• Journal of Plant Biology
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• 제19권1호
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• pp.14-18
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• 1976

Inhibition of flowering in Lemna perpusilla 6746 by 30 mM sucrose was reversed by the addition of acetylcholine (>$10^{-4}M) supplemented with 10^{-4}M$ ascorbic acid to 1/10-strength Hunter's growth medium. The reversible effect of acetylcholine was found to be greater at early stages of flowering than in the later period. Promotive effects of both acetylcholine ($10^{-3}M) and eserine(10^{-5}M$) on flowering in the short-day plant under various photoperiodic conditions were studied. It was indicated that the application decreased length of the critical dark period for the floral induction, and it was also shown that the endogenous status of acetylcholine was involved in the floral response which had a correlation with phytochrome. Interruption of inductive dark periods by red irradiation (1min) immediately followed by far-red light (1 min) completely inhibited flowering, while the addition of acetylcholine and eserine to the medium under the same condition slightly promoted flowering, indicating possible involvement of phytochrome system in acetylcholine activity for photoperiodic sensitivity of floral response in Lemna perpusilla 6746.

• 농약과학회지
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• 제11권3호
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• pp.171-178
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• 2007

소나무 수피와 잣나무 수피를 먹이로 사육한 북방수염하늘소(M. saltuarius)의 종령유충의 소화액을 추출하여 4가지 기질(${\alpha}$-naphthyl acetate, ${\beta}$-naphthyl acetate, ${\alpha}$-naphthyl butyrate, ${\beta}$-naphthyl stearate)에 대한 에스테라제(esterase) 활성도 변화를 조사하였다. ${\alpha}$-naphthyl acetate를 기질로 하여 조사한 결과 Est7이 잣나무수피를 먹인 유충에서 강하게 활성화되었다. 또한, ${\beta}$-naphthyl acetate와 ${\alpha}$-naphthyl butyrate 기질을 사용한 경우에도 Est6과 Est7이 잣나무수피를 먹인 유충에서 강한 활성이 관찰 되었다. 그러나 ${\beta}$-naphthyl stearate에서 활성화 되는 에스테라제는 관찰할 수 없었다. 추출한 소화액에 카바메이트계와 유기인계 약제를 처리한 경우 Est7을 포함하여 Est3과 Est6이 강하게 저해되는 것으로 나타났다. 또한, eserine을 처리한 경우 Est4, Est6, Est7에서 강한 활성저해가 관찰되었다. Methoprene, bornyl acetate, linal, cineol, citral을 소화액에 첨가한 경우 에스테라제의 활성저해는 관찰되지 않았으나 이상의 결과는 in vitro에서 실시된 실험으로 추후 in vivo에서 재검증이 필요 할 것이다.

• BMB Reports
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• 제43권8호
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• pp.573-578
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• 2010

Several organophosphorus (OP) insecticides can selectively kill the silkworm maggot, Exorista sorbillans (Es) (Diptera: Tachinidae), while not obviously affecting the host (Bombyx mori) larvae, but the mechanism is not yet clear. In this study, the cDNA encoding an acetylcholinesterase (AChE) from the field Es was isolated. One point mutation (Gly353Ala) was identified. The Es-353G AChE and Es-353A AChE were expressed in baculovirus-insect cell system, respectively. The inhibition results showed that for eserine and Chlorpyrifos, Es-353A AChE was significantly less sensitive than Es-353G AChE. Meanwhile, comparison of the I50 values of eserine, dichlorvos, Chlorpyrifos and omethoate of recombinant Es AChEs with its host (Bombyx mori) AChEs indicated that, both Es AChEs are more sensitive than B. mori AChEs. The results give an insight of the mechanism that some OP insecticides can selectively kills Es while without distinct effect on its host, B. mori.

