RESUMO
Commercial preparations of the Mexican herbal drug known as "miracle tea" (Packera candidissima and P. bellidifolia) have been profiled qualitatively by HPLC and GC-MS. Eremophilanes (3-7) were the major components found in the hexane-soluble fraction, while pyrrolizidine alkaloids (PAs) were identified in the alkaloid extracts. The content of free PAs and their N-oxides was determined for a total of 22 samples, and the results showed that the amount of these hepatotoxic compounds (0.0005-0.94% free PAs; 0.0004-0.55% N-oxides), through the presence of retrorsine (1) and senesionine (2) as the main constituents, may reach toxic levels. Hexane-soluble extracts from commercial presentations (dried whole plants) of both species afforded neoadenostylone (3), 6-(2-methylbutanoyloxy)-9-oxo-1-(10)-furanoeremophilene (4), and epineoadenostylone (5), in addition to methyl-4-hydroxyphenylacetate (8) and methyl-2-(1-hydroxy-4-oxocyclohexyl)acetate (9). Also, epicacalone (6) and the new compound 2ß-hydroxyneoadenostylone (7) were isolated from P. bellidifolia.
