In vitro Applications of the Terpene Mini-Path 2.0.

In 2019 four groups reported independently the development of a simplified enzymatic access to the diphosphates (IPP and DMAPP) of isopentenol and dimethylallyl alcohol (IOH and DMAOH). The former are the two universal precursors of all terpenes. We report here on an improved version of what we call the terpene mini-path as well as its use in enzymatic cascades in combination with various transferases. The goal of this study is to demonstrate the in vitro utility of the TMP in, i) synthesizing various natural terpenes, ii) revealing the product selectivity of an unknown terpene synthase, or iii) generating unnatural cyclobutylated terpenes.

The Terpene Mini-Path, a New Promising Alternative for Terpenoids Bio-Production.

Terpenoids constitute the largest class of natural compounds and are extremely valuable from an economic point of view due to their extended physicochemical properties and biological activities. Due to recent environmental concerns, terpene extraction from natural sources is no longer considered as a viable option, and neither is the chemical synthesis to access such chemicals due to their sophisticated structural characteristics. An alternative to produce terpenoids is the use of biotechnological tools involving, for example, the construction of enzymatic cascades (cell-free synthesis) or a microbial bio-production thanks to metabolic engineering techniques. Despite outstanding successes, these approaches have been hampered by the length of the two natural biosynthetic routes (the mevalonate and the methyl erythritol phosphate pathways), leading to dimethylallyl diphosphate (DMAPP) and isopentenyl diphosphate (IPP), the two common universal precursors of all terpenoids. Recently, we, and others, developed what we called the terpene mini-path, a robust two enzyme access to DMAPP and IPP starting from their corresponding two alcohols, dimethylallyl alcohol and isopentenol. The aim here is to present the potential of this artificial bio-access to terpenoids, either in vitro or in vivo, through a review of the publications appearing since 2016 on this very new and fascinating field of investigation.