The title of this talk is a word play on what the American poet, Ogden Nash, wrote: “Candy is Dandy, but Liquor is Quicker. “ This presentation explores one of nature’s most fascinating paradoxes: molecules that plants evolved as weapons of chemical warfare have become, for humans, a source of irresistible pleasure. Because plants cannot escape their predators, they developed sophisticated chemical defenses millions of years ago. These include compounds that repel, sicken, or kill would-be attackers, whether insects, fungi, or mammals. Capsaicin, the fiery molecule in chili peppers, binds to pain receptors and produces a burning sensation strong enough to discourage most animals. Yet birds, unaffected by this signal, spread the seeds of plants over long distances. Black pepper’s sharpness comes from the alkaloid piperine, a natural antifungal and insect deterrent. Herbs such as basil, oregano, and thyme are rich in volatile terpenes and phenolic compounds that act as antimicrobials and pesticides. Even cinnamon owes its warm, distinctive character to cinnamaldehyde, a powerful antifungal compound concentrated in the tree’s bark.

The human story is even more remarkable. Rather than rejecting these painful and pungent defenses, our species learned to enjoy them. The mild burning of chili, the sharpness of pepper, or the aromatic lift of herbs became pleasurable sensations, in part because many of these compounds benefit health as antioxidants, anti-inflammatories, or antimicrobials. What began as a deterrent thus became an attraction, woven into cuisine, medicine, and culture across the globe.

This transformation from plant survival strategy to human culinary tradition reveals the profound interplay between chemistry, evolution, and culture. I hope to explain how defensive molecules, once meant to harm, became agents of delight, binding together science, flavor, and human connection in every meal we share. I will also describe how to use spices to achieve the most pleasure when we cook with them.

About the Speaker

A pioneer in the use of lasers to study chemical reactions at the molecular level, Marguerite Blake Wilbur Professor Richard N. Zare pursues diverse theoretical and experimental interests in physical chemistry and nanoscale chemical analysis. The Zarelab has made a broad impact in analytic chemistry with development of laser-induced fluorescence to study reaction dynamics, and seminal contributions to understanding of molecular collision processes. The group continues to invent tools and measurement techniques to study phenomena from reaction in microdroplets to drug delivery.

Born in 1939 in Cleveland, Ohio, Professor Zare trained in physical and analytical chemistry at Harvard University (B.A. 1961, Ph.D. 1964). His doctoral study under Professor Dudley Herschbach explored photodissociation dynamics. After faculty positions spanning chemistry at the Massachusetts Institute of Technology, chemistry, physics and astrophysics at the University of Colorado, and chemistry at Columbia University, he joined the Stanford chemistry faculty in 1977. He has taught an introductory chemistry class every year since. As a Howard Hughes Medical Institute Professor since 2006, Professor Zare has also developed a course introducing undergraduates to hands-on interdisciplinary research, combining physics, and biology to explore how living systems use molecular interactions with light for vision, photosynthesis and more. Professor Zare served as chair of the Department of Chemistry from 2005 to 2011, and has helped to guide scientific policy as chairman of several national and international science boards. His dedication to research and teaching has been recognized in many awards, including the National Medal of Science, the Wolf Prize in Chemistry, and the Presidential Award for Excellence in Science, Mathematics, and Engineering Mentoring. Among other honors, Professor Zare is a member of the National Academy of Sciences, the American Academy of Arts and Sciences, and the American Philosophical Society. He has also received 11 honorary doctorates.

Current research in the Zarelab explores wide-ranging questions in physical and analytical chemistry, from the study of elementary chemical reactions to chemical analysis of extraterrestrial materials. The major focus of these efforts is chemical analysis on the nanoscale. The team has devised tools and techniques to examine molecules in extremely tiny volumes – the volumes characteristic of what is found in heterogeneous structures in mineral samples or in the contents of cells and subcellular compartments. Group members have also made contributions to the chemical analysis of liquid samples separated using a capillary format by electrophoresis or electrochromatography. Some “firsts” include the use of cavity ring-down spectroscopy to analyze trace species in solution, development of detectors for capillary electrophoresis based on the techniques of laser-induced fluorescence, and CCD imaging, and the use of mass spectrometric imaging of tissue samples by means of desorption electrospray ionization.

Please visit the Zarelab website to learn more:  http://web.stanford.edu/group/Zarelab/