Highly efficient synthesis of the natural product β-himachalene in yeast and its potential as a novel anti-HSV-1 therapeutic agent

Terpenoids, a high-value natural product family in nature, have garnered significant attention due to their diverse pharmaceutical activities. However, the current supply of most structurally complex terpenoids relies predominantly on plant extraction, and supply insufficiency has become a critical challenge. In this study, targeting the sesquiterpene synthase PoTPS01 from Platycladus orientalisi, we screened efficient expression cassettes through promoter engineering and achieved, for the first time, the biosynthesis of β-himachalene in Saccharomyces cerevisiae, with an initial titer of 1.11 mg/L. To further enhance production, we employed strategies including utilizing a fusion protein expression approach and optimizing fermentation conditions, ultimately increasing the β-himachalene titer to 2.12 g/L. Furthermore, we conducted an in-depth investigation into the bioactivity of β-himachalene and discovered its significant antiviral activity against Herpes Simplex Virus type 1 (HSV-1). β-himachalene effectively inhibited the viral titer of both wild-type and acyclovir-resistant HSV-1 strains, exerting its inhibitory effect during the early stages of viral replication. This research not only provides a novel strategy for the biosynthesis of other high-value plant natural products but also paves new avenues for the development of novel drugs based on sesquiterpenoids.