“Green odor” and pyrethrin
Green odor emitted by leaves is composed of six unsaturated C6 alcohols and aldehydes with a Z- or E-double bond, as well as two saturated compounds. In response to environmental stimuli, neutral fats, phospho- and galactolipids in chloroplasts are hydrolyzed by lipolytic acyl hydrolase to yield α-linolenic and linoleic acids. Then, after subsequent action of lipoxygenase and hydroperoxide lyase, these acids yield (Z)-3-hexenal and n-hexanal via unstable (S)-13-hydroperoxide intermediates. Finally, by the action of alcohol dehydrogenase, these aldehydes are reduced to their corresponding alcohols. On the other hand, pyrethrin activity is induced by an original blend of green odor and (E)-β-farnesene, and is finally formed by lipase/esterase from chrysanthemoyl CoA and pyrethrolone, respectively. Specifically, the pyrethrin-forming activities are precisely controlled by the ratio of green odor and terpene. This novel finding means that green odor is a very important messenger of plant origin.
Hatanaka, A. 2017. “Green odor” and pyrethrin. Acta Hort. (ISHS) 1169:7-12
green odor, leaf alcohol, leaf aldehyde, tea chloroplasts, α-linolenic acid, lipoxygenase, hydroperoxide lyase, alcohol dehydrogenase, pyrethrin, chrysanthemoyl CoA, pyrethrolone