Research on Plant Compounds

A crucial aspect in the research on plant constituents is how to localize the compounds of interest. How is a researcher to find the plant containing the right substance with the activity he or she is after? This is often the bottleneck for finding new important natural compounds, but this lack of knowledge can be overcome in several ways:

• by studying the traditional medicine it is possible to learn which plants have been known to act against certain diseases. Thus, one can obtain an idea where to look for if one is after a specific activity. By using selective assay reactions, it is possible to pinpoint and isolate the compound responsible for the activity.

• testing plants that are related to a species, known to contain an active substance, may lead to the discovery of more compounds sharing (or even improving) this activity.

• by taking a closer look at the purpose for which these compounds are synthesized by the plant.In the past, scientists called the often highly complex structures that weren't directly involved in the plant's primary metabolic processes for "secondary". As if these plants were doing so much effort, just to synthesize something that wasn't of any importance to them! Nowadays, we more and more start to understand why these so-called secondary metabolites are formed by plants. So, by studying the physiological role of these compounds and the benefits of them to the plants by which they are synthesized, we can obtain an idea of what kind of biological activity may be hidden. E.g., investigation of plant-insect interactions may lead to the discovery of compounds that have a deterrent or toxic effect to these (and possibly other) insects. Plant-plant interactions also exist. These can be of importance in the development of natural growth inhibitors or herbicides.

Another important research issue is the study of a plant compound's biosynthetical pathway. By localization of those steps in biosynthesis, potentially susceptible for steering or alteration by using molecular techniques, it may be possible to increase the yield of the final product, or to alter its character or molecular structure. In this way, a whole new range of derivatives may be obtained, that may prove to be useful as e.g., pharmaceuticals. In this respect, it is important to consider that biodiversity in general not only comprises a rich variety in chemical substances, but also an enormous potential in all kinds of biosynthetical enzymes and genes that may be used in the process of creating new compounds. Science has only just begun to unravel this area of new opportunities.