Biosynthetic potential of sesquiterpene synthases:: Alternative products of tobacco 5-epi-aristolochene synthase

Nicotiana tabacum (tobacco) 5-epi-aristolochene synthase (TEAS) serves as all useful model for understanding the enzyme mechanisms of sesquiterpene biosynthesis. Despite extensive bio-chemical and structural characterization of TEAS, a more detailed analysis of the reaction product spectrum is lacking. This Study reports the discovery and quantification of several alternative sesquiterpene products generated by recombinant TEAS ill the single-vial GC-MS assay. The combined use of chiral and non-polar stationary phases for gas chromatography separations proved critical for resolving the numerous sesquiterpene products of TEAS for mass spectral analysis and identification. Co-injection Studies with available authentic standards from both synthetic and natural Sources further corroborated the assignment of several compounds., resulting ill an annotated reaction mechanism accounting for their biosynthesis. Moreover, a previously undocumented farnesyl trans-cis isomerization pathway was observed. (c) 2005 Elsevier Inc. All rights reserved.