ACYLPHLOROGLUCINOLS AND FLAVONOID AGLYCONES PRODUCED BY EXTERNAL GLANDS ON THE LEAVES OF 2 DRYOPTERIS FERNS AND CURRANIA-ROBERTIANA

The sparse resinous leaf exudates of Dryopteris villarii and D. arguta contain acylphloroglucinols that have previously only been found in t he rhizomes of Dryopteris species. The phloroglucinol derivatives were characterized as representatives of the para-aspidin, desaspidin and albaspidin series by 2-D NMR spectroscopy and atmospheric pressure che mical ionization mass spectrometry (APCI-MS-MS). Mass fragmentation pr oved to be of diagnostic value to identify the acyl side chains and al so allowed distinction between desaspidins and isomeric albaspidin ana logues. The frond exudate of Currania robertiana was devoid of acylphl oroglucinols, but was found to contain flavonoid aglycones. The acylph loroglucinols and flavonoid aglycones are presumably produced by exter nal glands on the leaves, the presence and ultrastructure of which was examined by scanning electron microscopy. (C) 1998 Elsevier Science L td. All rights reserved.