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

Abstract

Millipedes (Diplopoda) are well known for their toxic or repellent defensive secretions. Here we describe gosodesmine (1), 7-(4-methylpent-3-en-1-yl)-1,2,3,5,8,8a-hexahydroindolizine, a unique alkaloid with some terpene character found in the chemical defense secretions of the millipede Gosodesmus claremontus Chamberlin (Colobognatha, Platydesmida, Andrognathidae). The structure of 1 was suggested by its mass spectra and GC-FTIR spectra and established from its 1H, 13C, and 2D NMR spectra and 1D NOE studies. The 7-substituted indolizidine carbon skeleton of 1 was confirmed by unambiguous synthesis. This is the first report of an alkaloid from a platydesmid millipede and the first report of a 7-substituted indolizidine from an arthropod.

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

“…While other alkaloids with terpene character, such as polyzonimine, nitropolyzonamine, and buzonamine, have been described from millipedes in the order Polyzoniida, − the presence of gosodesmine and deoxybuzonamine in millipedes in the order Platydesmida may suggest a common evolutionary origin of alkaloids in an ancestor of these evolutionary sisters. , Non-alkaloid terpenes such as pinenes in the order Siphonophorida, the close evolutionary sister of these orders, and others in Polyzoniida raise interesting questions about the evolution of these chemical defenses in millipedes.…”

“…6−8 Recently, we described a 7-substituted indolizidine, gosodesmine, from the platydesmidan millipede Gosodesmus claremontus. 9 Here we describe (6aR,10aS,10bR)-8,8-dimethyldodecahydropyrrolo[2,1-a]isoquinoline [trans-anti-trans-deoxybuzonamine (1a)] and (rel-6aR,10aR,10bR)-8,8-dimethyldodecahydropyrrolo[2,1-a]isoquinoline [trans-syn-cis-deoxybuzonamine (1b)], two diastereomers of buzonamine without the epoxide function, detected in the chemical defense secretions of the millipede Brachycybe lecontii Wood (Colobognatha, Platydesmida, Andrognathidae). 10,11 B. lecontii, a species endemic to the southeastern and central U.S. is a small-bodied (4−5 cm long) pink millipede that assembles into social aggregations called pinwheels in which the males exclusively care for the eggs.…”

“…When used in defense against predation, these secretions can ooze out in droplets, flow passively across the cuticle, or be ejected as a stream or spray . 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. ,, The novel alkaloids buzonamine and nitropolyzonamine were found in the secretions of Buzonium crassipes and Petaserpes cryptocephalus (= Polyzonium rosalbum ), respectively. − Recently, we described a 7-substituted indolizidine, gosodesmine, from the platydesmidan millipede Gosodesmus claremontus …”

Terpene synthases and pathways in animals: enzymology and structural evolution in the biosynthesis of volatile infochemicals

“…29–31 More recently, another alkaloid named gosodesmine ( 13 ), a 7-substituted hexahydroindolizine carrying an isoprenyl moiety, was detected in the millipede Gosodesmus claremontus of the related order Platydesmida . 32 Shear also found volatile monoterpenes such as limonene ( 14 ) in polyzoniidan and siphonophoridan millipedes. 29 How or whether any of these compounds are derived from millipede-specific biosynthetic pathways or dietary sources is currently unclear.…”

The Chemistry of the Defensive Secretions of three species of millipedes in the genus Brachycybe

“…(1), polyzonimines (2), and gosodesmine (3)] (Smolanoff et al 1975;Shear 2015;Hassler et al 2020;Jones et al 2022).…”