Firefly Photuris

Methylisoquinolinium 2-carboxylate (230), originally prepared by Quast (70LA64), was recently identified as a defensive betaine from Photuris versicolor fireflies (99JNP378). It is a pseudo-cross-conjugated mesomeric betaine isoconjugate to the odd alternant hydrocarbon 2-isopropenyl-naphthalene anion which is an odd alternant hydrocarbon anion. This compound therefore is a member of class 13, which is very rare. The UV absorption maxima Imax (methanol) were found at 235 (4.35), 320 (shoulder, 3.97), and 326 (3.99) nm. This compound undergoes similar reactions as Homarine 19 (Scheme 75). The NMR data are presented in Table VIII. 

Ye, L., Buck, L. M., Schaeffer, H. J., and Leach, F. R. (1997). Cloning and sequencing of a cDNA for firefly luciferase from Photuris pennsylvanica. Biochim. Biophys. Acta 1339 39-52. 

Gonzalez A., Hare J. F. and Eisner T. (1999b) Chemical egg defense in Photuris firefly femmes fatales. Chemoecology 9, 177-185. 

Barber H S. North American fireflies of the genus Photuris. Smithsonian Muse Coll 1951 117 1-58. 

The pyrido[2,3-/ ]pyrazines, 185-187, have been identified in the defensive secretion of the giant springtail, Tetrodontophora hidanensisP The secretion appears to confuse and strongly disorient potential predators. An unusual quinoline-derived betaine (188) with defensive properties was recently identified from the blood of Photuris versicolor fireflies. In addition, these fireflies chemical defense relies on sequestered cardiotonic steroids, the lucibufagins (see Section 2.04.3.3) (Figure 44). ... 

Lloyd, J. E. (1975) Aggressive mimicry in Photuris fireflies Signal repertoires by femmes fatales. Science, 187, 452-3. 

Lloyd, J. E. (1980) Male Photuris fireflies mimic sexual signals of their females prey. Science, 210, 669-71. 

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