PYRROLIZIDINE ALKALOIDS FROM CRYPTANTHA SPECIES

In the first alkaloid investigation of the genus Cryptantha (Boraginac eae), pyrrolizidine alkaloids were identified from C. cana, C. clevela ndii, C. confertiflora, C. flava, C. fendleri, C. leiocarpa, C. thyrsi flora, C. virgata and C. virginensis. Six perennial species from secti on (or subgenus) Oreocarya were similar in their alkaloid content, whi ch was dominated by lycopsamine and intermedine and in some species wi th their acetyl derivatives. In two other species from this section, a mabiline and tessellatine (heliospathine) were also major components. In contrast, in three annual species from section (or subgenus) Krynit zkia, the major pyrrolizidine alkaloids were angelylretronecine and ec hiumine derivatives. New pyrrolizidine alkaloids found were threo-2'', 3''-dihydroxyechiumine, erythro-3''-chloro-2''-hydroxyechiumine and 2' ',3''-epoxyechiumine.