Expanding the Diversity of Plant Monoterpenoid Indole Alkaloids Employing Human Cytochrome P450 3A4

Abstract

Human drug‐metabolizing cytochrome P450 monooxygenases (CYPs) have enormous substrate promiscuity; this makes them promising tools for the expansion of natural product diversity. Here, we used CYP3A4 for the targeted diversification of a plant biosynthetic route leading to monoterpenoid indole alkaloids. In silico, in vitro and in planta studies proved that CYP3A4 was able to convert the indole alkaloid vinorine into vomilenine, the former being one of the central intermediates in the ajmaline pathway in the medicinal plant Rauvolfia serpentina (L.) Benth. ex Kurz. However, to a much larger extent, the investigated conversion yielded vinorine (19 R ,20R)‐epoxide, a new metabolite with an epoxide functional group that is rare for indole alkaloids. The described work represents a successful example of combinatorial biosynthesis towards an increase in biodiversity of natural metabolites. Moreover, characterisation of the products of the in vitro and in planta transformation of potential pharmaceuticals with human CYPs might be indicative of the route of their conversion in the human organism.

Engineering cellular metabolite transport for biosynthesis of computationally predicted tropane alkaloid derivatives in yeast

“…We detected TA N-oxygenation only by the PNO derived from the omniherbivorous Z. variegatus, consistent with its need to detoxify a broader range of dietary plant alkaloids relative to specialist herbivores (50,53). Our results contribute to a growing body of evidence that enzymes used for PNP detoxification can be co-opted to expand biosynthetic diversity in engineered hosts (61).…”

Total Synthesis of Vinorine

“…Corey–Kim oxidation of 29 followed by a bioinspired cyclization (Scheme ) furnished the total synthesis of vinorine ( 1 ). The NMR spectra of our synthetic sample agree well with the reported data …”

“…The NMR spectra of our synthetic sample agree well with the reported data. 22 Table 1. Optimization of the Proposed Cyclization a entry oxidants (equiv), additives (equiv), and oxidation times, then Lewis acids (equiv) yields Reactions were conducted with 0.2 mmol of 14 in solvents (5 mL) at 0 °C to rt.…”

“…The ajmaline type alkaloid vinorine (Figure A, 1 ), a flagship intermediate in the sarpagine/ajmaline biosynthetic pathway, , is a neuroprotective agent for treatment of sciatic nerve crush injury by regulation of nerve growth factor (NGF) and its downstream extracellular signal-regulated kinase (ERK) activity . Although vinorine is an important natural product in ajmaline type alkaloids, to our knowledge, vinorine and its related alkaloids (Figure A) are not yet completed by total synthesis.…”

Natural Product Diversification by One‐Step Biocatalysis using Human P450 3A4

“…Hence, there are few studies that consciously re-purpose human liver P450s as catalysts for the synthetic manipulation of natural products that are not necessarily of immediate pharmaceutical importance. Recently, Sheludko et al reported the successful diversification of an indole alkaloid intermediate in a plant natural product biosynthesis using P450 3A4 in vitro and in planta [37] and we obtained new insight into the degree of P450 3A4-catalysed diversification of the steroid testosterone during the preparative-scale synthesis of its metabolites using the monooxygenase in form of a whole-cell biocatalyst expressed in Pichia pastoris. [38] Encouraged by these studies, we hypothesised that this human P450 would not only accept, but also diversify a wide range of different natural products to a similar extent as the model substrate testosterone.…”