Paclobutrazol is a triazole-containing plant growth retardant that can inhibit gibberellin biosynthesis. Paclobutrazol also has antifungal activity. Paclobutrazol inhibits the synthesis of abscisic acid and induces cold tolerance in plants. Paclobutrazol is extensively usedto study the role of gibberellins in plant biology.

Physicochemical Properties

Molecular Formula	C15H20CLN3O
Molecular Weight	293.79
Exact Mass	293.129
CAS #	76738-62-0
Related CAS #	(Rac)-Paclobutrazol-15N3;2642083-16-5;Paclobutrazol-d4
PubChem CID	616765
Appearance	White to off-white solid powder
Density	1.2±0.1 g/cm3
Boiling Point	460.9±55.0 °C at 760 mmHg
Melting Point	165-166°C
Flash Point	232.6±31.5 °C
Vapour Pressure	0.0±1.2 mmHg at 25°C
Index of Refraction	1.580
LogP	2.99
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	3
Rotatable Bond Count	5
Heavy Atom Count	20
Complexity	300
Defined Atom Stereocenter Count	0
InChi Key	RMOGWMIKYWRTKW-UHFFFAOYSA-N
InChi Code	InChI=1S/C15H20ClN3O/c1-15(2,3)14(20)13(19-10-17-9-18-19)8-11-4-6-12(16)7-5-11/h4-7,9-10,13-14,20H,8H2,1-3H3
Chemical Name	1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)pentan-3-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 Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture.
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

ln Vitro

In mature mustard seeds, paclobutrazol (foliar spray, 5–20 μg/mL) increases total soluble sugars, carbohydrates, protein, and independent dosages. The growth of fungi, including Sirococcus clavigignenti, juglandacearum, and Ceratocystis fagacearum, is inhibited by paclobutrazol (0-19.8 μg·AI/mL) [2]. Tomato seedlings treated with paclobutrazol (5-100 μg/mL, 7–21 days) have higher quality and are resistant to early blight [3].

Additional Infomation

1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pentan-3-ol is a member of the class of triazoles that is 2,2-dimethylpentane that is substituted at positions 2, 3, and 5 by hydroxy, 1,2,4-triazol-1-yl, and p-chlorophenyl groups, respectively. It is a member of triazoles, a member of monochlorobenzenes and a secondary alcohol.

Solubility Data

Solubility (In Vitro)

DMSO : 250 mg/mL (850.95 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.08 mg/mL (7.08 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 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 20.8 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. Solubility in Formulation 2: ≥ 2.08 mg/mL (7.08 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in 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 20.8 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 2.08 mg/mL (7.08 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (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 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.4038 mL	17.0190 mL	34.0379 mL
	5 mM	0.6808 mL	3.4038 mL	6.8076 mL
	10 mM	0.3404 mL	1.7019 mL	3.4038 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.