TITLE:
GC/FT-IR Analysis of Novel 4,6,9-Triene and 2,4,6,9-Tetraene Occurring in a Female Pheromone Gland of Arctia plantaginis (Erebidae: Arctiinae)
AUTHORS:
Yuta Muraki, Rei Yamakawa, Masanobu Yamamoto, Hideshi Naka, Atsushi Honma, Johanna Mappes, Kaisa Suisto, Tetsu Ando
KEYWORDS:
Natural Products, Insect Sex Pheromone, GC/FT-IR, Wood Tiger Moth, (4E, 6Z, 9Z)-4, 6, 9-Henicosatriene, (2Z, 4E, 6Z, 9Z)-2, 4, 6, 9-Henicosatetraene
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.8 No.10,
October
26,
2017
ABSTRACT: Fifteen subspecies of the wood tiger moth, Arctia plantaginis (Lepidoptera: Erebidae: Arctiinae), have been
recorded in the Northern Hemisphere. An analysis of crude pheromone extracts by
GC equipped with an electroantennographic (EAG) detector showed four EAG-active
components (Comps. I–IV) that were commonly involved in the
pheromone glands of two subspecies inhabiting Japan and Finland. Comp. I is a major component (>75%) and the others are minor
components (3% - 15%). Their
mass spectra, measured by GC/MS,
revealed the chemical structures of C21 unsaturated hydrocarbons as
follows: 3,6,9-triene for Comp. I, 4,6,9-triene for Comp. II, 1,3,6,9-tetraene for Comp. III, and 2,4,6,9-tetraene for Comp. IV. Comps. I and III are known Type II
pheromone compounds, and their retention times coincide with those of the
authentic standards with all Z configurations. As a next step, the extract was analyzed by GC/FT-IR to
determine the configuration of Comps. II and IV. Their IR
spectra showed two characteristic C-H bending absorptions around 990 and 945 cm-1 due to the conjugated dienyl moieties; thus, Z and E configurations were assigned to
the double bonds at the 2- and 4-positions, respectively. Their Z double bonds
at the 6- and 9-positions are indicated by no absorptions around 970 cm-1, due
to the isolated double bonds with E configurations. Finally, the structures of Comps. II and IV were
confirmed by synthesis using a double Wittig
reaction. The synthetic (4E,6Z,9Z)-4,6,9-triene and (2Z,4E,6Z,9Z)-2,4,6,9-tetraene showed strong EAG
activity, and their chemical data coincided well with those of the natural
Comps. II and IV, indicating the correctness of the structure
determination by GC/FT-IR analysis and its usefulness for Type II pheromone
compounds.