Description

Epibrassinolide is a brassinosteroid that can be isolated from various plants and has been shown to decrease toxicity and stimulate healthy plant growth in plants under stress. Epibrassinolide is also reported to be a potential apoptotic inducer in various cancer cells without affecting the non-tumor cell growth. It has also been shown to protect neuronal PC12 cells from 1-methyl-4-phenylpyridinium-induced oxidative stress and consequent apoptosis in dopaminergic neurons.

Chemical Properties

White Solid

Chemical Properties

The solubility of epibrassinolide in ethanol and DMSO is approximately 3 mg/ml and approximately 5 mg/ml in DMF.

Uses

A plant growth stimulant

Uses

Epibrassinolide has been used:

• in Murashige and Skoog (MS) medium to study the cotyledon and shoot length response of Cappelle-Desprez (rht8) and RIL6 (Rht8) plants towards it
• in callus-inducing medium for callus induction
• to induce the expression of the gene leaf inclination 2 (LC2) in rice sampling

Definition

ChEBI: 24-epi-brassinolide is a 2alpha-hydroxy steroid, a 3alpha-hydroxy steroid, a 22-hydroxy steroid, a 23-hydroxy steroid and a brassinosteroid.

Synthesis

2.06 g (3.70 mmol) of 2,3-dipropionyloxy-24S-ethyl-5-cholest-22-en-6-one (V) was dissolved in 100 ml of dichloromethane, 8.0 g (31.08 mmol) of m-chloroperoxybenzoic acid was added and the mixture was stirred at room temperature for 15 days. Then 8.0 g of powdered calcium hydroxide was added, stirred for 1 hour and filtered, the solvent was removed by vacuum distillation and the crude product was obtained. This crude product was refined by silica gel column chromatography (benzene:ethyl acetate 30:1 to 15:1) to obtain 0.85 g (39.0%) of (22R, 23R, 24S)-2,3-dipropionyloxy-22,23-epoxy-B-homo-7-oxa-5-soylestan-6-one [Compound (I)], i.e., (1R, 3aS, 3bS, 6aS, 8S , 9R, 10aR, 10bS, 12aS)-1-[(1S)-1-[(2R,3R)-3-[(1S)-1-ethyl-2-methylpropyl]-2-oxiranyl]ethyl]hexadecahydro-10a,12a-dimethyl-8,9-bis(1-oxopropoxy)-6H-benzo[c]indeno[5,4-e]oxazan-6-one] also known as propionyl brassinolide.

Metabolic pathway

Two isomeric metabolites, 25-b- and 26-b-D- glucopyranosyloxy-24-epi-brassinolides, are formed in tomato cell suspension cultures with endogenously applied 24-epi-brassinolide. The two-step metabolic process involves hydroxylation of the side chain at C25 and C26, respectively, followed by glucosidation of the newly formed hydroxyl groups. The ratio between both metabolites is altered by in vivo treatment of the cell cultures with various cytochrome P-450-specific inhibitors, indicating the involvement of two different enzyme systems. Biosynthetically prepared 25-hydroxy-24-epi-brassinolide, reapplied to the cell cultures, is exclusively glucosylated at the 25- hydroxyl group, strongly suggesting regiospecificity of the corresponding glucosyltransferase.

References

[1] N. SONDHI. Isolation of 24-epibrassinolide from leaves of Aegle marmelos and evaluation of its antigenotoxicity employing Allium cepa chromosomal aberration assay[J]. Plant Growth Regulation, 2008, 15 1: 217-224. DOI: 10.1007/s10725-007-9242-7
[2] PINAR OBAKAN. SILAC-Based Mass Spectrometry Analysis Reveals That Epibrassinolide Induces Apoptosis via Activating Endoplasmic Reticulum Stress in Prostate Cancer Cells.[J]. PLoS ONE, 2015: e0135788. DOI: 10.1371/journal.pone.0135788
[3] JULIE CARANGE. 24-Epibrassinolide, a Phytosterol from the Brassinosteroid Family, Protects Dopaminergic Cells against MPP-Induced Oxidative Stress and Apoptosis.[J]. Journal of Toxicology, 2011, 2011: 392859. DOI: 10.1155/2011/392859