This series of lectures was delivered at the 29th meeting of the
Phytochemical Society of North America, held at the University of
British Columbia in Vancouver, B. C., Canada on June 16th-20th, 1989.
Topics concerning terpenoids, consisting of isoprene units, are now so
numerous that a judicious selection for a relatively limited symposium
was difficult. We were able to assemble, however, a potpourri of reviews
on topical areas of terpenoid chemistry, biochemistry and biology, by
scientists who are making exciting contributions and whose work points
the way to significant future research. Because of the importance of
terpenoids in the life of plants, and indeed in all living organisms, a
periodical review of the mevalonic acid pathway and of the subsequent
biochemical events leading to the biosynthesis of isoprenoids needs no
justification. Life, as we know it, would not be possible without the
ability of living organisms to employ this metabolic sequence which
proceeds from condensations of three molecules of acetyl-CoA and
terminates with the elaboration of the terpenoid precursors, isopentenyl
pyrophosphate and dimethylallyl pyrophosphate. In addition to producing
obviously essential compounds that are partially or completely of
isoprenoid origin (Fig. 1), such as hormones, photosynthetic pigments,
compounds involved in electron transport in respiration and in
photosynthesis, oxidative enzymes and membrane components, plants
elaborate thousands of novel terpenoids, many of which do not as yet
have identifiable physiological, biochemical or even ecological roles,
e. g. the cardenolides, ecdysones or saponins.
