Chemical composition of the defensive secretion of the longhorned beetle, Chloridolum loochooanum.
Adults of the longhorned beetle, Chloridolum loochooanum Gressitt (Coleoptera: Cerambycidae) emit a white frothy secretion from their metasternal glands. This defensive substance contains cyclopentanoid monoterpenoids (iridodials), whose structures were elucidated by gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) analyses that compared the naturally occurring structures with synthesized versions. Optically active citronellals, [(S)-, (R)-, and (S)/(R)- mixture], were used as starting materials for synthesizing the corresponding iridodials for the determination of the absolute configuration of the natural product. The retention time of (2S)-iridodial, derived from (S)-citronellal, corresponded to that of C. loochooanum iridodial by enantioselective GC analysis. Thus, we suggest that the absolute configuration of C. loochooanum iridodial is (1R,2S,5S)-iridodial.
Ohmura
Wakako
W
Forestry and Forest Products Research Institute, Tsukuba, Japan. murasan@ffpri.affrc.go.jp
Hishiyama
Shojiro
S
Nakashima
Tadakazu
T
Kato
Atsushi
A
Makihara
Hiroshi
H
Ohira
Tatsuro
T
Irei
Hideki
H
D000818:Animals; D001517:Coleoptera / Q000737:chemistry*; D005088:Exocrine Glands / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D039823:Iridoids / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013237:Stereoisomerism
D039823:Iridoids; C527058:iridodial