C 60 /C 70 mixture reacts with hydrazine hydrate catalysed by tetrabutylammonium bromide (TBAB) in the presence of air to afford fullerene hydrazine derivatives C 60 (OH) n(NHNH 2) n and C 70 (OH) n(NHNH 2) n,whi...C 60 /C 70 mixture reacts with hydrazine hydrate catalysed by tetrabutylammonium bromide (TBAB) in the presence of air to afford fullerene hydrazine derivatives C 60 (OH) n(NHNH 2) n and C 70 (OH) n(NHNH 2) n,which are characterized by means of MS and FTIR.A possible reaction mechanism is discussed.展开更多
Inhibition of DNA repair is one proposed mechanism for the co-mutagenicity/co-carcinogenicity of arsenic.This review summarizes the current literature on the effects of arsenic compounds on nucleotide excision repair(...Inhibition of DNA repair is one proposed mechanism for the co-mutagenicity/co-carcinogenicity of arsenic.This review summarizes the current literature on the effects of arsenic compounds on nucleotide excision repair(NER).Several possible mechanisms for the observed NER inhibition have been proposed.Modulation of the expression of NER proteins has been considered to be one possibility of impairing the NER process.However,data on the effects of arsenic on the expression of NER proteins remain inconsistent.It is more likely that arsenic inhibits the induction of accessory or other key proteins involved in cellular control of DNA repair pathways,such as p53.For example,arsenic affects p53 phosphorylation and p53 DNA binding activity,which could regulate NER through transcriptional activation of downstream NER genes.Although it is important to study possible direct inactivation of NER proteins by arsenic binding,indirect inactivation of proteins having thiol residues critical to their function or zinc finger proteins cannot be negated.For example,nitric oxide(NO) induced in arsenic-treated cells serves as a specific inhibitor of NER,possibly through NO-induced S-nitrosylation of proteins related to DNA repair.Poly(ADP-ribose) polymerase-1,a zinc finger protein implicated in both NER and base excision repair(BER),deserves special attention because of its involvement in NO production and its broad range of protein substrates including many repair enzymes.展开更多
文摘C 60 /C 70 mixture reacts with hydrazine hydrate catalysed by tetrabutylammonium bromide (TBAB) in the presence of air to afford fullerene hydrazine derivatives C 60 (OH) n(NHNH 2) n and C 70 (OH) n(NHNH 2) n,which are characterized by means of MS and FTIR.A possible reaction mechanism is discussed.
基金supported by the Canadian Institutes of Health Researchthe Natural Sciences and Engineering Research Council of Canada+2 种基金the Canada Research Chairs ProgramAlberta Health and Wellness,Alberta Cancer FoundationAlberta Innovates Energy and Environment Solutions
文摘Inhibition of DNA repair is one proposed mechanism for the co-mutagenicity/co-carcinogenicity of arsenic.This review summarizes the current literature on the effects of arsenic compounds on nucleotide excision repair(NER).Several possible mechanisms for the observed NER inhibition have been proposed.Modulation of the expression of NER proteins has been considered to be one possibility of impairing the NER process.However,data on the effects of arsenic on the expression of NER proteins remain inconsistent.It is more likely that arsenic inhibits the induction of accessory or other key proteins involved in cellular control of DNA repair pathways,such as p53.For example,arsenic affects p53 phosphorylation and p53 DNA binding activity,which could regulate NER through transcriptional activation of downstream NER genes.Although it is important to study possible direct inactivation of NER proteins by arsenic binding,indirect inactivation of proteins having thiol residues critical to their function or zinc finger proteins cannot be negated.For example,nitric oxide(NO) induced in arsenic-treated cells serves as a specific inhibitor of NER,possibly through NO-induced S-nitrosylation of proteins related to DNA repair.Poly(ADP-ribose) polymerase-1,a zinc finger protein implicated in both NER and base excision repair(BER),deserves special attention because of its involvement in NO production and its broad range of protein substrates including many repair enzymes.
