New Frond Exudate Flavonoids From Cheilanthoid Ferns

Abstract

A series of new flavonoid aglycones have been identified in the frond exudates of the fern Cheilanthes argentea, in five species of Notholaena, in Pityrogramma triangularis, and in Platyzoma microphylla. These aglycones comprise several rare flavonoids and five novel natural products: 5,7,8-trihydroxy-3-methoxy-6-methyl flavone, 3,5,2′-trihydroxy-7,8,4′-trimethoxy flavone, 5,2′-dihydroxy-3,7,8-trimethoxy flavone, 5,7,4′-trihydroxy-2′-methoxy flavanone, and 3,5,4′-trihydroxy-6,7,8-trimethoxy flavone. The novel flavonoids were characterized by their N M R spectral data