Final steps in Ips bark beetle pheromone production

Our understanding of ipsdienol production has evolved from where is was thought that host tree derived myrcene was hydroxylated to ipsdienol to our current recognition that ipsdienol is made de novo. The cytochrome P450 hydroxylation steps do not confer the final stereochemistry required by Ips spp. for ipsdienol, but rather an oxidoreductase oxidizes ipsdienol to ipsenone which the same oxidoreductase can then reduce to the stereo-specific (+)/(-)blend of ipsdienol. This oxidoreductase has been isolated from I. pini, expressed, and a kinetic analysis of substrate/product specificity strongly suggests that this enzyme controls the final stereochemistry of ipsdienol.