• 농약과학회지
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• 제11권3호
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• pp.179-185
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• 2007

북방수염하늘소(M. saltuarius) 성충 장(gut)내에 존재하는 소화액에 대한 에스테라제(esterase)의 활성 변화를 in vitro에서 조사하였다. ${\alpha}$-naphthyl acetate와 ${\alpha}$-naphthyl butyrate 기질을 이용한 실험에서는 4개의 밴드가 관찰되었다. Carbofuran과 methomyl을 비교 처리한 결과 methomyl에서 강한 효소활성 저해가 관찰되었다. 특히 Est1은 carbofuran과 methomyl에 의해 모두 저해되는 것으로 나타났다. Chlorpyrifos, methidation, phenthoate를 비교 처리한 결과 chlorpyrifos에 의해 모든 밴드들이 저해되는 것을 볼 수 있었다. 특히 Est1은 chlorpyrifos에 의해 효소활성이 완전히 저해되었고, methidation 처리시 약 70% 정도의 효소활성이 저해 되었다. Eserine을 처리한 결과 Est1은 약 70% 정도의 활성 저해를, Est2, Est3, Est4에서는 미미한 효소활성 저해가 나타났다. ${\alpha}$-pinene에서는 뚜렷한 효소활성 저해는 관찰할 수 없었으나 bornyl acetate와 camphor에서는 미미한 효소활성 저해가 관찰되었다.

• Parasites, Hosts and Diseases
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• 제31권4호
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• pp.321-330
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• 1993

Fibricola seoulensis의 피낭유충을 흰쥐에게 경구 감염시켜 3, 4, 5. 6, 7일 별로 부 검 회수하여 생리 식염수로 씻은 후, 10% neutral formalin buffer에 고정 후 세척하였다. Acetylcholinesterase 염색은 기질로 acetylthiocholine iodide를 사용한 효소조직화학적 방법으로 피낭유충과 여러 성장 과정에 있는 충체의 신경계 분포 발달과정을 관찰하고 억제제로는 eserine, iso-OMPA, BW284C51를 사용하였다. 신경계는 피낭유충과 성충의 전반부 부위의 인두와 구흡반과 후반부의 배설 신경총을 연결하는 3쌍의 종주신경간과 그들을 연결하는 횡신경 연합과 환상신경 연합으로 구성되어 있으며, 다수의 환상신경 연합은 충체표면 가까이에 위치한 종주신경간과도 연결되어 있다. 충체 발달의 모든 단계에서 구흡반 및 복흡반, 인두, 신경계에 acetylcholinesterase와 nonspeciaccholinesterase의 염색반응이 관찰되었다. F. seoulensis의 acetylcholinesterase 동위효소 유형은 분자량 69 kDa. 132 kDa의 2개의 분획이 분리되었으며 그 중 69 kDa 분획대가 주분획을 이루었다.

• 한국연초학회지
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• 제21권1호
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• pp.49-56
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• 1999

Classification of esterase isozymes of the apterous green peach aphids (Myzus persicae Sulzer) collected in tobacco fields were investigated by the native polyacrylamide gel electrophoresis (PAGE). A total of twelve esterase bands were identified in adult apterous aphid, and the difference of enzyme band activity in the clones was observed at the first and second bands group. Esterases of green peach aphids reacted with specific substrate were more stained $\alpha$-naphthyl acetate than $\alpha$-naphthyl propionate, and $\alpha$-naphthyl acetate more than $\beta$-naphthyl acetate. Twelve esterases on the basis of inhibition by the three types of inhibitors (organophosphates: 2.5$\times$10$^{-3}$ M paraoxon, 4$\times$10$^{-3}$ M DFP; eserine sulfate : 2$\times$10$^{-3}$ M eserin; sulfhydryl reagents: 2$\times$10$^{-3}$ M p-HMB) were classified into three class, namely, cholinesterase (ChE) I, II, carboxylesterase (CE) and arylesterase (ArE), and these classes contained 3, 4, 3 and 2 isozymes, respectively.

• Toxicological Research
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• 제22권1호
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• pp.1-8
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• 2006

The primary metabolism of pyribenzoxim was studied in rat liver microsomes in order to identify the cytochrome P450 (CYP) isoform(s) and esterases involved in the metabolism of pyribenzoxim. Chemical inhibition using CYP isoform-selective inhibitors such as ${\alpha}$-naphthoflavone, tolbutamide, quinine, chlorzoxazone, troleandomycin, and undecynoic acid indicated that CYP1A and CYP2D are responsible for the oxidative metabolism of pyribenzoxim. And inhibitory studies using eserine, bis-nitrophenol phosphate, dibucaine, and mercuric chloride indicated pyribenzoxim hydrolysis involved in microsomal carboxylesterases containing an SH group (cysteine) at the active center.

