Many natural substances possess interesting characteristics, and can form the basis of new active compounds in medicine. Terpenes, for example, are a group of substances, some of which are already used in therapies against cancer, malaria or epilepsy. They are found as fragrances in cosmetics or as flavorings in food, and form the basis of new medications: Terpenes are natural substances that occur in plants, insects and sea sponges. They are difficult to produce synthetically. However, chemists are now introducing a new method of synthesis.