The Chemistry of Some Dalodesmidean Millipedes from Tasmania (Diplopoda, Polydesmida)

Abstract

Millipedes (Diplopoda) are well known for their toxic or repellent defensive secretions. As part of a larger investigation, we describe the chemical constituents of 14 species of Tasmanian millipedes in seven genera. Six species in the genus Gasterogramma were found to produce acyclic ketones, including the pungent unsaturated ketones 1, 2, and 6, and the novel (rel-3R,5S,7S)-3,5,7-trimethyl-2,8-decanedione (7b), for which the stereoconfiguration was established by stereoselective syntheses of pairs of isomers. These compounds have not been detected before in millipede defensive secretions. This report is the first on species of the suborder Dalodesmidea (Polydesmida), a dominant component of the soil and litter fauna of the temperate regions of the Southern Hemisphere.

Millipedes vs. pathogens: Defensive secretions of some julids (Diplopoda: Julida) as potential antimicrobial agents

“…This is the first report of the presence of ketones in julid defensive systems. Previously, aromatic (Makarov et al., ), acyclic (Jones et al., ) and unsaturated (Jones et al., ) ketones were reported as compounds of polydesmidan defensive systems. The presence of ketones in defensive gland secretions can be explained by the fact that alkyl‐ p ‐benzoquinones and ketones can share similar precursors during biosynthesis (Blum, ; Meinwald, Koch, Rogers, & Eisner, ).…”

“…This is the first report of the presence of ketones in julid defensive systems. Previously, aromatic (Makarov et al, 2010), acyclic (Jones et al, 2018) and unsaturated (Jones et al, 2018) Rogers, & Eisner, 1966). In millipedes, the pathways of biosynthesis of p-benzoquinones were traced in Narceus gordanus (Chamberlin, 1943), N. annularis (Rafinesque, 1820), Cambala annulata (Say, 1821) and Rhinocricus holomelanus Pocock, 1894 (Blum, 1987;Weatherston & Percy, 1970).…”

Deoxybuzonamine Isomers from the Millipede Brachycybe lecontii (Platydesmida: Andrognathidae)

“…3 The chemical defenses present in millipedes were the subject of a recent review, and research describing the diversity of chemicals in this group of animals continues to receive important attention. 1,4,5 The novel alkaloids buzonamine and nitropolyzonamine were found in the secretions of Buzonium crassipes and Petaserpes cryptocephalus (=Polyzonium rosalbum), respectively. 6−8 Recently, we described a 7-substituted indolizidine, gosodesmine, from the platydesmidan millipede Gosodesmus claremontus.…”

Gosodesmine, a 7-Substituted Hexahydroindolizine from the Millipede Gosodesmus claremontus

“…2,3 The chemical defenses present in millipedes were the subject of a recent review, and research describing the diversity of chemicals in this group of animals continues to receive important attention. 1,4,5 Here we describe gosodesmine (1), a novel alkaloid with some terpene character found in the chemical defense secretions of the millipede Gosodesmus claremontus Chamberlin (Colobognatha, Platydesmida, Andrognathidae).…”

“…When used in defense against predation, these defensive secretions can ooze out in droplets, flow passively across the cuticle, or be ejected as a stream or spray . The toxicity of these chemicals in some species can blind chickens and kill lizards. , The chemical defenses present in millipedes were the subject of a recent review, and research describing the diversity of chemicals in this group of animals continues to receive important attention. ,, Here we describe gosodesmine ( 1 ), a novel alkaloid with some terpene character found in the chemical defense secretions of the millipede Gosodesmus claremontus Chamberlin (Colobognatha, Platydesmida, Andrognathidae).…”