Kunert, M; Rahfeld, P; Shaker, K H; Schneider, B; David, A; Dettner, K; Pasteels, J M; Boland, W: Beetles Do It Differently: Two Stereodivergent Cyclisation Modes in Iridoid-Producing Leaf-Beetle Larvae, ChemBioChem, 14(3), 353-360 (2013), doi:10.1002/cbic.201200689

Larvae of the Chrysomelina species Phaedon cochleariae, Hydrothassa marginella, Phratora vulgatissima, Gastrophysa viridula, Gastrophysa atrocyanea, Gastrophysa cyanea and Gastrophysa polygoni produce the iridoid chrysomelidial (1) to defend themselves against predators. Feeding experiments with a deuterated precursor ([(2) H(5) ]8-hydroxygeraniol 9) and in vitro isotope exchange experiments with defensive secretion in (2) H(2) O revealed differences in the cyclisation of the ultimate precursor 8-oxogeranial (8) to 1, between members of the genus Gastrophysa and all other species. In P. cochleariae, H. marginella and P. vulgatissima 1 is most likely produced by a Rauhut-Currier-type cyclisation via a "transoid dienamine", with loss of a single deuterium atom from C(4) of the precursor. In contrast, members of the genus Gastrophysa cyclise 8 via a "cisoid dienamine" intermediate, with exchange of all three deuterium atoms from the methyl group at C(3). To study whether the different cyclisation modes influence the stereochemistry of 1, the absolute configuration of 1 of the larvae was determined by GC-MS on a chiral column. In accordance with literature (J. Meinwald, T. H. Jones, J. Am. Chem. Soc. 1978, 100, 1883 and N. Shimizu, R. Yakumaru, T. Sakata, S. Shimano, Y. Kuwahara, J. Chem. Ecol. 2012, 38, 29), we found (5S,8S)-chrysomelidial (1) in H. marginella and P. vulgatissima, but P. cochleariae and all investigated members of the genus Gastrophysa synthesise (5R,8R)-chrysomelidial (1).

There are additional file downloads belonging to this publication

Upcoming ...

BayCEER Colloquium:
Th. 2017-10-26
Electrical imaging of subsurface nano- and micro-scale particle injections for in situ groundwater remediation
Ökologisch-Botanischer Garten:
Th. 2017-10-26
Blumen.Berge.Erlebtes: Finissage
Su. 2017-11-05
Eiserne Reserve: Pflanzen mit Wintersteher-Früchten
Su. 2017-11-05
Leibniz, die Welt und wir - Malerei, Lithografie, Installation
Su. 2017-11-12
Unwiderstehlich: BlütendüftVortrag: Wild- und Nutzpflanzen
Weather research site
Luftdruck (356m): 973.6 hPa
Lufttemperatur: 6.8 °C
Niederschlag: 0.0 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 17m): 3.7 km/h
Wind (Max.): 7.2 km/h
Windrichtung: SO

Globalstrahlung: 9 W/m²
Lufttemperatur: 6.9 °C
Niederschlag: 0.1 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 32m): 9.8 km/h
Wind (Max.): 20.4 km/h