Extracellular nucleotides (eNTP) occur outside the cytoplasm in the extracellular matrix, were discovered almost 100 years ago in animal cells. These studies showed that the nucleotides are not only building a strand of DNA/RNA or constitute reservoir of energy (eg ATP or GTP) for various biochemical processes, but also may play role in cell growth and development. Extracellular nucleotides are also involved in maintaining homeostasis in the whole animal organism by maintaining adequate blood pressure and immune response.

Brassinosteroids (BR) are hormones displaying high activity in stimulation of plant growth and development. They are present at low concentrations in pollen grains, anthers, seeds, leaves, stems, roots and vegetative tissues undergoing early developmental stages in a broad range of species representing various evolutionary groups. The richest sources of brassinosteroids are pollen grains and immature seeds, whereas leaves and stems contain much lower concentration of these hormones.