220231-09-4Relevant articles and documents
Total syntheses of ningalin A, lamellarin O, lukianol A, and permethyl storniamide A utilizing heterocyclic azadiene Diels - Alder reactions
Boger, Dale L.,Boyce, Christopher W.,Labroli, Marc A.,Sehon, Clark A.,Jin, Qing
, p. 54 - 62 (2007/10/03)
Concise, efficient total syntheses of ningalin A (1), lamellarin O (2), lukianol A (3), and permethyl storniamide A (5) are detailed on the basis of a common heterocyclic azadiene Diels-Alder strategy (1,2,4,5-tetrazine → 1,2-diazine → pyrrole) ideally suited for construction of the densely functionalized pyrrole cores found in the three classes of marine natural products. Examination of the natural products and a number of synthetic intermediates revealed that some including lamellarin O (2) and lukianol A (3) exhibit modest cytotoxic activity against both wild-type and multidrug- resistant tumor cell lines. Fundamentally more important, a new class of agents including permethyl storniamide A (5) and its precursor 30, which lack inherent cytotoxic activity, are disclosed which reverse the multidrug- resistant (MDR) phenotype, resensitizing a human colon cancer cell line (HCT116/VM46) to vinblastine and doxorubicin at lower doses than the prototypical agent verapamil.