Germacranes and Elemanes

Periplanones A-D act, in contrast to long-range pheromones, as close proximity sex-excitants They arc found in the alimentary tract and excreta of the female American cockroach Periplaneta americana, and cause the males to run and to perform the courtship display. Periplanones A and B, occurring in a ratio of 10 1, arc 100 times more active than C and D. 

About 50 elemanes known to date comprise p-elemenone from the oil of myrrh, representing the Cope rearrangement product of germacrone, (-)-bicycloelemene from peppermint oils of various provenance (e.g. Mentha piperita or Mentha ar-vensis), and p-elemol which is not only a minor component of Javanese oil of citro-nella but is also found in the elemi oil with an odor like pepper and lemon, expressed from the Manila elemi resin of the tree Canarum luzonicum (Burseraceae). 

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