Dual Engineering of Olivetolic Acid Cyclase and Tetraketide Synthase to Generate Longer Alkyl-Chain Olivetolic Acid Analogs

Engineering a promiscuous prenyltransferase for selective biosynthesis of an undescribed bioactive cannabinoid analog

Cannabinoids are unique meroterpenoids, with cannabigerolic acid (CBGA) serving as a dedicated precursor. This study introduces a fungal aromatic prenyltransferase AscC into the engineered Escherichia coli to catalyze the transfer of C5-C15 terpenoid linear precursors to olivetolic acid. Four CBGA derivatives (compounds 1-4) with diverse C5, C10, or C15 prenyl chains are isolated and identified, with compound 4 being an undescribed product featuring a C15 prenyl chain at the C-5 position. Compound 4 demonstrates the highest anti-neuroinflammatory and antibacterial activities, with IC50 values of 3.06 µM for TNF-α and 4.31 µM for IL-6, alongside EC50 values ranging from 0.87 to 3.16 µM against three Gram-positive bacteria. An efficient construct is established by incorporating an additional copy of AscC, resulting in a yield of 14.85 ± 0.91 mg/L of compound 4. Two mutants, L180Y and L180F, are engineered to selectively produce compound 4. These findings provide a foundation for enriching the chemical diversity of bioactive cannabinoid analogs with various prenyl moieties through combinatorial biosynthesis.

Improving CsOAC Activity in Saccharomyces cerevisiae for Directed Production of Olivetolic Acid through Rational Design

Olivetolic acid (OA) is an essential precursor in the cannabinoid biosynthesis. It is produced through a unique interaction between the two proteins, olivetol synthase (CsOLS) and olivetolic acid cyclase (CsOAC). When the OA biosynthesis is transferred to Saccharomyces cerevisiae, olivetol (OL) is produced as a side product, even with a high enhancement of copy number of CsOAC. In order to increase the OA titer while decreasing the OL titer in S. cerevisiae, rational design was applied to CsOAC using in silico approaches such as protein-ligand docking to find potential protein variants. In vivo screening and also testing different approaches for both proteins was applied to identify the best performing variants of CsOAC. Four variants were identified that gave the desired properties. The best CsOAC variant, G82 A/L92Y, resulted in a 1.7-fold increase in OA production and a shift in the ratio between the two products towards OA.

Identification and Optimization of more Efficient Olivetolic Acid Synthases

Introduction: Olivetolic acid (OLA) is a key intermediate in cannabidiol (CBD) synthesis, and cannabinoids are important neuroactive drugs. However, the catalytic activity of olivetolic acid synthase (OLS), the key enzyme involved in OLA biosynthesis, remains low and its catalytic mechanism is unclear. Materials and Methods: In this study, we conducted a scrupulous screening of the pivotal rate-limiting enzyme and analyzed its amino acid sites that are critical to enzyme activity as validated by experiments. Results: Through stringent enzyme screening, we pinpointed a highly active OLS sequence, OLS4. Then, we narrowed down three critical amino acid sites (I258, D198, E196) that significantly influence the OLS activity. Conclusions: Our findings laid the groundwork for the efficient biosynthesis of OLA, and thereby facilitate the biosynthesis of CBD.

Catalytic Potential of Cannabis Prenyltransferase to Expand Cannabinoid Scaffold Diversity

Biologically active cannabinoids are derived from cannabigerolic acid (CBGA), which is biosynthesized by aromatic prenyltransferase CsPT4. We exploit the catalytic versatility of CsPT4 to synthesize various CBGA analogues, including a geranylated bibenzyl acid, the precursor to bibenzyl cannabinoids of liverwort origin. The synthesized natural and new-to-nature cannabinoids exhibit potent cytotoxicity in human pancreatic cancer cells. CsPT4 can artificially extend the cannabinoid biosynthetic diversity with novel and improved biological activities.

Cannabis sativa: origin and history, glandular trichome development, and cannabinoid biosynthesis

Is Cannabis a boon or bane? Cannabis sativa has long been a versatile crop for fiber extraction (industrial hemp), traditional Chinese medicine (hemp seeds), and recreational drugs (marijuana). Cannabis faced global prohibition in the twentieth century because of the psychoactive properties of ∆9-tetrahydrocannabinol; however, recently, the perspective has changed with the recognition of additional therapeutic values, particularly the pharmacological potential of cannabidiol. A comprehensive understanding of the underlying mechanism of cannabinoid biosynthesis is necessary to cultivate and promote globally the medicinal application of Cannabis resources. Here, we comprehensively review the historical usage of Cannabis, biosynthesis of trichome-specific cannabinoids, regulatory network of trichome development, and synthetic biology of cannabinoids. This review provides valuable insights into the efficient biosynthesis and green production of cannabinoids, and the development and utilization of novel Cannabis varieties.

Novel insights into the antibacterial activities of cannabinoid biosynthetic intermediate, olivetolic acid, and its alkyl-chain derivatives

Investigations of antibacterial activities revealed that the incorporation of longer alkyl chains to the C-6 position in resorcylic acid conferred antibacterial properties against Staphylococcus aureus and Bacillus subtilis. The resultant olivetolic acid (OA) derivatives with n-undecyl and n-tridecyl side-chains, even those lacking the hydrophobic geranyl moiety from their C-3 positions, exhibited strong antibacterial activities against B. subtilis at a MIC value of 2.5 μM. Furthermore, the study demonstrated that the n-heptyl alkyl-chain modification at C-6 of cannabigerolic acid (CBGA) effectively enhanced the activity against B. subtilis, demonstrating the importance of the alkyl side-chain in modulating the bioactivity. Overall, the findings in this study provided insight into further evaluations of the antibacterial activities, as well as other various biological activities of OA and CBGA derivatives, especially with optimized hydrophobicities at both the alkyl and prenyl side-chain positions of the core skeleton for the discovery of novel drug seeds.