diazonamide-a and azaspiracid

Over the course of the past half century, the structural elucidation of unknown natural products has undergone a tremendous revolution. Before World War II, a chemist would have relied almost exclusively on the art of chemical synthesis, primarily in the form of degradation and derivatization reactions, to develop and test structural hypotheses in a process that often took years to complete when grams of material were available. Today, a battery of advanced spectroscopic methods, such as multidimensional NMR spectroscopy and high-resolution mass spectrometry, not to mention X-ray crystallography, exist for the expeditious assignment of structures to highly complex molecules isolated from nature in milligram or sub-milligram quantities. In fact, it could be argued that the characterization of natural products has become a routine task, one which no longer even requires a reaction flask! This Review makes the case that imaginative detective work and chemical synthesis still have important roles to play in the process of solving nature's most intriguing molecular puzzles.

Topics: Biological Products; Crystallography, X-Ray; Heterocyclic Compounds, 4 or More Rings; History, 20th Century; History, 21st Century; Humans; Magnetic Resonance Spectroscopy; Marine Toxins; Molecular Structure; Oxazoles; Pharmacognosy; Plant Extracts; Spiro Compounds