1Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, D-38106 Braunschweig, Germany.
2Département de biologie, Université Laval, Quebec, P. Q., G1K 7P4, Canada.
In more than 50 lepidopteran species 2,5-Dialkyltetrahydrofurans were identified as
components of the cuticular lipids. The chain length of these compounds varies between
C25 and C37 and both cis- and trans-isomers are present.
In addition 2-alkyl-5-(1-hydroxyalkyl)tetrahydrofurans were found in some species. There is
a difference in the presence of THFs in the cuticular lipids of those butterflies and moths
examined. Of the 60 species of butterflies investigated 87% had THFs whereas they were
only found in 17% (two) of the 12 moth species examined. While THFs are present in 3rd
instar larvae (2-eicosyl- 5-undecyltetrahydrofuran and 2-octadecyl- 5-tridecyltetrahydrofuran)
of Pseudaletia unipuncta they are absent in both 6th instar larvae and adult males.
To elucidate the biosynthesis of both compounds the larvae were fed with different compounds
which are proposed to be involved in the biosynthesis as metabolites. Those compounds
(sec. alcohols, ketones and hydrocarbons) were synthesised and chemically labelled with
deuterium. Extraction of the larvae and analysis of the extracts by GC-MS show the
metabolism of the labelled compounds.
S. Schulz, G. Beccaloni, R. Nishida, Y. Roisin, R. I. Vane-Wright, J. N. McNeil, Z.
Naturforsch. 53c, 107-116 (1998).