Orphan flavonoids and dihydrochalcones from Primula exudates.

Two orphan flavonoids containing an oxepin structure in ring A and named as Primcortusin (1) and 3'-OH-Primcortusin (2) were isolated from leaf exudates of Primula cortusoides, while P. glutinosa exudates yielded two dihydrochalcone derivatives (3,4). These novel structures have not been detected in other species of Primula so far.

Flavonoids in selected Primula spp.: bridging micromorphology with chemodiversity.

A combined study was carried out on the micromorphology and chemistry of glandular trichomes with focus on Primula vialii and P. vulgaris, respectively. Epifluorescence microscopy was applied to study the auto-fluorescent properties of flavonoids and their localization in glandular trichomes.

Diversification of exudate flavonoid profiles in further Primula spp.

In continuation of previous work, exudate flavonoid profiles of 22 new accessions of the genus Primula L. aligned to different subgenera were studied for the first time. Profiling was done by comparative TLC and UV-HPLC against authentic marker compounds.

Unusual compounds from exudates of Dionysia diapensifolia and D. gaubae var. megalantha (Primulaceae).

Exudates of Dionysia diapensifolia yielded (R)-(+)-3-acetoxy-3-phenyl-propiophenone as a new natural product with a basic dihydrochalcone structure, which was elucidated unequivocally by mass spectrometry and NMR spectroscopy. The sesquiterpenoidcarissone was found as the major compound in the exudate of D. gaubae var.

Exudate flavonoids of Primula spp: structural and biogenetic chemodiversity.

Several new accessions of the genus Primula and of the closely related Cortusa matthioli have been studied for their exudate flavonoid profiles. Unsubstituted flavone, 5-hydroxy-, 2'-hydroxyflavone and 5,2'-dihydroxyflavone were found as main components. Several other rather unusual substitution patterns were also found.