Brassinazole (0.5, 1, 5 μM) significantly caused seedling malformation, the morphology of which was similar to that of BR-deficient mutants. Brassinazole causes cress dwarfism, altering leaf morphology such as the characteristic downward curling and dark green appearance of Arabidopsis BR-deficient mutants. However, administration of 10 nM BR reversed dwarfism.

Physicochemical Properties

Molecular Formula	C18H18CLN3O
Molecular Weight	327.81
Exact Mass	327.113
Elemental Analysis	C, 65.95; H, 5.53; Cl, 10.81; N, 12.82; O, 4.88
CAS #	259200-30-1
Related CAS #	Brassinazole;280129-83-1;(2S,3R)-Brassinazole;259200-31-2
PubChem CID	92846669
Appearance	Off-white to light yellow solid powder
LogP	3.6
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	3
Rotatable Bond Count	5
Heavy Atom Count	23
Complexity	369
Defined Atom Stereocenter Count	2
SMILES	C[C@@](C1=CC=CC=C1)([C@H](CC2=CC=C(C=C2)Cl)N3C=NC=N3)O
InChi Key	YULDTPKHZNKFEY-ZWKOTPCHSA-N
InChi Code	InChI=1S/C18H18ClN3O/c1-18(23,15-5-3-2-4-6-15)17(22-13-20-12-21-22)11-14-7-9-16(19)10-8-14/h2-10,12-13,17,23H,11H2,1H3/t17-,18+/m0/s1
Chemical Name	(2R,3S)-4-(4-chlorophenyl)-2-phenyl-3-(1,2,4-triazol-1-yl)butan-2-ol
Synonyms	(2R,3S)-Brassinazole; 259200-30-1; HY-121161C; DA-59487; CS-0647950; (2R,3S)-4-(4-chlorophenyl)-2-phenyl-3-(1,2,4-triazol-1-yl)butan-2-ol
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

Targets	Brassinosteroid (BR) biosynthesis[1]
ln Vitro	The morphology of seedlings significantly resembled that of BR-deficient mutants because to the considerable deformity caused by brassinazole (0.5, 1, 5 μM). Brassinazole induces cress dwarfism, which modifies leaf morphology. For example, Arabidopsis BR-deficient mutants' distinctive downward curling and dark green look. On the other hand, dwarfism is reversed by administering 10 nM BR [1]. Screening for brassinosteroid (BR) biosynthesis inhibitors was performed to find chemicals that induce dwarfism in Arabidopsis, mutants that resembled BR biosynthesis mutants that can be rescued by BR. Through this screening experiment, the compound brassinazole was selected as the most potent chemical. In dark-grown Arabidopsis, brassinazole-induced morphological changes were nearly restored to those of wild type by treatment with brassinolide. The structure of brassinazole is similar to pacrobutrazol, a gibberellin biosynthesis inhibitor. However, in assays with cress (Lepidium sativum) plants, brassinazole-treated plants did not show recovery after the addition of gibberellin but showed good recovery after the addition of brassinolide. These data demonstrate that brassinazole is a specific BR biosynthesis inhibitor. Brassinazole-treated cress also showed dwarfism, with altered leaf morphology, including the downward curling and dark green color typical of Arabidopsis BR-deficient mutants, and this dwarfism was reversed by the application of 10 nM brassinolide. This result suggests that BRs are essential for plant growth, and that brassinazole can be used to clarify the function of BRs in plants as a complement to BR-deficient mutants. The brassinazole action site was also investigated by feeding BR biosynthesis intermediates to cress grown in the light [2].
References	[1]. Preparation of (1,2,4-triazolyl)alkanols as specific inhibitors of brassinosteroid biosynthesis: Japan, JP2000053657. 2000-02-22. [2]. Mode of action of brassinazole: a specific inhibitor of brassinosteroid biosynthesis[M]. 2000. Agrochemical Discovery Chapter 23pp 269-280. DOI: 10.1021/bk-2001-0774.ch023 [3]. Characterization of Brassinazole, a Triazole-Type Brassinosteroid Biosynthesis Inhibitor. Plant Physiol. 2000 May;123(1):93-100.
Additional Infomation	Inhibitors of phytohormone have proven to be useful tools for understanding hormonal function. Recently, brassinolide has been designated as a new class of phytohormone based on the physiological responses of brassinolide-deficient mutants. However, information on other roles of this hormone is limited because studies have been confined to mutants in a limited number of plant species. Therefore, specific inhibitors of brassinosteroid biosynthesis would be valuable tools for investigating their roles at various stages of plant development, such as germination, leaf expansion and flowering. Recent advances in developing brassinosteroid biosynthesis inhibitor, brassinazole (Brz), have shown the importance of brassinosteroids in broad aspects of plant growth and development. This inhibitor induced drastic morphological changes in treated plants, almost identical to those found in brassinosteroid-deficient mutants. The normal phenotype of inhibitor-treated plants could be recovered by the addition of brassinolide. This result suggests that brassinosteroids are essential for plant growth, and that specific brassinosteroid biosynthesis inhibitors can be used to clarify the functions of brassinosteroids in plants when used as a complement to brassinosteroid-deficient mutants. The action site of brassinazole was an oxidative processes from 6-oxo-campestanol to teasterone. [1]

Solubility Data

Solubility (In Vitro)

DMSO: 150 mg/mL (457.58 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 3.75 mg/mL (11.44 mM) (saturation unknown) in 10% DMSO + 40% PEG300 +5% Tween-80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 37.5 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 + to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.0505 mL	15.2527 mL	30.5055 mL
	5 mM	0.6101 mL	3.0505 mL	6.1011 mL
	10 mM	0.3051 mL	1.5253 mL	3.0505 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.