ABSTRACT
References ......................................................................................................................................346
Compounds present in plants can be divided into three groups [1,2]. The rst group consists of substances occurring in all plant cells and playing a fundamental role in both metabolism and cell reproduction. Such compounds as nucleic acids, common amino acids, and saccharides belong to this group. Generally, this group of metabolites are called primary metabolites [3]. Substances used in the building of plant cell structure are present in the second group of metabolites. Substances characteristic for a limited number of specic plants constitute the third group of metabolites, which are called secondary metabolites [4,5]. Most primary metabolites manifest their biological activity within cells or organs in connection with reproduction. Secondary metabolites are also interesting because of their activity on other organisms [6,7].
