Detail of "68498-25-9"

Reference

Assessment of mutagenic efficiency of two carcinogen-modified nucleosides, 1,N6-ethenodeoxyadenosine and O4-methyldeoxythymidine, using polymerases of varying fidelity

Assessment of mutagenic efficiency of two carcinogen-modified nucleosides, 1,N6-ethenodeoxyadenosine and O4-methyldeoxythymidine, using polymerases of varying fidelity. Singer, B.; Abbott, L. G.; Spengler, S. J. (Lab. Chem. Biodyn., Univ. California, Berkeley, CA 94720, USA). Carcinogenesis (London), 5(9), 1165-71 (English) 1984. CODEN: CRNGDP. ISSN: 0143-3334. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) Terminal deoxynucleotidyl transferase (TdT) [9027-67-2] was used to prep. copolymers of dA [958-09-8] and 1,N6-ethenodeoxyadenosine (edA) [68498-25-9]. When used as templates for Escherichia coli DNA polymerase I (Pol I) [9012-90-2] and compared with poly (dA) [25191-20-2], normal dTTP [365-08-2] incorporation was not significantly affected by the presence of 7% edA. DGTP [2564-35-4] misincorporation was only slightly increased and occurred about once for every 500 edA residues. The error-prone polymerase from avian myeloblastosis virus (AMV reverse transcriptase [9068-38-6]) increased this error rate 5- to 20-fold to a max. of 1 dG [961-07-9]/25 edA. No dCTP misincorporation was detected with either polymerase. In transcription with E. coli DNA-dependent RNA polymerase [9014-24-8], no errors were revealed by nearest neighbor anal. Poly (dA) treated with chloroacetaldehyde [107-20-0] under conditions producing the same proportion of edA (without the hydrated form) as the synthesized template behaved in the same manner with a similar low level of misincorporation of dG. Such treatment of alternating poly d(A-T) [26966-61-0] caused structural changes indicative of crosslinks but did not alter its template properties. Increasing the amt. of edA in either synthesized or modified polymers greatly decreased the template activity without increasing the error rate. It is suggested that edA generally does not prevent dT incorporation but behaves as a bulky lesion which is bypassed. In contrast to the low mutagenic efficiency of edA, O4-methyldeoxythymidine (m4dT) [50591-13-4], in copolymers with dA, directed the misincorporation of 1 dG/12 m4dT with Pol I and 1 dG/3 m4dT with reverse transcriptase. Nearest neighbor anal. of transcripts showed the incorporation of 1 dG/12 m4dT. These data are in agreement with the previous reported mutagenicity of m4dT in alternating poly d(A-T, m4T).

Evaluation of the mutagenicity of 1,N6-ethenoadenine- and 3,N4-ethenocytosine-nucleosides in Salmonella typhimurium

Evaluation of the mutagenicity of 1,N6-ethenoadenine- and 3,N4-ethenocytosine-nucleosides in Salmonella typhimurium. Negishi, K.; Oohara, K.; Urushidani, H.; Ohara, Y.; Hayatsu, H. (Fac. Pharm. Sci., Okayama Univ., Okayama, Japan). IARC Sci. Publ., 70(Role Cyclic Nucleic Acid Adducts Carcinog. Mutagen.), 293-7 (English) 1986. CODEN: IARCCD. 68498-25-9 and 39007-52-8 are cas registry numbers of chemicals which are used as reagents here. ISSN: 0300-5038. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) To provide supporting evidence for the hypothetical involvement of etheno deriv. formation in DNA in chloroacetaldehyde-mediated mutagenesis, etheno nucleosides were examd. for their direct-acting mutagenicity in Salmonella typhimurium strain TA100. 1,N6-Ethenoadenosine [39007-51-7], 1,N6-ethenodeoxyadenosine [68498-25-9], 3,N4-ethenocytidine [39007-52-8], and 3,N4-ethenodeoxycytidine (I) [68498-26-0] lacked mutagenicity in this test system. The 3,N4-ethenocytosine nucleosides prepd. synthetically or obtained from com. sources can give false pos. mutagenicity due to mutagenic contaminants. .