Macrocyclic compounds are widespread in nature. These are porphyrins (chlorophyll, heme as a part of hemoglobin, Vitamin B12), cyclic peptides (antibiotics gramicidin C, capreomycin, valinomycin, vancomycin, amato, and fallotokcins of death cup amanita (Amanita phalloides) and some toadstools), macrocyclic alkaloids (including tubocurarin–the main component of the Indian poison curare), cyclic ketones and lactones (musk highlight animals), and many others. They play a crucial role in the chemical processes occurring in the environment, in the functioning of living systems. For example, the key role in the implementation of photosynthesis by molecules of chlorophyll involves the formation of supramolecular assemblies, the ordered structure of the photo center that contributes to the multistage charge transfer. Supramolecular interactions in the processes of oxygen transport by hemoglobin causes conformational changes that increase the binding constant of oxygen, such as myoglobin, which is not typical. The B12 vitamin (its active forms are cyanocobalamine, adenosylcobalamine, or cobalamine) possesses a pronounced lipotropic effect, prevents the fatty infiltration of a liver, increases the consumption of oxygen by cells in acute and chronic hypoxia, participates in the processes of transmethylation, hydrogen transfer, activates methionine synthesis, possesses an anabolic effect, increases the immunity, takes part in the synthesis of the purine and pyrimidine bases which are a part of nucleinic acids, necessary for the erythropoiesis process, and actively influences the accumulation of compounds containing sulfhydryl groups in erythrocytes.