GC-MS analysis of enzyme products from recombinant MrTPS1, MrTPS2, MrTPS3, MrTPS4, and MrTPS5. (A) Sesquiterpene products from MrTPS1, MrTPS2, MrTPS3 and MrTPS5. (B) Monoterpene products from MrTPS4. The enzymes were expressed in E. coli, extracted, partially purified, and incubated with the substrates FPP (A) and GPP (B). Products were collected with a solid-phase microextraction (SPME) fiber and analyzed by GC-MS. Analysis of MrTPS3 products was performed using a decreased GC injection temperature (150°C). 1, (E)-β-caryophyllene; 2, α-humulene; 3, silphinene; 4, modeph-2-ene; 5, α-isocomene; 6, β-isocomene; 7, β-elemene; 8, germacrene A; 9, germacrene D; 10, (Z)-β-ocimene; 11, (E)-β-ocimene. Structures of TPS products are presented in (C).