Metallophyte wastes and polymetallic catalysis: a promising combination in green chemistry. The illustrative synthesis of 5′-capped RNA

Abstract

The compatibility of metallic catalysts derived from plants was studied for the chemical solid-phase synthesis of a high added-value biomolecule: 5′-capped RNA (GpppRNA or ^7mGpppRNA) involved in many essential biological processes. These molecules are of great interest for biologists for structural and mechanistic studies of their complexes with RNA capping enzymes. Several polymetallic catalysts were prepared from various metallophytes species growing in mine sites in a context of phytoremediation programs. Their catalytic efficacy was evaluated for the coupling reaction of guanosine diphosphate (GDP) with a preactivated 5′-monophosphate hexathymidylate (pT₆) or a pRNA to form 5′-GpppT₆ or 5′-GpppRNA respectively. The direct coupling of ^7mGDP with pRNA was also investigated. With Zn-enriched catalysts obtained from Zn metallophytes, the capping yields were better than those obtained with conventional catalyst ZnCl₂. Interestingly with Ni-enriched plant extracts the yield was higher than with NiCl₂, a polymetallic catalysis was certainly involved. With this plant-inspired catalysis, metallophytes wastes become efficient and greener polymetallic catalysts. Finally, environmental benefits and effectiveness can be combined.