No abstract

The total synthesis of a novel pyranonaphthoquinone (2) having Cdc25A phosphatase inhibitory activity is achieved. The key step in this synthetic pathway is the intramolecular Michael addition for construction of the pyran ring system. The inhibitory activity of several derivatives, readily obtained from synthetic intermediates of 2, is assessed. The resulting data indicates that the pyran ring moiety is not a crucial factor for the activity.

No abstract

No abstract

2005Benzopyran derivatives R 0350The Synthesis and Biological Activity of Pyranonaphthoquinone Derivatives from Streptomyces sp. and Their Related Substances. -The total synthesis of the novel pyranonaphthoquinone (XV) is achieved through two synthetic pathways. The first one involves an intramolecular Michael addition as a key step to construct the pyran ring system. Alternatively, to accomplish the efficient synthesis of (XV), the pyran ring moiety is constructed in the final stage, starting from allyl alcohol (X). Two intermediates obtained in the first route as well as quinone (XIV) and pyranonaphthoquinone (XV) are evaluated as inhibitors of the Cdc25A phosphatase. Quinone (XIV) reveals a stronger activity than (XV) and the other derivatives, suggesting that the pyran ring system is not necessary for inhibitory activity. -(SHIMBASHI, A.; TSUCHIYA, A.; IMOTO, M.; NISHIYAMA*, S.; Bull. Chem.