Palmyrolide A, an Unusually Stabilized Neuroactive Macrolide from Palmyra Atoll Cyanobacteria

Palmyrolide A (1) is a new neuroactive macrolide isolated from a marine cyanobacterial assemblage composed of Leptolyngbya cl and Oscillatoria spp collected from Palmyra Atoll It features a rare N-methyl enamide and an Intriguing t-butyl branch, the latter renders the adjacent lactone ester bond resistant to hydrolysis. Consistent with its significant suppression of calcium influx in cerebrocortical neurons (IC50 = 3.70 mu M), palmyrolide A (1) showed a relatively potent sodium channel blocking activity in neuro-2a cells (IC50 = 5.2 mu m). without appreciable cytotoxicity