Natural product synthesis
Enzyme Catalysis for Bio-Synthesis of Terpenes
Terpenes as Biofuels: Sustainable and biologically feasible fuels
The Terpene Systems:
Terpenes represent the largest class of natural products currently known. These natural compounds are derived from a few linear precursors, such as geranyl diphosphate (GPP, C10), farnesyl diphosphate (FPP, C15) and geranylgeranyl diphosphate (GGPP, C20). Terpenoids, which make up 60% of all natural products, have diverse biological functions that are widespread across all three domains of life. Terpenes are commonly used to provide fragrance and flavor, and are also used as drugs. Terpene synthases (TPSs) naturally catalyze the synthesis of terpenes via cationic mechanisms, which include numerous highly reactive intermediates. A common feature in all TPSs is highly evolved active sites that can seclude and protect highly reactive carbocation intermediates.
We have studied several TPSs using simulation tools. For instance, we are studying bornyl diphosphate synthase, trichodiene synthase, taxadiene synthase, and selinadiene synthase.
Interestingly, these natural products are also packed with energy, and therefore are potential candidates as advanced biofuel precursors. As an example, the fully reduced form of the linear terpene farnesene is currently being used as an alternative biosynthetic diesel. Even though plants are the main natural source of various classes of terpenes, engineered microbial platforms may be suitable and cost-effective approaches for the production of terpene-based advanced biofuels in industrial scale.
We study the structure, stability and thermochemistry of large classes of terpenes to find the most convenient candidates as biofuels. We have built a statistical model that allows scanning of various classes of terpene molecules as a potential petroleum fuel substitute, according to their calculated heat of combustion, heat of vaporization and heat of formation.