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Without the aid of traditional healers like this man in India administering fish medicine to a patient in 2008, modern medicine would lack many of its most vital drugs.

An ethnobotanist learns about medicinal plants through a tribe: what kinds of healing properties the plant has, what conditions it's used to treat, what part of the plant is used and how it's prepared. He or she collects samples for analysis, and it's here that the process is transferred from the realm of anthropology to that of modern chemistry. It's the synthetic chemist's challenge to isolate the active ingredients in the plant. More importantly, chemists must figure out how to synthetically reproduce these natural ingredients.

The most basic level of deriving medicines from plants is extraction -- simply removing essential oils from the plant and concentrating them. This yields unreliable results, however, as concentrations aren't guaranteed. One bottle of medicine could be impotent, while another packs a dangerously powerful wallop. Synthetic chemists must take deriving medicine from plants to its highest level by producing compounds that mimic the molecular structure found in the plants. Without this necessary step, plant-derived medicines would have to be made from the plants directly, an expensive and often Herculean task.

This has been done successfully many times over in the history of synthetic chemistry. Quinine, used to treat malaria, is based on cinchona bark and digoxin, a treatment for heart conditions, comes from foxglove [source: Lee]. Morphine is another sterling example. This alkaloid found in poppy plants was isolated in the 19th century and synthesized in 1874 into diacetylmorphine, sold commercially by the Bayer Company from 1898 to 1910 under the trade name "Heroin" as a nonaddictive alternative to morphine [source: VCU]. While that product may have unleashed a scourge on humanity, synthesized morphine and its cousin codeine have eased the suffering of millions of patients since they were introduced into medicine.

Bayer's also responsible for another widespread medicine that traces its lineage back to plants: aspirin. In the 19th century, chemists isolated the natural compound salicin from willow bark. This bark has been used in traditional medicine at least as long as the time of Hippocrates, who prescribed it as a fever-reducer and anti-inflammatory [source: University of Maryland]. Salicin was synthesized into acetylsalicylic acid (aspirin).

Plants also play a role in modern chemistry beyond lending their molecular structure to synthesized drugs. Medicinal and nonmedicinal plants can provide chemists with enzymes and other structures that can act as catalysts in the production of synthetic compounds. Whole cells can be used as a "biological factory," producing ingredients needed in chemical synthesis and providing a stable environment for the chemical reactions needed to create them [source: Kutney].

It's clear that as removed as it is from the ancient lineage of traditional medicine, modern pharmacology owes a great deal to plants.

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