Methyl 11-Oxoundecanoate is an intermediate in the synthesis of (11E)?-11-?Hexadecenoic Acid Methyl Ester (H635240), a fatty acid methyl ester produced by green seaweeds and Trachyrhamphus serratus. (11E)?-11-?Hexadecenoic acid methyl ester extracted from displays Trachyrhamphus serratus antitumor activity.