Medicinal plants contain many phytochemicals. The study of phytochemistry aims to isolate these compounds, determine their structures, and their levels within the plants.
This is important for several reasons:
1. Quality control of medicinal plants and herbal medicines depends on the levels of the “active compound(s)”. For example different varieties of Artemisia annua contain greatly varying amounts of the antimalarial compound artemisinin (from 0.1% to 1.4%). In some cases it has not been possible to identify a single “active compound” so instead a “marker compound” is used for quality control (for example hypericin in St John’s Wort).
2. Standardisation of herbal medicines: because the levels of phytochemicals vary widely according to the variety and growing conditions of the plant, it is important to define the level of key “active” or “marker” compounds in a particular batch. This is especially important for research such as conducting clinical trials.
3. Drug Development: in some cases it may be desirable to develop and/or chemically modify a single compound to create a better drug.
Isolation methods include various chromatographic techniques:
- TLC = Thin-Layer Chromatography
- HPLC = High-Pressure Liquid Chromatography
- GC = Gas Chromatography
Identification methods include chromatographic and spectroscopic techniques, and chemical tests.
When researching phytochemistry and developing products from medicinal plants, it is crucial to keep in mind ownership of the traditional knowledge and ensure sharing of benefits that arise from these substances. For more information on this, read about Intellectual Property Rights.
The panel overseeing this section of the website consists of the following experts:
Prof Bernard Kiremire, Makerere University, Kampala, Uganda
Prof Oyvind Anderson, Bergen University, Norway
Prof Drissa Diallo, University of Bamako, Mali
Prof Philippe Rasoanaivo, Institut Malgache de Recherches Appliquées, Antananarivo, Madagascar
Prof Thozamile Mabusela, University of the Western Cape, Cape Town, South Africa