Accumulation of furanic labdane diterpenes has been investigated in different parts
of field-grown plants of Marrubium vulgare (Lamiaceae) and Leonurus cardiaca (Lamiaceae). Furanic labdane diterpenes were produced and accumulated only in the
aerial parts. Greatest amounts were measured in leaves and flowers. Up to 4 mg furanic
labdane diterpenes per g fresh weight were found. Accumulation of furanic labdane
diterpenes in plantlets seemingly depends on a developmental programme. No furanic
labdane diterpenes were detected in plantlets during the first four to five weeks
following germination. At this time the leaves became more differentiated and the
number of trichomes on leaves was obviously increasing. Young leaves and buds contained
most furanic labdane diterpenes. It was proven that at least a part of the non-volatile
furanic labdane diterpenes is stored in peltate glandular trichomes. NMR signals of
marrubiin were investigated with correlated spectra. Some 1H- and 13C-NMR assignments reported in literature were revised.
Lamiaceae -
Marrubium vulgare
-
Leonurus cardiaca
- diterpenes - labdane - glandular trichomes
