Bioactive enediynes

Unlike the other naturally occurring enediyne molecnles, neocarzinostatin chromophore (30) is activated into an enyne-butatriene. This unusual cumulene 57 undergoes a cyclization analogous to the Bergman cyclization, proposed concurrently by Myers and Saito. This cyclization, now referred to as Myers-Saito cyclization, produces the diradical 58 that can abstract hydrogen atoms from DNA. Thus, neocarzinostatin s bioactivity is remarkably similar to calichaemicin (Figure 4.14). 

Synthetic studies on structurally novel bioactive nine-membered cyclic enediynes with an annulated oxirane fragment 04YGK226. 

The Enediyne Polyketide Synthase (PKSE) Evolutionary Origins and a Means by Which to Find New Bioactive... 

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