There are now over 120 known glucosinolates that have been found in many hundreds of species of plants, and there are many hundreds of primary references on the subject of glucosinolates from plants. This literature started over a hundred years ago, and over the last 50 years it has become very diffuse—spread amongst the botanical, agricultural, medical, biochemical, and chemical literature. We initially attempted to sort and categorize all of this information for reasonably easy lookup and retrieval because WE wanted such a reference for our own use. We also attempted to modernize synthesis of the literature on these compounds in which considerable interest has developed in recent years.

  Does it describe a new discovery or a new methodology that’s useful to others?

It does not describe a new discovery, but it provides a comprehensive survey of the chemical structures of all known glucosinolates and the plant families from which they have been isolated. It provides a single source of their chemical structure, their trivial or common names, and is the first systematic effort to classify these compounds into families according to their structural similarities. It also discusses the status of scientific understanding of the synthesis, biosynthesis, and ecological importance of glucosinolates and their conversion to isothiocyanates and other products by an enzyme found in both plants and human gastrointestinal systems. In so doing, we have attempted to highlight some of the more beneficial aspects of these compounds that have come to light in recent years (e.g. their therapeutic and prophylactic properties as a nutritional or "functional" component of diets). These exciting positive attributes are in sharp contrast to the "antinutritional" properties that have been the focus of much previous work since a small number of these compounds were demonstrated to have goitrogenic potential, many years ago.

This was actually a labor of love and of stubbornness, which grew from a realization that there had been no comprehensive review of the known literature on glucosinolates since 1983, and that one was needed by those of us in the field who wanted to be able to readily determine: (a) which plants produced what glucosinolates, (b) what were the glucosinolates’ structures, (c) what were their common and chemical names, and (d) who did the original isolation and/or discovery work. Since this work was not directly supported by any of our grants, it actually consumed four consecutive Christmas vacations and much time in between—spending much of that time on a drafting table in my basement that was dedicated to its assembly. Paul Talalay and I interested Amy Zalcmann, who was then a Johns Hopkins undergraduate, in helping us on the project. The initial assembly involved construction of the tables for the use of those in our laboratory. It then became clear to us that it was selfish to not share these data with the relatively small community of scientists interested in glucosinolate biology and chemistry. Posting it on a website was an option, but not one that we embraced, so we decided to round it out as a scholarly review, and see if a journal was interested in wrestling with the unwieldy table(s). Norman Lewis (Editor, Phytochemistry) was, and we thank him.

  Could you summarize the significance of your paper in layman’s terms?

Glucosinolates are a diverse family of water-soluble phytochemicals (metabolites that plants produce not as structural or energy-storage compounds, but for defensive or competitive purposes). Glucosinolates are relatively non-reactive sulfur-containing molecules, which upon chewing the plants that contain them, are converted to compounds called isothiocyanates. These isothiocyanates can have very potent cancer chemoprotective attributes, as well as being fungicidal, bactericidal, and allelopathic (inhibiting the growth of plants which would otherwise share a given habitat). We have also just shown that one of the isothiocyanates has potent antibiotic activity against Helicobacter pylori, the causative agent of most ulcers and a risk factor for stomach cancer. At least 16 families of higher plants produce glucosinolates. The best known of these families is the Brassica or cruciferous family, which contains vegetables that are important components of the cuisines of many countries. There is thus considerable impetus to understand more about the synthesis, metabolism, and distribution of these compounds.

Jed W. Fahey
Faculty Research Associate
Johns Hopkins University
School of Medicine
Department of Pharmacology & Molecular Sciences
Brassica Chemoprotection Laboratory
Baltimore, Maryland, USA

Paul Talalay, MD
Johns Hopkins University
School of Medicine
Department of Pharmacology & Molecular Sciences
Baltimore, Maryland, USA