• Bulletin of the Korean Chemical Society
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• 제23권7호
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• pp.929-930
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• 2002

• Toxicological Research
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• 제11권1호
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• pp.51-55
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• 1995

The present experiment was carried out to investigate whether X and Y chromosome dissociation in the primary spermatocytes of mice can be used as an in vivo assaying system that detect environmental mutagens. For this purpose, alkylating agents (EMS, MMS and MMC), which are strong mutagens, were administered to ICR male mice 12-15 weeks old. The mean frequencies of previously dissociated X-Y chromosomes and autosomes of the control group were 7.34-7.45% and 0.92-1.04%, respectively. The frequencies of X-Y dissociation in the mutagen-treated groups with 10.0 mM EMS and 5.0 mM MMS were about 3.3-4.6 times higher than that in the control group, but there were no significant differences in dissociation of autosomes in both the control and the mutagen-treated groups. These results suggest that X-Y dissociation in the primary spermatocytes of mice can be used as an in vivo short-term assaying system for environmental mutagens.

• Bulletin of the Korean Chemical Society
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• 제24권6호
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• pp.731-732
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• 2003

Mutagen X (MX), 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone is one of the most potent directing acting mutagen ever tested in SAL TA100 assay. Although MX analogues have been synthesized, tested for mutagenicity and modeled by structure-activity relationship (SAR) methods, the mechanism of interaction of these compounds with DNA to produce their remarkable mutagenic potency remains unresolved. MX exists as an equilibrium mixture of both ring and open form in water. This equilibrium is very fast for Ames test. Because the mixture is not separable by experimental methods, it is not clear which one is really responsible for the observed mutagenicity. There have been many debates that which one is really responsible for the observed mutagenicity. We used ab initio methods for the MX analogues. It seems both ring and open form could react with DNA bases as electrophiles. However, every open form has consistently lower LUMO energy than corresponding ring form. It is reasonable to assume that the major reaction will go through via open form for MX analogues. This suggest that the open form is more likely really mutagenic.

• Molecular & Cellular Toxicology
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• 제1권1호
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• pp.46-51
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• 2005

Mutagen X (MX) exists in our drinking water as the bi-products of chlorine disinfection. Being one of the most potent mutagen, it attracted much attention from many researchers. MX and its analogs are tested and modeled by quantitative structure activity relationship (QSAR) methods. As a result, factors affecting this class of compounds have been found to be steric and electrostatic effects. We tried to collect all the data available from the literature. The quantitative structure-activity relationship of a set of 29 MX was analyzed using Molecular Field Analysis (MFA) and Receptor Surface Analysis (RSA). The best models gave $q^{2}=0.918,\;r^{2}=0.949$ for MFA and $q^{2}=0.893,\;r^{2}=0.954$ for RSA. The models indicate that an electronegative group at C6 position of the furanone ring increases mutagenicity.

• 한국작물학회지
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• 제36권1호
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• pp.74-78
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• 1991

밀 약배양에 있어서 Callus 유기, 식물체분화 및 분화식물체의 염색체 변이에 미치는 돌연변이 유기제의 처리 효과를 검토코자 감수 분열기 1 핵기 이삭에 X-ray는 4수준( 100, 200, 500, 1,000 rad) Ethyle Methane Sulphonate 는 3수준 ( 0.1, 0.2, 0.3M)으로 각각 처리하여 $C_{l7}$배지에서 callus를 유기시키고 1/2 MS 배지에서 식물체를 분화시켰다. 그 결과 callus 유기는 억제되었으나 식물체분화는 다소 높았으며 특히 약치상 후 61～80일째 장기치상된 약의 callus에서 식물체분화율이 높았다. 분화식물체의 염색체 변이는 반수체(n=3 x=21) 발생율이 증가되었고 n=20, n=21개의 염색체를 갖는 이수체가 발생되어 염색체 변이가 컸다.다.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1525-1530
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• 2004

