Evaluation of Biosynthetic Pathway and Engineered Biosynthesis of Alkaloids

Abstract

Abstract:Varieties of alkaloids are known to be produced by various organisms, including bacteria, fungi and plants, as secondary metabolites that exhibit useful bioactivities. However, understanding of how those metabolites are biosynthesized still remains limited, because most of these compounds are isolated from plants and at a trace level of production. In this review, we focus on recent efforts in identifying the genes responsible for the biosynthesis of those nitrogen-containing natural products and elucidating the mechanisms involved in the biosynthetic processes. The alkaloids discussed in this review are ditryptophenaline (dimeric diketopiperazine alkaloid), saframycin (tetrahydroisoquinoline alkaloid), strictosidine (monoterpene indole alkaloid), ergotamine (ergot alkaloid) and opiates (benzylisoquinoline and morphinan alkaloid). This review also discusses the engineered biosynthesis of these compounds, primarily through heterologous reconstitution of target biosynthetic pathways in suitable hosts, such as Escherichia coli, Saccharomyces cerevisiae and Aspergillus nidulans. Those heterologous biosynthetic systems can be used to confirm the functions of the isolated genes, economically scale up the production of the alkaloids for commercial distributions and engineer the biosynthetic pathways to produce valuable analogs of the alkaloids. In particular, extensive involvement of oxidation reactions catalyzed by oxidoreductases, such as cytochrome P450s, during the secondary metabolite biosynthesis is discussed in details.

Efficient biosynthesis of heterodimeric C3-aryl pyrroloindoline alkaloids

“…Instead of CDPS, A. flavus uses nonribosomal peptide synthase (NRPS) to synthesize the cyclodipeptide substrate and a P450 enzyme, DtpC, for catalyzing the dimerization. DtpC is proposed to initiate the reaction by abstracting a hydrogen from N 10 or N 1′ of the cW L -P L substrate to form N 10 • radical 13 or N 1 ′• radical 14 . N 10 -radical (N 10 •) undergoes intramolecular addition to C 2 to form the pyrroloindoline C 3 -radical.…”

Unraveling the metabolic response of Brassica oleracea exposed to Xanthomonas campestris pv. campestris

“…The definition of alkaloids has now been expanded to include all compounds that can produce pronounced physiological responses and exhibit basicity that is attributed to the presence of nitrogen . Belonging to this group, we identified an isoquinoline N ‐oxide, which showed a high induction peak during late response.…”

Whole-genome sequencing of Aspergillus tubingensis G131 and overview of its secondary metabolism potential

“…However, none of the two cytochromes P450 present in the SM cluster 46 shows homology with DptC. Indeed, asperazine dimerization is based on a C3-C7 linkage which is not observed in such compounds so far [50]. Kishimoto et al proposed that biosynthesis of dimeric diketopiperazines, such as asperazine, is catalyzed by P450 cytochromes with relaxed substrate specificity [50].…”

“…Indeed, asperazine dimerization is based on a C3-C7 linkage which is not observed in such compounds so far [50]. Kishimoto et al proposed that biosynthesis of dimeric diketopiperazines, such as asperazine, is catalyzed by P450 cytochromes with relaxed substrate specificity [50]. This suggest that cytochromes P450 putatively required for asperazine production could be different from the one of ditryptophenaline biosynthesis in A. flavus and that cluster 46 could be the SM cluster for asperazine biosynthesis in A. tubingensis G131.…”