\pm}5.6$ nM, respectively. Thus, the results suggest that the sulfonylurea-resistant tobacco ALS was functionally expressed in the bacteria, and that K11570 herbicides bind to the regulatoty site of ALS enzymes.

• BMB Reports
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• 제31권3호
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• pp.287-295
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• 1998

Acetolactate synthase (ALS) is the first common enzyme in the biosynthesis of L-Ieucine, L-isoleucine, and L-valine. The sulfonylurea-resistant ALS gene from Nicotiana tabacum was cloned into the bacterial expression vector pGEX-2T. The resulting recombinant plasmid pGEX-ALS3 was used to transform Escherichia coli strain XL1-Blue, and the mutant tobacco ALS (mALS) was expressed in the bacteria as a protein fused with glutathione S-transferase (GST). The fusion product GST-mALS was purified in a single step on a glutathione-Sepharose column. ALS activities of 0.9-2.5 ${\mu}mol/min/mg$ protein were observed in the GST-mALS, and the Km values for pyruvate, FAD, and TPP were 10.8-24.1, $(1.9-8.9){\times}10^{-3}$, and 0.14-0.38 mM, respectively. The purified GST-mALS was resistant to both the sulfonylurea and the triazolopyrimidine herbicides, and lost its sensitivity to end products, L-valine and L-leucine. For comparision, the tobacco wild-type recombinant ALS fused with GST, GST-wALS, was also characterized with respect to its pyruvate and cofactor bindings. These results suggest that the purified mutant recombinant tobacco ALS was functionally active, that the mutations resulting in herbicide resistance has affected pyruvate and cofactor bindings," and that the two classes of herbicides interact at a common site on the plant ALS.

• 농약과학회지
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• 제11권4호
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• pp.269-275
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• 2007

4개의 서로 지역 계통별 sulfonylurea(SU)계 제초제 저항성 물달개비의 저항성 정도 차이를 구명하기 위하여 SU계 제초제들에 대한 식물체 및 acetolactate synthase(ALS) 반응 차이를 감수성 계통과 비교 분석하였다. 나주, 논산, 김제 지역에서 채집된 저항성 물달개비들은 SU계 제초제들의 기준량에서 거의 영향을 받지 않았다. 사용된 SU계 제초제들의 기준량에 대한 나주, 논산, 김제 지역계통의 건물 중 50% 억제 제초제 농도인 $GR_{50}$은 감수성계통(청도) 보다 각각 $8{\sim}33$배, $8{\sim}30$배, $7{\sim}32$배 높게 나타났다. 그러나 김해 채집계통의 $GR_{50}$은 감수성 채집계통에 비해 $4{\sim}13$배 높게 나타나 중간정도의 저항성을 보였다. 나주, 논산, 김제에 대한 ALS 50% 억제 제초제 농도인 $I_{50}$은 감수성 채집계통에 비해 각각 $25{\sim}66$배, $9{\sim}26$배, $10{\sim}24$배 높게 나타났다. 그러나 김해 채집계통의 91%은 감수성 채집계통에 비해 $4{\sim}9$배 높게 나타났다.

• Weed & Turfgrass Science
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• 제6권1호
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• pp.28-31
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• 2017

The mutation rate of proline in the position 197 (Pro197) in acetohydroxy acid synthase (AHAS) is highest among sulfonylurea (SU) herbicide-resistance mutants. Therefore, it is significant to investigate the resistance mechanism for the mutation and to develop the herbicides specific to the mutants. SU herbicide resistance mechanism of the mutants, 197Ser, 197Thr and 197Ala, in AHAS were targeted for designing new SU-herbicide. We did molecular dynamics (MD) simulation for understanding SU herbicide-resistance mechanisms of AHAS mutants and designed new herbicides with docking and MD evaluations. We have found that mutation to 197Ala and 197Ser enlarged the entrance of the active site, while 197Thr contracted. Map of the root mean square derivation (RMSD) and radius gyrations (Rg) revealed the domain indicating the conformations for herbicide resistant. Based on the enlarging-contracting mechanism of active site entrance, we designed new herbicides with substitution at the heterocyclic moiety of a SU herbicide for the complementary binding to the changed active site entrances of mutants, and designed new herbicides. We confirmed that our screened new herbicides bonded to both AHAS wild type and mutants with higher affinity, showing more stable binding conformation than the existing herbicides.

• 농약과학회지
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• 제9권3호
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• pp.205-213
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• 2005

본 연구는 국내 논에 광범위하게 사용되고 있는 설포닐우레아계 제초제에 대한 몇몇 수생식물의 반응과, 생물다양성 보존위하여 제초제 특히 sulfonylurea계 제초제가 농업환경에 미치는 영향평가를 위한 지표식물의 가능성을 구명하고자 실시하였다. sulfonylurea계 제초제와 부타크르를 각각 다년간 사용하고 있는 전라남도와 강원도의 논 생태계에서 수생식물의 분포를 조사한 결과 강원도에서 훨씬 다양한 수생식물이 확인되었다. 수생식물인 물옥잠, 네가래, 그리고 생이가래는 비설포닐우레아계 제초제인 butachlor와 molinate 보다 bensulfuron-methyl과 pyrazosulfuron-ethy에 훨씬 민감하게 반응하였다. 물옥잠, 네가래, 그리고 생이가래의 건물중을 50%억제하는 $GR_{50}$ 값은 bensulfuron-methyl과 pyrazosulfuron-ethyl이 butachlor와 molinate 보다 훨씬 낮았다. 논으로부터 유출된 제초제에 대하여 네가래의 생육은 심하게 억제되었다. 그리고 네가래에 대한 bensulfuron-methyl과 pyrazosulfuron-ethy의 $I_{50}$ 수치는 각각 5.6 및 2.1nM을 보였다.

• 농약과학회지
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• 제12권1호
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• pp.1-8
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• 2008

최근 한국 논에서는 1989년부터 pyrazosulfuron/molinate 및 bensulfuron/molinate와 같은 "일발처리제"의 광범위한 사용으로 설포닐우레아(SU)계 제초제 저항성 잡초들이 급증하고 있다. 2008년 현재까지 확인된 SU계 제초제 저항성 잡초들은 일년생 잡초 7초종과 다년생 잡초 3초종이 각각 확인되었다. 현재까지 개발 및 사용되어온 SU계 제초제들과 화본과 전용 제초제들이 혼합된 "일발처리제"로부터 제초제 저항성 잡초 방제를 위주로 한 새로운 제초제 개발이 요구된다. 최근 한국과 농업적 환경이 유사한 일본은 제초제 저항성 잡초를 방제하기 위한 시스템으로 제초제 개발이 급변하고 있다. 따라서 한국에서도 제초제 전문약제들이 혼합된 3종 이상의 새로운 "일발처리제" 개발로 전환되어 져야 한다. Benzobicyclone, bromobutide, cafentrazone, pyrimisulfam은 SU계 제초제 저항성 잡초에 효과적인 제초제들이다. 그러나 이들 제초제 전문 약제들에 대한 제초제 저항성 잡초 초종별 반응은 서로 다르게 나타났는데, bromobutide와 cafentrazone은 각각 사초과와 광엽잡초에 효과적이나 benzobicyclone과 pyrimisulfam은 사초과와 광엽잡초에 모두 효과적이다.