Peltate Glandular Trichomes of <i>Colquhounia coccinea</i> var. <i>mollis</i> Harbor a New Class of Defensive Sesterterpenoids

Abstract

A new class of unique sesterterpenoids, colquhounoids A–C (<b>1</b>–<b>3</b>), were identified from the peltate glandular trichomes of <i>Colquhounia coccinea</i> var. <i>mollis</i> (Lamiaceae) through precise laser-microdissection coupled with UPLC/MS/MS and spectroscopic analyses and X-ray diffraction. Very interestingly, their structural features and defensive function are closely related to leucosceptroid-class sesterterpenoids harbored by the glandular trichomes of another Lamiaceae taxon, <i>Leucosceptrum canum</i>, even though this is morphologically distinct and taxonomically distant