Biosynthesis of Nature-Inspired Unnatural Cannabinoids

Abstract

Natural products make up a large proportion of medicine available today. Cannabinoids from the plant Cannabis sativa is one unique class of meroterpenoids that have shown a wide range of bioactivities and recently seen significant developments in their status as therapeutic agents for various indications. Their complex chemical structures make it difficult to chemically synthesize them in efficient yields. Synthetic biology has presented a solution to this through metabolic engineering in heterologous hosts. Through genetic manipulation, rare phytocannabinoids that are produced in low yields in the plant can now be synthesized in larger quantities for therapeutic and commercial use. Additionally, an exciting avenue of exploring new chemical spaces is made available as novel derivatized compounds can be produced and investigated for their bioactivities. In this review, we summarized the biosynthetic pathways of phytocannabinoids and synthetic biology efforts in producing them in heterologous hosts. Detailed mechanistic insights are discussed in each part of the pathway in order to explore strategies for creating novel cannabinoids. Lastly, we discussed studies conducted on biological targets such as CB1, CB2 and orphan receptors along with their affinities to these cannabinoid ligands with a view to inform upstream diversification efforts.

Structure-Guided Engineering of Prenyltransferase NphB for High-Yield and Regioselective Cannabinoid Production

“…first characterized by Kuzuyama et al and has been shown to be able to prenylate a variety of aromatic substrates including olivetolic acid (OA) to form CBGA . It serves as a suitable replacement to the CBGA synthase enzyme GOT in the synthetic pathway due to its highly soluble, well-characterized, and promiscuous nature . However, previous studies have shown that it produces a side product, 2- O -geranyl-olivetolic acid (2-O-GOA), by prenylating OA with geranyl pyrophosphate (GPP) on a different site as shown in Figure . , This diverts flux away from the cannabinoid producing pathway through CBGA and hence reduces the yield of cannabinoids obtainable.…”

Interaction of PKR with STCS1: an indispensable step in the biosynthesis of lunularic acid in Marchantia polymorpha

“…1), is posited to serve as the key intermediate in the pathway responsible for (bis)bibenzyl biosynthesis (Friederich et al ., 1999). Pre‐lunularic acid, the LA precursor, is most likely formed by a type III PKS enzyme, called STCS, that uses dihydro‐ p ‐coumaroyl‐CoA as the starter molecule to catalyze C2→C7 aldol condensation with retention of the carboxylate functional group (Austin & Noel, 2003; Lim et al ., 2021). A specific NADPH‐dependent PKR enzyme can reduce a particular keto group to a hydroxyl group within the polyketide molecules, followed by subsequent dehydration and aromatization (Bomati et al ., 2005).…”

Biosynthesis of Phytocannabinoids and Structural Insights: A Review

“…The main psychoactive constituent in cannabis is THC, and the main non-psychoactive compound is CBD, which accumulates in glandular trichomes and is obtained from plant tissue, flowers, and a high density of plant constituents [ 38 ]. The cannabinoid pathways involve the hexanoyl-CoA produced by an acyl-activating enzyme ( Cs AAE1) derived from hexanoic acid through the fatty acid biosynthesis pathway [ 39 ]. Hereafter, type III polyketide synthase olivetol synthase elongates toward hexanoyl-CoA using three units of malonyl-CoA and has characteristics of another type III polyketide synthase (PKSs) in flowering plants; this method of production requires significant resources and is an unsustainable avenue for harvesting cannabinoids, given its recent rapid expansion in demand worldwide [ 40 ].…”