Mutagen X (MX) exists in our drinking water as the bi-products of chlorine disinfection. Being one of the most potent mutagen, it attracted much attention from many researchers. MX and its analogs are synthesized and modeled by quantitative structure activity relationship (QSAR) methods. As a result, factors affecting this class of compounds have been found to be steric and electrostatic effects. We tried to collect all the data available from the literature. With both CoMFA and CoMSIA various combinations of physiochemical parameters were systematically studied to produce reasonable 3-dimensional models. The best model for CoMFA gave $q^2$ = 0.90 and $r^2$ = 0.97, while for CoMSIA $q^2$ = 0.85 and $r^2$ = 0.94. So the models seem to be reasonable. Unlike previous result of CoMFA, in our case steric parameter alone gave the best statistics. Although the steric contribution was found to be the most important in both CoMFA and CoMSIA, steric parameter along with electrostatic parameter produced slightly better model in CoMSIA. Overall, steric contribution is clearly the most important single factor. However, when we compare chlorine and bromine substitution, chlorine substitution can be more mutagenic. This indicates that other factors such as electrostatic effect also influence the mutagenicity. From the contour maps, steric contribution seems to be focused on rather small area near C6 substituent of the furanone ring, rather than C3 substituent. Therefore the locality of steric contribution can play a significant role in mutagenicity.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2003년도 추계학술대회
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• pp.136-136
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• 2003

• Bulletin of the Korean Chemical Society
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• 제26권1호
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• pp.85-90
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• 2005

MX and its analogs are synthesized and modeled by quantitative structure activity relationship (QSAR) study including comparative molecular field analysis (CoMFA). As a result, factors affecting this class of compounds have been found to be steric and electrostatic effects. Because hologram quantitative structure activity relationship (HQSAR) technique is based on the 2-dimensional descriptors, this is free of ambiguity of conformational selection and molecular alignment. In this study we tried to include all the data available from the literature, and modeled with the HQSAR technique. Among the parameters affecting fragmentation, connectivity was the most important one for the whole compounds, giving good statistics. Considering additional parameters such as bond specification only slightly improved the model. Therefore connectivity has been found to be the most appropriate to explain the mutagenicity for this class of compounds.

• 한국환경과학회지
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• 제7권5호
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• pp.599-605
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• 1998

The purpose of this work was to examine whether X-Y chromosome dissociation in the primary spermatocytes of mice could be used as an in vivo short-term assaying system that detect environmental mutagens. Four alkylating agents(EMS, MMS, MMC and MNNG) which were known as strong mutagens were administered to BALB/c male mice 3-4 months old. In the control group, the mean frequencies of previously dissociated X and Y chromosomes and autosomes were 7.17% and 2.12%, respectively. Compared to the control group, mutagen-treated groups have no significant differences in dissociation rate of autosomes, while these poops were about 1.2-2.5 times higher in the frequencies of X-Y dissociation. Generally, X-Y dissociation frequency increased consistently with the concentration of mutagens whereas the tendency of autosome dissociation frequency was variable among several mutagens. These results suggest that X-Y dissociation in the primary spermatocytes of mice is applicable as an vivo short-term assaying system for environmental mutagens. There were significantly distinct increase in dissociation of X-Y chromosome in both the hybrid and parents but the X-Y previous dissociation of hybrid appeared higher frequency than BALB /c and wild mice. These results indicate that the factor related to binding X-Y chromosome is specific to strains.

• 한국환경성돌연변이발암원학회지
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• 제7권2호
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• pp.103-111
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• 1987

The effects of LET (linear energy transfer) of radiation on the induction of somatic chromosome mutations or gene mutations of Drosophila melanogaster were studied. For detecting somatic chromosome mutations and gene mutations, Drosophila wing spot system and eye-color spot system were used, respectively. The frequencies of somatic chromosome mutations or gene mutations induced after third instar larval treatment with 23 MeV neutrons, thermal neutrons, X-rays were examined. From these data, the RBE(relative biological effectiveness) values of 23 MeV neutrons relative to X-rays for induction of somatic chromosome mutations or gene mutations were calculated. The present results suggest that high LET radiations are efficient than X-ray in producing not only somatic chromosome mutations but also gene mutations.