Radiosensitizers, anticancer activity

The related /V-oxide (77) demonstrates pharmaceutical activity without structural modification, being used as a radiosensitizer to promote tumour regression during radiation therapy (B-80MI20904). Similarly, 4-acetamidopyridine 1-oxide (78) has been described as a neuromuscular stimulant (80MI20905). A carboxylic acid derivative (79) demonstrating anticancer activity independent of any radiation treatment has recently been reported (81JMC1181). 

Recently Clarke et al. have advanced the proposal that antitumor RudDammine complexes may excert their action by redox cycling in the presence of oxygen and a reducing agent with formation of active oxygen species which cleave DNA. The most prominent member of the metal group is cis-DDP. Evidence for electron transfer is provided by electrochemical behavior , radiosensitization" and nephrotoxicity s 2-74, Anticancer activity is displayed by a number of other metals and metalloids in compound form s -- . The possibility exists that the ultimate active forms of the various metals may be the DNA complexes, for example, with copper s and ruthenium . ET and oxy radical formation are known to occur with enzymes that contain copper s . 

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