Acetate labeling patterns of dinoflagellate polyketides, amphidinols 2, 3 and 4

Amphidinols, which are polyketide metabolites chiefly comprising a long linear chain with polyhydroxyl groups and polyolefins, are produced by marine dinoflagellates Amphidinium carterae and A. klebsii. The acetate incorporation experiments of amphidinols 2, 3 and 4 revealed that they are built up with five regular C2-elongation sequences, which are separated by continuous acetate-methyl derived carbons. The findings support the C1-deletion mechanism from the regular sequence, which could be accounted for either by Favorski-type reaction or by Tiffeneau–Demjanov rearrengement.