4.2.3.108	geranyl diphosphate + H2O = 1,8-cineole + diphosphate	-	-	
4.2.3.108	geranyl diphosphate + H2O = 1,8-cineole + diphosphate	proposed mechanism for the formation of 1,8-cineole, the reaction can proceed via (R)-alpha-terpinyl cation and (R)-alpha-terpineol, as well as via (S)-alpha-terpinyl cation and (S)-alpha-terpineol, the catalytic dyad is formed by H502 and E249. Depending on the stereochemistry of the intermediate, the protonation of the double bond of the alpha-terpinyl cation is provided by a proton relay via the hydroxyl groups of either Tyr496 or Thr278. The substrate GPP is ionized by diphosphate elimination, resulting in the geranyl cation. Subsequently, this cation is converted into the linalyl cation and alpha-terpinyl cation. The intermediate alpha-terpinyl cation is the precursor for all cyclic monoterpenes. 1,8-Cineol is possibly directly formed from geranyl diphosphate, and a cyclization reaction resulting in 1,8-cineole uses alpha-terpineol as a precursor. alpha-Terpineol is formed after water capture of the alpha-terpinyl cation	748984	
4.2.3.108	geranyl diphosphate + H2O = 1,8-cineole + diphosphate	substrate in left-hynded screw-sense orientation isomerizes to (3R)-linalyl diphosphate which in anti,endo-conformation cyclizes to the (4R)-alpha-terpinyl intermediate and thence to cineole following the addition of water	717147	
4.2.3.108	geranyl diphosphate + H2O = 1,8-cineole + diphosphate	syn-stereochemistry for both C-O-bond-forming steps. Reaction starts with allylic rearrangement of geranyl diphosphate to (R)-linalyl diphosphate, followed by SN' cyclization to alpha-terpineol and proton-induced cyclization of the C=C-double bond and the tertiary hydroxyl groups	717701	
4.2.3.108	geranyl diphosphate + H2O = 1,8-cineole + diphosphate	the substrate GPP is ionized by diphosphate elimination, resulting in the geranyl cation. Subsequently, this cation is converted into the linalyl cation and alpha-terpinyl cation. The intermediate alpha-terpinyl cation is the precursor for all cyclic monoterpenes. 1,8-Cineol is possibly directly formed from geranyl diphosphate, and a cyclization reaction resulting in 1,8-cineole uses alpha-terpineol as a precursor. alpha-Terpineol is formed after water capture of the alpha-terpinyl cation. Proposed mechanism for the formation of 1,8-cineole	748984