• 한국연초학회지
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• 제20권1호
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• pp.80-86
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• 1998

Changes in activity and classification of esterase isozymes during the tire cycle or Plodia inteipunctella (Hiibner) were investigated by the native polyacrylamide gel electrophoresis. The stage specificity in esterase activity and isozyme pattern was observed throughout the larvalpupal-adult transformation. The activity esterase was highest at the 3-day old adult stage, and the lowest level at the prepupal stage. A total of 12 esterase bands were identified throughout the development, and the bands showing high enzyme activity was observed in the middle part of gel. Twelve esterases on the basis of inhibition by the three types of inhibitors (organophosphates, eserine sulfate and sulfhydryl reagents) were classified into three class, namely, carboxylesterase (CE), arylesterase (ArE) and cholinesterase (ChE), and these classes contained 7, 3 and 2 isozymes, respectively.

• 한국동물학회지
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• 제39권2호
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• pp.190-197
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• 1996

The optimal conditions and substrate specificity of whole body esterase (EST) activity, effects of inhibitors (Eserine, Paraoxon, p-HMB, DDVP, DFP) on the enzyme, and ontogenv of the isozymes were determined in Lucilio ilfustris Meisen. The optimal temperature was $45^{\circ}C$ regardless of kind of reacted substrate, $\alpha-naphthyl$ acetate $(\alpha-Nal,$ a.naphthvl butylate $(\alpha-N),$ and Pnaphthyl acetate $(\beta-Na),$ but the optimal pH showed some regioselectivitv to naphthvl group of the esters; PH 7.0 for Iform, pH 7.5 for a-form. The maximum reaction rate was recorded at about 2.5 $\times$ 10's M of PNa and etNa, but 1.0 $\times$ 10'S M of $\alpha-Nb.$ Among the five EST inhibitors tested, DDVP was the most powerful. However, distinction of the relative specificity of inhibitors between three body parts, head, thorax, and abdomen, was shouts, representing differences in the distribution and activity of isozvmes. Of 12 carboxyl-esterases (CE), 8 cholinesterases (ChE) and 2 arvlesterases (ArE) identified based on their inhibitor specificity throughout the development, two larval and prepupal stage specific ChEs, no pupal specific, and 2 CEs.2ChEs. and one ArE adult specific isozvmes were confirmed.

• Mycobiology
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• 제43권2호
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• pp.137-149
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• 2015

In the search for novel potent fungi-derived bioactive compounds for bioinsecticide applications, crude ethyl acetate culture filtrate extracts from 110 mangrove fungal endophytes were screened for their toxicity. Toxicity tests of all extracts against brine shrimp (Artemia salina) larvae were performed. The extracts with the highest toxicity were further examined for insecticidal activity against Spodoptera litura larvae and acetylcholinesterase (AChE) inhibition activity. The results showed that the extracts of five isolates exhibited the highest toxicity to brine shrimp at 50% lethal concentration ($LC_{50}$) values of 7.45 to 10.24 ppm. These five fungal isolates that obtained from Rhizophora mucronata were identified based on sequence data analysis of the internal transcribed spacer region of rDNA as Aspergillus oryzae (strain BPPTCC 6036), Emericella nidulans (strains BPPTCC 6035 and BPPTCC 6038), A. tamarii (strain BPPTCC 6037), and A. versicolor (strain BPPTCC 6039). The mean percentage of S. litura larval mortality following topical application of the five extracts ranged from 16.7% to 43.3%. In the AChE inhibition assay, the inhibition rates of the five extracts ranged from 40.7% to 48.9%, while eserine (positive control) had an inhibition rate of 96.8%, at a concentration of 100 ppm. The extracts used were crude extracts, so their potential as sources of AChE inhibition compounds makes them likely candidates as neurotoxins. The high-performance liquid chromatography profiles of the five extracts differed, indicating variations in their chemical constituents. This study highlights the potential of culture filtrate ethyl acetate extracts of mangrove fungal endophytes as a source of new potential bioactive compounds for bioinsecticide applications.