Benzophenanthridines belong to the benzylisoquinolic alkaloids, representing one of the main groups of this class. These alkaloids include over 120 different compounds, mostly in plants from the Fumariaceae, Papaveraceae, and Rutaceae families, which confer chemical protection against pathogens and herbivores. Industrial uses of BZD include the production of environmentally friendly agrochemicals and livestock food supplements. However, although mainly considered toxic compounds, plants bearing them have been used in traditional medicine and their medical applications as antimicrobials, antiprotozoals, and cytotoxic agents have been envisioned. The biosynthetic pathways for some BZD have been established in different species, allowing for the isolation of the genes and enzymes involved. This knowledge has resulted in a better understanding of the process controlling their synthesis and an opening of the gates towards their exploitation by applying modern biotechnological approaches, such as synthetic biology. This review presents the new advances on BDZ biosynthesis and physiological roles. Industrial applications, mainly with pharmacological approaches, are also revised.

Abstract. Seeds of Argemone mexicana L. accumulate significative amounts of sanguinarine. The analysis of the distribution of this alkaloid through the tissues of mature seeds revealed that up to 60 % of its contents was found tightly fixed to the different components of the seed external covers where it persisted during seedling germination. Contrastingly, sanguinarine contents in cotyledon accounted for the remaining 40 % and it could have been, at least partially, mobilized to the newly formed hypocotyls during emergence from seeds. Berberine was only detected in immature seeds and in seedlings once cotyledons were totally displayed. These results are discussed as a possible sanguinarine role in the chemical protection during seedlings germination.   Resumen. Semillas de Argemone mexicana L. acumulan cantidades elevadas de sanguinarina. Un análisis de la distribución de alcaloides en los diferentes tejidos que componen la semilla reveló que hasta un 60 % del contenido se encontraba fuertemente unido en las capas que forman la cubierta exterior, donde se retuvieron durante la emergencia del hipocótilo. En contraste, los cotiledones presentaron el 40 % restante y parte de ello pudo haber sido movilizado al hipocótilo al emerger. Berberina sólo se observó en semillas inmaduras y en plántulas en desarrollo con los cotiledones desplegados. Estos resultados se discuten en función del posible papel defensivo de la sanguinarina durante la germinación.

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A transcriptomic approach was employed to describe a set of putatively protein-coding sequences involved in biosynthesis of berberine and sanguinarine; the two major benzylisoquinoline alkaloids (BIA) from Argemone mexicana (L.; Papaveraceae). A robust de novo assembled transcriptome was obtained from developing seedlings. Initial screening identified 514 unigenes, from eight different Pfam domains, such as Cyt-P450 dependent proteins, which are recurrently involved in BIA biosynthesis. Additional annotation by KEGG Orthology and Gene Ontology supported putative participation of the selected proteins in alkaloid biosynthesis. Moreover, in silico structure prediction of sanguinarine reductase (SanR), dihydrobenzophenantridine oxidase (DHBO) and tetrahydroprotoberberine oxidase (STOX), involved in the last reactions of sanguinarine and berberine biosynthesis, fitted with that of previously characterized proteins from related species further supporting proper annotation. Hence, the pipeline analysis presented could provide a comprehensive description of the biosynthetic potential of this plant through the functionality associated with its transcripts.