A new class of unique sesterterpenoids, colquhounoids A-C (1-3), were identified from the peltate glandular trichomes of Colquhounia coccinea var. mollis (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, Leucosceptrum canum, even though this is morphologically distinct and taxonomically distant.

The investigation methods, chemistry, bioactivities, and biosynthesis of non-volatile natural products involving 489 compounds in plant glandular trichomes are reviewed.