Terpenoids are the largest group of plant specialized (secondary) metabolites. These naturally occurring chemical compounds are highly diverse in chemical structure. Although there have been many excellent studies of terpenoids, most have focused on compounds built solely of isoprene units. Plants, however, also contain many 'atypical' terpenoids, such as glycosylated volatile terpenes and composite-type terpenoids, the latter of which are synthesized by the coupling of isoprene units on aromatic compounds. This mini review describes these 'hidden' terpenoids, providing an overview of their biosynthesis, localization, and biological and ecological activities.
Keywords: Glycosylation; Mutualism; Prenylated coumarin; Prenylated flavonoid; Shikonin; Terpenoid.
© The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.