Biosynthesis of monoterpenes. Enantioselectivity in the enzymatic cyclization of (+)- and (-)-linalyl pyrophosphate to (+)- and (-)-pinene and (+)- and (-)-camphene

Journal Article · Mon Jul 25 00:00:00 EDT 1988 · J. Biol. Chem.; (United States)

OSTI ID:6829335

Croteau, R; Satterwhite, D M; Cane, D E; Chang, C C

Cyclase I from Salvia officinalis leaf catalyzes the conversion of geranyl pyrophosphate to the stereo-chemically related bicyclic monoterpenes (+)-alpha-pinene and (+)-camphene and to lesser quantities of monocyclic and acyclic olefins, whereas cyclase II from this plant tissue converts the same acyclic precursor to (-)-alpha-pinene, (-)-beta-pinene and (-)-camphene as well as to lesser amounts of monocyclics and acyclics. These antipodal cyclizations are considered to proceed by the initial isomerization of the substrate to the respective bound tertiary allylic intermediates (-)-(3R)- and (+)-(3S)-linalyl pyrophosphate. ((3R)-8,9-14C,(3RS)-1E-3H)Linalyl pyrophosphate (3H:14C = 5.14) was tested as a substrate with both cyclases to determine the configuration of the cyclizing intermediate. This substrate with cyclase I yielded alpha-pinene and camphene with 3H:14C ratios of 3.1 and 4.2, respectively, indicating preferential, but not exclusive, utilization of the (3R)-enantiomer. With cyclase II, the doubly labeled substrate gave bicyclic olefins with 3H:14C ratios of from 13 to 20, indicating preferential, but not exclusive, utilization of the (3S)-enantiomer in this case. (3R)- and (3S)-(1Z-3H)linalyl pyrophosphate were separately compared to the achiral precursors (1-3H)geranyl pyrophosphate and (1-3H)neryl pyrophosphate (cis-isomer) as substrates for the cyclizations. With cyclase I, geranyl, neryl, and (3R)-linalyl pyrophosphate gave rise exclusively to (+)-alpha-pinene and (+)-camphene, whereas (3S)-linayl pyrophosphate produced, at relatively low rates, the (-)-isomers. With cyclase II, geranyl, neryl, and (3S)-linalyl pyrophosphate yielded exclusively the (-)-isomer series, whereas (3R)-linalyl pyrophosphate afforded the (+)-isomers at low rates.

• Research Organization: Washington State Univ., Pullman (USA)
• OSTI ID: 6829335
• Journal Information: J. Biol. Chem.; (United States), Vol. 263:21
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CYCLASES
BIOCHEMICAL REACTION KINETICS
TERPENES
BIOSYNTHESIS
CARBON 14 COMPOUNDS
DOUBLE LABELLING
HERBS
ISOTOPE RATIO
PLANTS
PYROPHOSPHATES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ENZYMES
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LABELLING
LYASES
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
REACTION KINETICS
SYNTHESIS
550201* - Biochemistry- Tracer Techniques