The term medicinal plant includes species of healing properties, raw materials of medicines, aromatic and spice plants, etc., with certain exaggeration, all plants, at least, as potential medicinal ones. At the end of the 20th century the great majority of challenges on medicinal plants reflects our present limited knowledge on their chemistry. According to estimation only some 10% of plants have been chemically investigated at all, reflecting the limits of isolation, structure elucidation. Consequently, the evaluation of biodiversity (chemical diversity) of plants should be the starting point of our review. The variation of ingredients at different taxon level (genetic diversity) and variation due to the different ecological factors and to different processing conditions (another point which reflects the analytical approaches) are of growing importance. Chemical, biochemical background is necessary to understand the physiology of plants. Without it, any modern cultivation, biotechnology could be expected.
The increasing importance of herbs and herbal remedies either in the industrialised or developing countries requires more intensive chemical studies. The increasing hazards of environmental pollution (like heavy metals, pesticides, etc.) can also influence the utilisation and quality of medicinal plants. (This point is of special actuality in our region).
In the light of the above mentioned increasing demands for developing even more sophisticated separation and analytical techniques and applying them are of outstanding significance. This is the precondition of discovering new biologically active ingredients against the most vital health problems of human beings. (Problems of phytopharmacology are not discussed her).
Some of the questions to can be well illustrated by examples based upon data available in Hungarian experiences. On the bases of them some priorities can be appointed like the necessity of a) intensifying the isolation and identification of new substances (e.g. for biological testes), of b) introducing new methods for testing the plants and their products, of c) strengthening the quality control of plants, their products and at all levels of plant processing. In all, our andeavour should be to get more complex and reliable information about plants and their products in order to guarantee their safeness and efficaciousness. To draw conclusions international tendencies, requirements of WHO and EU demands, etc. should be taken into account.