General Information
We investigate how plants make special chemicals called natural products. These chemicals frequently are used as medicines, either as pure compounds by pharmaceutical industry, or as mixtures in traditional medicines. We use a wide range of biochemical and molecular genetic techniques to understand how selected medicinal plant species make bioactive natural products. A better understanding of the enzymes and underlying genes of plant natural biosynthesis will facilitate the development of improved sources of medicines through metabolic engineering of medicinal plants and heterologous hosts such as yeast and bacteria. Selected natural products are currently being investigated in the laboratory in mature plants and in tissue and cell culture. Ongoing research investigates naphthoquinone biosynthesis in Plumbago indica and Drosophyllum lusitanicum, emetine formation in Psychotria ipecacuanha and morphine biosynthesis in Papaver somniferum and in mammals.

One of our main focuses is on a class of natural products called alkaloids. Alkaloids are pharmacologically active, nitrogen-containing heterocyclic compounds originally believed to be only of plant origin. Since the isolation of the first alkaloid morphine, more than 14,000 structures have been defined. Each species accumulates alkaloids in a unique and defined pattern. Many alkaloid-containing plants are used today as a source of prescription drugs.

For much of human history, plant extracts have been used as ingredients in potions and poisons. In the eastern Mediterranean, use of opium poppy latex (Papaver somniferum) can be traced back at least to 1400 to 1200 B.C. Ancient folks used medicinal plant extracts as purgatives, antitussives, sedatives and treatments for a wide range of ailments from snakebites to fever. Use of medicinal plants then spread westward across Europe. Over the centuries, one of the most important medicinals was opium. Analysis of the individual components of opium led to the identification of morphine. The isolation of morphine in 1806 by the German pharmacist Friedrich Sertuerner gave rise to the study of alkaloids. Alkaloids were originally defined as pharmacologically active, nitrogen-containing basic compounds of plant origin. Alkaloid-containing plants were mankind's original materia medica. Many alkaloids are still in use today as prescription drugs; one of the best known and widely used is the antitussive codeine from the opium poppy. After more than 200 years of alkaloid research, this class of natural products still finds significance in the medical field in the treatment of diseases ranging from cancer potentially through to malaria.