Palmyrolide A an Unusually Stabilized Neuroactive Macrolide from Palmyra Atoll Cyanobacteria

摘要

Palmyrolide A (1) is a new neuroactive macrolide isolated from a marine cyanobacterial assemblage composed of Leptolyngbya cf. 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 µM), palmyrolide A (1) showed relatively potent sodium channel blocking activity in neuro-2a cells (IC50=5.2 µM), without appreciable cytotoxicity.