Abstract
This personal account summarizes our ongoing work on the bioorganic chemistry of diverse
microbial terpenoids. First, two selected total syntheses that were recently completed
in our group are presented. We then show how the fundamental technique for our analytical
work, closed-loop stripping apparatus (CLSA) in combination with gas chromatography/mass
spectrometry (GC/MS), can be used to efficiently identify volatile natural products
from various bacteria and fungi. The largest compound class among these volatiles
is the terpenes. The CLSA technique can also be successfully applied to study interesting
problems of the sometimes puzzling biosynthetic pathways towards terpenes. For this
purpose we have developed two new CLSA-based methods, the first using 13C-labeled precursors in feeding studies which allow for structure elucidations of
microgram amounts of terpenes in complex headspace mixtures, and the second, a genome-mining
approach via heterologous expression for the rapid chemical characterization of bacterial
terpene cyclases. Recent developments in our laboratory include mechanistic investigations
based on enzyme structural data in combination with site-specific mutations of terpene
cyclases.
1 Introduction
2 Total Synthesis of Glaciapyrrole A and Tricho-acorenol
3 Feeding Experiments with Deuterated Precursors
4 The IspH Reaction
5 Feeding Experiments with 13C-Labeled Precursors
6 Genome Mining and Closed-Loop Stripping Apparatus
7 Conclusion
Key words
biosynthesis - microorganisms - natural products - terpenoids - volatiles
