10-Hydroxy-delta 2-decenoic acid, an antibiotic found in royal jelly.

10-Hydroxy-Delta(2)-decenoic acid, the major component of the lipide fraction of royal jelly, exhibits antibiotic activity against many bacteria and fungi. This fatty acid is less than one-fourth as active as penicillin against Micrococcus pyogenes and less than one-fifth as active as chlortetracycline against Escherichia coli. It also slows the growth rate of Neurospora sitophila and some unidentified molds. The salt of this compound is considerably less active than the free acid.