The University of Kansas | The University of Kansas |
 |
| Home About Us Research Grant Services |
| "Teaming"
with Possibility:
Timmermann joined the University as University Distinguished Professor and chair of the Department of Medicinal Chemistry for the School of Pharmacy in August. She comes to KU from a 25-year career at the University of Arizona, where she was a Regents’ Professor. Timmermann holds a Bachelor of Science degree in biology from the Universidad Nacional de Cordoba, Argentina, and master's and doctorate degrees in phytochemistry from the University of Texas at Austin. Timmermann’s research of the medicinal qualities of plants and microbes has promising implications both for drug discovery and for identifying chemical interactions of organic compounds. She brings to the University an extensive background in biodiversity prospecting, the science of identifying and utilizing chemical compounds produced by natural organisms. “You have to look in nature,” says Timmermann, “at what we have. The plant is rooted, so it has to protect itself from predators and environmental stress.” Because a plant doesn’t have the ability to flee from a predator, chase after prey, or move to a new habitat in extreme weather conditions, the plant copes with stress by producing various adaptations that can be either anatomical, physiological or chemical compounds to ensure its survival. A plant’s chemical adaptations to stress may involve a large number of compounds produced for specific conditions, to fight infection or parasitism, even to enhance reproduction. Some of these chemical compounds are potential sources of drugs for human health. “We are looking for chemicals that are effective for treatment of cancer, antimicrobials, anti-tuberculosis, women’s health,” says Timmermann. For these and other health issues, naturally occurring chemicals may provide less toxic alternatives to some drugs developed in the laboratory. “All these chemicals exist in nature that a chemist may not dream of in their lab,” she says. A positive lead on a molecule that presents biological activity can be passed on to structural medicinal chemists for further modifications, testing and development. “Twenty-five percent of prescription drugs today have their origin in natural sources,” says Timmermann, who cites antibiotics as well-known examples. Additionally, drugs can be synthesized to replicate or improve naturally produced molecules. Timmermann sees great potential for working with scientists throughout the University community to enhance drug discovery. The interdisciplinary nature of her research can involve areas as diverse as the School of Pharmacy, KU Medical Center and Kansas Biological Survey. Says Timmermann, “Every one of my colleagues is a potential collaborator.” Over the past 13 years Timmermann has served as the principal investigator and project director of an International Cooperative Biodiversity Group studying a variety of Latin American plants and microbes of temperate forests, arid and semi-arid ecosystems that hold promise for the discovery and development of prescription drugs. Plant collections are undertaken in diverse ecosystems such as the cold deserts and steppes of Patagonia and Tierra del Fuego, phytogeographical provinces in Argentina, the hyper-arid desert of Atacama, the semi-arid central Chile, and the drylands of central and western Mexico. Now that she’s in Kansas, Timmermann plans to extend her study of local phytomedicines to the indigenous flora of the area. “Many Kansas plants are used medicinally,” she says. “It will be interesting to study them.” Once a plant species is located in the wild, a necessary amount of above-ground biomass is collected to generate organic extracts. All plant samples are subjected to a battery of biomedical bioassays using several automated, high throughput enzyme assays. When biological activity is detected and confirmed for a sample in at least one screen it is considered a positive lead. Not all leads will produce a drug. In fact, nearly all of the compounds that show promise at an early stage in the development process will fail when evaluated in a more advanced animal model. “The real benefits are in the collaborative interactions established among the participating countries, the databases developed as a result of the project, the technology transfer and the training of students and faculty through active exchange programs,” says Timmermann. When available, local collaborators in the collection areas are contacted and interviewed about plant remedies from the local flora. Not only does this information increase the chance of drug discovery, but also helps insure preservation of cultural knowledge and promotes ecological conservation and economic development. “For thousands of years people have relied on plant extracts and natural organisms to treat disease,” says Timmermann. By documenting the use of these extracts by indigenous peoples, scientists like Timmermann can focus on particular plants and isolate molecules and chemical compounds displaying biological activity for specific illnesses and chronic medical conditions. The study of ancient therapies also has implications for contemporary use of dietary supplements. “People are taking things and we don’t know how they work,” says Timmermann, who notes that the use of herbs and other natural substances as