Antimicrobial N-methylpyridinium salts related to the xestamines from the Caribbean sponge Calyx podatypa.

Two antimicrobial fractions were obtained from the sponge Calyx podatypa from the Bahamas. The less polar fraction contained the known compounds xestamines A [1] and B [2] and three new metabolites called xestamines D [3], E [4], and F [5]. The more polar fraction consisted of a mixture of xestamines G [6] and H [7].