Description

22(S),23(S)-Homobrassinolide are steroidal hormones belonging to the cyclopentane polyhydrophenanthrene class. Unlike animal steroid hormones, they exert their effects not through nuclear receptors but via surface receptors on cell membranes. Brassinosterols were first discovered by Michel in 1970. He extracted a highly active substance from rapeseed pollen that promoted plant stem elongation and cell division, naming it brassinosteroid (Brassins). Given that even minute concentrations of brassinosteroid strongly induce growth and differentiation, and through subsequent molecular genetic studies in Arabidopsis thaliana, it was demonstrated that brassinosteroid functions as a plant hormone.

Chemical Properties

White crystalline powder, active ingredient >95%, melting point 256–258°C. Soluble in methanol, ethanol, tetrahydrofuran, acetone and various other organic solvents. Solubility in water is 5 mg/L.

Uses

22(S),23(S)-Homobrassinolide has been used as a brassinosteroid supplement:

• to study its effects on DNA methylation, callus growth and regeneration in barley.
• to study its effects on cell elongation in Arabidopsis thaliana.
• to study its effects on cell division, root germination and anti-oxidant system enzymes in barley.

Uses

A new class of steroidal phytohormones with high growth-promoting and antistress activity.

Biochem/physiol Actions

22(S),23(S)-Homobrassinolide is a brassinosteroid. It might play a role in the control of plant embryogenesis.

References

[1] A. AZPEITIA. Effect of 22(S),23(S)-homobrassinolide on somatic embryogenesis in plumule explants of Cocos nucifera (L.) cultured in vitro[J]. The Journal of Horticultural Science and Biotechnology, 2003, 44 1: 591-596. DOI:10.1080/14620316.2003.11511669.