Diynes naphthalene ring

When the double bond of the 3-ene-l,5-diyne system is part of a benzene or a naphthalene ring, a lowered activity resulted, in agreement with the lower activity of benzo-fused enediynes already cited in Section 19.3.2. Finally, the activity both in vitro (human carcinoma KB cells) and in vivo (mice inoculated with murine P338 leukemia) of 87-89 was tested. Interestingly, while the phenyl carbamates have no detectable in vitro activity against plasmid DNA and were less cytotoxic in vitro than 87-89, an opposite behavior was observed in vivo. Thus the phenyl carbamates showed an interesting activity, while the sulfones showed little or no activity, probably due to the fact that they are quite unstable and they are not able to reach tumor cells before cycloaromatization begins. 

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