Carpophilus freemani

Nardi J. B., Dowd P. F. and Bartelt R. J. (1996) Fine structure of cells specialized for secretion of aggregation pheromone in a nitidulid beetle Carpophilus freemani (Coleoptera Nitidulidae). Tissue Cell 28, 43-52. 

The assembly of the carbon skeletons of these unusual hydrocarbons was first studied in Carpophilus freemani Dobson, through careful GC-MS and Nuclear Magnetic Resonance (NMR) studies of the incorporation of 2H or 13C-labeled precursors (Petroski et al., 1994). Assembly of the carbon skeleton of the aggregation pheromone of C. freemani, (2 , 4 , 6ii)-5-ethyl-3-methyl-2,4,6-nonatriene, involves initiation with acetate elongation with first propionate (to provide the methyl branch), then butyrate (to provide the ethyl branch) and chain termination with a second butyrate (Figure 6.7). At some point, loss of C02 from one of the butyrate units occurs to yield the appropriate hydrocarbon, but Petroski et al. (1994) were unable to determine which of the butyrate units loses its carboxyl group. Bartelt and Weisleder (1996) studied the biosynthesis of 15 additional methyl- and/or ethyl-branched, tri- and tetraenes in the related... 

Petroski R. J., Bartelt R. J. and Weisleder D. (1994) Biosynthesis of (2 ,4 ,6 )-5-ethyl-3-methyl-2,4,6-nonatriene the aggregation pheromone of Carpophilus freemani (Coleoptera Nitidulidae). Insect Biochem. Molec. Biol. 24, 69-78. 

Bartelt, R. J Dowd, P.F., Shorey, H.H. and Weisleder, D. (1990b). Aggregation pheromone of Carpophilus freemani (Coleoptera Nitidulidae) a blend of conjugated triene and tetraene hydrocarbons. Chemoecology, 1,105-113. 

Dowd, P.F. and Bartelt, R. J. (1993). Aggregation pheromone glands of Carpophilus freemani (Coleoptera Nitidulidae) and gland distribution among other sap beetles. Ann. Entomol. Soc. Am., 86, 464-469. 

Petroski, R. J. (1997). Improved preparation of Carpophilus freemani aggregation pheromone. Synthetic Commun., 27, 3279-3289. 

The biosynthesis of the major component of the male-produced aggregation pheromone of Carpophilus freemani beetles has been studied in detail by deuterium labelling. It was clear that the molecule was made up of one acetate unit, one propionate and two butyrates. The labelUng pattern indicated that decarboxylation was not the final step as would be expected, which left two possibilities, shown in Figure 4.11. 

Attractive Compounds. The male-produced pheromones of sap beetles, known so far, show the rather stereotypic structures 125-147 (Scheme 15) methyl- and ethyl-branched hydrocarbons with three or four (T)-configured conjugated double bonds [4]. Up to now, 23 compounds could be identified, forming species specific mixtures. Major components in the bouquets are (2E,4E,6E)-5-ethyl-3-methyl-2,4,6-nonatriene, 128, in Carpophilus davidsoni [268] as well as in C.freemani [269], (2 ,4 ,6 )-4,6-dimethyl-2,4,6-nonatriene, 129,in C. truncatus [270], (3 ,5 ,7 )-5-ethyl-methyl-3,5,7-undecatetraene, 132, in C. mutillatus [271],(2 ,4 ,6 ,8 )-3,5,7-trimethyl-2,4,6,8-decatetraene, 134,in C. hemipterus [272] as well as C. brachypterus [273], (2 ,4 ,6 ,8 )-3,5,7-tri-... 

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