s reticuline/coptis

S-Adenosyl-L-methionine:(R,S)-reticuline 7-O-methyltransferase converts reticuline to laudanine in tetrahydrobenzylisoquinoline biosynthesis in the opium poppy Papaver somniferum. This enzyme activity has not yet been detected in plants. A proteomic analysis of P. somniferum latex identified a gel

Cytochrome P450s (P450) play a key role in oxidative reactions in plant secondary metabolism. Some of them, which catalyze unique reactions other than the standard hydroxylation, increase the structural diversity of plant secondary metabolites. In isoquinoline alkaloid biosyntheses, several unique

In Coptis japonica cell cultures an alternative pathway has been discovered which leads from (S)-tetrahydrocolumbamine via (S)-canadine to berberine. The two enzymes involved have been partially purified. (S)-Tetrahydrocolumbamine is stereospecifically transformed into (S)-canadine under formation

Opium poppy (Papaver somniferum) produces a large number of benzylisoquinoline alkaloids, including morphine and sanguinarine, derived from tyrosine via the branch-point intermediate (S)-reticuline. Molecular clones for the three methlytransferases involved in (S)-reticuline biosynthesis,

Eschscholzia californica produces various types of isoquinoline alkaloids. The structural diversity of these chemicals is often due to cytochrome P450 (P450) activities. Members of the CYP719A subfamily, which are found only in isoquinoline alkaloid-producing plant species, catalyze methylenedioxy