Requires Mn2+ or Zn2+. Mg2+ is less effective than either. 1,8-Cineole is the main product from the enzyme with just traces of other monoterpenoids. The oxygen atom is derived from water. The reaction proceeds via linalyl diphosphate and alpha-terpineol, the stereochemistry of both depends on the organism. However neither intermediate can substitute for geranyl diphosphate. The reaction in Salvia officinalis (sage) proceeds via (-)-(3R)-linalyl diphosphate [1-3] while that in Arabidopsis (rock cress) proceeds via (+)-(3S)-linalyl diphosphate .
Monoterpene synthases from common sage (Salvia officinalis). cDNA isolation, characterization, and functional expression of (+)-sabinene synthase, 1,8-cineole synthase, and (+)-bornyl diphosphate synthase.