Research in natural products has advanced tremendously through the fields of chemistry, life, food and material sciences. Comaprisons of natural products form microorganisms, lower eukaryotes, animals, higher plants and marine organisms are now well documented. Natural products are ubiquitous in our everyday lives. They are active constitutents of many medicines, vitamns, food additives, flavours and fragrances, agrochemicals and pesticides used for plant protection. Most of the natural products are optically active.