AUTHOR=Kilgore Matthew B. , Augustin Megan M. , May Gregory D. , Crow John A. , Kutchan Toni M. 

TITLE=CYP96T1 of Narcissus sp. aff. pseudonarcissus Catalyzes Formation of the Para-Para' C-C Phenol Couple in the Amaryllidaceae Alkaloids

JOURNAL=Frontiers in Plant Science

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.00225

DOI=10.3389/fpls.2016.00225

ISSN=1664-462X

ABSTRACT=<p>The Amaryllidaceae alkaloids are a family of amino acid derived alkaloids with many biological activities; examples include haemanthamine, haemanthidine, galanthamine, lycorine, and maritidine. Central to the biosynthesis of the majority of these alkaloids is a <italic>C-C</italic> phenol-coupling reaction that can have <italic>para-para', para-ortho'</italic>, or <italic>ortho-para'</italic> regiospecificity. Through comparative transcriptomics of <italic>Narcissus</italic> sp. <italic>aff. pseudonarcissus, Galanthus</italic> sp., and <italic>Galanthus elwesii</italic> we have identified a <italic>para-para' C-C</italic> phenol coupling cytochrome P450, CYP96T1, capable of forming the products (10b<italic>R</italic>,4a<italic>S</italic>)-noroxomaritidine and (10b<italic>S</italic>,4a<italic>R</italic>)-noroxomaritidine from 4′-<italic>O</italic>-methylnorbelladine. CYP96T1 was also shown to catalyzed formation of the <italic>para-ortho'</italic> phenol coupled product, <italic>N</italic>-demethylnarwedine, as less than 1% of the total product. <italic>CYP96T1</italic> co-expresses with the previously characterized norbelladine 4′-<italic>O</italic>-methyltransferase. The discovery of CYP96T1 is of special interest because it catalyzes the first major branch in Amaryllidaceae alkaloid biosynthesis. CYP96T1 is also the first phenol-coupling enzyme characterized from a monocot.</p>