dietary supplements or for medicinal purposes is growing. A single supplement may contain hundreds of chemicals. In an age of high technology and advanced science, there has been little research and scant clinical data is available as to how these dietary supplements might interact with each other or with prescription medications. A large segment of Timmermann’s research is poised to answer these questions and provide an extensive database of knowledge about commonly used medicinal plants. “We need to know what chemicals in these compounds are active, which ones are safe,” she explains. Analyzing and cataloging the vast array of botanicals on the market today is a daunting proposition. According to Timmermann, “each is a lifetime of work and funding.” To start with an area that holds particular interest and potential, Timmermann has devoted in-depth study into natural anti-inflammatory medicines for conditions such as arthritis. Citing recent problems with synthetic drugs, Timmermann says there is great interest in studies of the anti-inflammatory properties of natural compounds such as ginger and turmeric. “These herbs have been used safely for thousands of years as seasonings in food,” she says, noting that they also have a long history of use in both Chinese and Ayurvedic medicine as anti-inflammatories. Defining the efficacy of ginger alone has taken years of research. Timmermann has found that different lots of plant specimens produce different chemistry. She says that when the plant source changes, the chemical composition changes. Each plant may produce a complex array of natural products as adaptations to extreme conditions of heat, desiccation, ultraviolet radiation, and herbivory, not to mention defenses against infectious disease and parasitism. “Because producing chemicals is an adaptive and therefore constantly changing behavior,” explains Timmermann, “we may go back to find more of the same samples to test, and be unable to find the same properties again.” Plants harvested in different areas of the world may display widely divergent chemical properties. Additionally, a particular type of plant may comprise hundreds of varieties. For example, early in her ginger research, Timmermann sought to obtain plant samples from different parts of the world. She soon found in collecting plants from different sources that this seemingly generic botanical comes in about 160 varieties, and that the chemistry of different samples of ginger is notably different from the others. Such findings highlight the need for further study and documentation of the chemical make-up of medicinal plants. Through chemical validation and authentication of botanicals, Timmermann and other scientists like her are creating a library and building a database that will be indispensable to pharmacists as well as chemists. By cataloging botanicals, the properties of the molecules found in them, the interactions of molecules in these compound forms, and the interactions of these botanical compounds with prescription drugs, Timmermann hopes to compile vital information to help pharmacists answer consumers’ questions about the use of dietary supplements and natural remedies. “Pharmacists have the motive, opportunity, and means to play key roles in caring for patients taking, or considering taking, herbal products and other types of alternative medicines,” she says. She plans to share her expertise with KU Pharmacy undergraduates by offering a course designed to teach future pharmacists about the chemistry, pharmacology, toxicology of botanicals as well as their interaction with prescription medications. “By actively assuming responsibility for counseling on appropriate use of botanicals and dietary supplements, pharmacists gain recognition as a source of expert information in this rapidly growing area,” she says. With so many plants and microbes to study and catalog, and so many potential collaborators to work with, Timmermann certainly has her work cut out for her at KU. She’s ready to rise to the challenge, ready to move into her new laboratory space in the Multidisciplinary Research Building on KU’s West Campus, and ready to team up for drug discovery, utilization and conservation of natural resources, economic development and the efficacy of botanicals. “I see myself as a catalyst,” she says. “I’ve been very successful bringing teams together of chemists, ethnobotanists, conservationists, anthropologists, medical doctors, pharmacologists, toxicologists, pharmacokineticists, social scientists. In a way, I speak everybody’s language.” And with the shifting emphasis on botanicals and less toxic chemical compounds for drug discovery and development, her research speaks a language we all need to understand. Higuchi
Biosciences Center |
||
| home about us research grant services search | ||
| Copyright
© 2008 The University of
Kansas Site Index Web credits |
Barbara
Timmermann’s study of plants and microbes is a natural fit for bioscience
research at the University of Kansas. Recent demand for safer and effective
new drugs and increasing public interest in natural remedies are leading
a resurgence in natural products chemistry research. KU is prepared to
take a leading role in this aspect of pharmaceutical research, with Timmermann
acting as a team-builder to facilitate the use of naturally occurring
chemicals in tomorrow’s prescription drugs.