Lipoxygenase-catalysed co-oxidation for sustained production of oxyfunctionalized terpenoids

Lipoxygenases (LOX) catalyse allylic oxidations and epoxidations of a co-substrate in the presence of an unsaturated fatty acid containing a 1,4-pentadiene moiety. One- and two-step enzyme assays were established to verify the role or involvement of LOX in such co-oxidations. It was shown that LOX is only involved in the formation of reactive hydroperoxides, but not in the oxidation of a co-substrate, assuming a mechanism involving free peroxy radicals for the latter. Ten mono- and sesquiterpenes were used as co-substrates and the resulting products were analysed by mass spectrometry. A semi-preparative approach was developed using (+)-valencene as an example, and the resulting products were isolated by preparative GC and their structures elucidated by NMR spectroscopy

Rational reprogramming of the sesquiterpene synthase BcBOT2 yields new terpenes with presilphiperfolane skeleton

Computer-aided rational design of the substrate binding pocket of sesquiterpene synthases BcBOT2 from Botrytis cinerea yielded FPP cyclization products with presilphiperfolane backbone other than the naturally formed sesquiterpene presilphiperfolan-8β-ol. Particularly, amino acids W118 and F138 were found to strongly control the stability and conformation of key cationic intermediates. The W118Q variant forms only presilphiperfolan-9β-ol, whereas the exchange of amino acids at position 138, such as F138V, has a fundamental effect on the course of the cationic cascade. Here, the 1,3-hydride shift en route to presilphiperfolan-8β-ol is suppressed and substituted by a so far unknown 1,2-hydride shift that leads to presilphiperfol-1-ene and presilphiperfolan-1α-ol along with β-caryophyllene and the so far unknown caryophyllene-8β-ol