EXTERNAL FLAVONOIDS FROM HELIOTROPIUM MEGALANTHUM AND H. HUASCOENSE (BORAGINACEAE). CHEMOTAXONOMIC CONSIDERATIONS
Author
URZUA,ALEJANDRO
MODAK,BRENDA
VILLARROEL,LUIS
TORRES,RENE
ANDRADE,LUZ
MENDOZA,LEONORA
WILKENS,MARCELA
Abstract
From the CH2Cl2 washings of fresh Heliotropiumspp. (Cochranea section), flavonoids and aromatic geranyl derivativeshave been isolated. Among the flavonoids, flavanones and flavonols arethe most common compounds, and only few flavones have been reported. Inthis communication we report the isolation of several flavonoids from theexudates of H. megalanthum, and H. huascoense. Two of thecompounds isolated from H. huascoense are novel flavonoids, belongingto the uncommon groups of penta-O-substituted flavanones and hexa-O-substitutedflavonols. Our results show a different external flavonoid compositionof H. huascoense from the other Heliotropium spp. so farstudied. They are supported by morphological considerations, in special,the presence or absence of glandular trichomes in Heliotropium spp