(-)-Camphene is the major product in Abies grandis (grand fir) with traces of other monoterpenoids . In Pseudotsuga menziesii (Douglas-fir) there are about equal parts of (-)-camphene and (-)-alpha-pinene with traces of four other monoterpenoids [2,3]. In Solanum lycopersicum (tomato) tricyclene, beta-myrcene, limonene, and traces of several other monoterpenoids are also formed . See also EC 126.96.36.199 myrcene synthase, EC 188.8.131.52 (4S)-limonene synthase, EC 184.108.40.206 (-)-alpha-pinene synthase and EC 220.127.116.11 tricyclene synthase.
product distribution varies with deuterium substitution at C4 and C10 of substrate. Kinetic isotope effects strongly indicate multiple bicyclic olefin production through the partitioning of common carbocation intermediates
replacement of selected amino acid residues in (-)-pinene synthase with the corresponding residues from (-)-camphene synthase in an effort to identify the amino acids responsible for the catalytic differences. The approach produces an enzyme in which more than half of the product is channeled through an alternative pathway. Several (-)-pinene synthase to (-)-camphene synthase amino acid substitutions are necessary before catalysis is significantly altered
Schwab, W.; Williams, D.C.; Davis, E.M.; Croteau, R.
Mechanism of monoterpene cyclization: Stereochemical aspects of the transformation of noncyclizable substrate analogs by recombinant (-)-limonene synthase, (+)-bornyl diphosphate synthase, and (-)-pinene synthase