the majority ( 85 % ) of 394 monarch butterflies sampled from overwintering sites in mexico contain the same epoxy cardenolide glycosides , including most conspicuously a novel polar glycoside with a single genin-sugar bridge ( aspecioside ) , as occur in the milkweedsasclepias speciosa anda . syriaca .
C0017977
glycosides
C0007004
sugar