Antifungal Amphidinol 18 and Its 7-Sulfate Derivative from the Marine Dinoflagellate Amphidinium carterae

Two new polyketides of the amphidinol family, amphidinol 18 (wAM18, 1) and its corresponding 7-sulfate derivative (AM19, 2), have been isolated from the MeOH extract of the dinoflagellate Amphidinium carterae. Structure elucidation of the two polyoxygenated molecules has been accomplished by extensive use of spectroscopic and spectrometric techniques. AM18 exhibited antifungal activity against Candida albicans at 9 mu g/mL.