Natural products are compounds that are formed by living systems.[ ] Naturally occurring compounds may fall into two major categories. The first type, primary metabolites, consists of compounds that occur in all cells and play a central role in the metabolism and reproduction of those cells. The second type, secondary metabolites, consists of compounds that are characteristic of a limited range of species and are not directly involved in the normal growth, development, and reproduction of an organism. The latter include antibiotics, toxins, allelochemicals, pheromones, enzyme inhibitors, immunomodulating agents, receptor antagonists and agonists, insecticides, anticancer agents, and growth promoters and many others;[ ] interest in these compounds is still growing. [.]
Zerihun Teklemariam Dame
Ethiopian Rift Valley lakes Microcystis aeruginosa strain antibiotics bioactive metabolites cyanobacterial samples toxic metabolites yanobacterium