The juvenile hormone (JH) is one of the key insect hormones. Here we describe the novel structure of the heteropteran JH, named JHSB_3. We hypothesized four candidate structures 1-4 as a result of the following experimental results: 1) The in vitro product of the corpus allatum (CA) of a stink bug, Plautia crossota stali, analyzed by gas chromatography/chemical ionization-mass spectrometry (GC/MS) showed a molecular mass ion peak at m/z 300 [M+NH_4]^+, 2) The high resolution fast atom bombardment mass spectrometry of the same sample gave the exact mass ion peak [M+H]^+ of 283.1885 suggesting a molecular formula, C_<16>H_<27>O_4, identical to that of JHB_3, 3) Enhanced JH production by CA in vitro by the addition of excess E, E-farnesol to the medium, indicated an E,E-farnesol skeleton for the heteropteran JH. The four candidates were stereoselectively synthesized in an enantiomeric pure form via Katsuki-Sharpless epoxidation and Sharpless dihydroxylation reactions. The juvenilizing effect of the bisepoxides 1-4 on metamorphosis of the bug showed that 1 and 2 were more potent than 3 and 4. When the CA product was subjected to a chiral GC/MS, the CA product and 2 had the same retention time. Thus, the structure of the native JH in P.c. stali was determined as 2.
