This review páper summarizes the current knowledge of enzymes participating in the production of benzylisoquinoline alkaloids. This group of alkaloids comprises, e.g., morphine, codeine, thebaine, and sanginarine, which háve an irreplaceable position in pharmaceutical practice. For the time being, chemists háve not mana-ged to prepare them synthetically with sufficient efficacy, and therefore the study of the enzymology of their for-mation remains a topical problém. The páper pays particular attention to the knowledge of indiviďual enzymes on the molecular, or gene level. This very knowledge is essential for possible introduction of molecular-genetic approaches to the cultivation of plants producing therapeutically interesting benzylisoquinoline alkaloids

        Key words: benzylisoquinoline alkaloids - morphinans - benzophenanetridines - Pupav ferum L. - Eschscholtzia californica Chám.