3,5,6-Trichloro-2-pyridinol (TCPy) is the main degradation product of the herbicide Triclopyr and the insecticides Chlorpyrifos and Chlorpyrifos-methyl.

Physicochemical Properties

Molecular Formula	C5H2CL3NO
Molecular Weight	198.43
Exact Mass	196.92
CAS #	6515-38-4
Related CAS #	37439-34-2 (hydrochloride salt)
PubChem CID	23017
Appearance	White to off-white solid powder
Density	1.7±0.1 g/cm3
Boiling Point	325.0±37.0 °C at 760 mmHg
Melting Point	328-330ºC
Flash Point	150.4±26.5 °C
Vapour Pressure	0.0±0.7 mmHg at 25°C
Index of Refraction	1.617
LogP	2.16
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	1
Rotatable Bond Count	0
Heavy Atom Count	10
Complexity	243
Defined Atom Stereocenter Count	0
InChi Key	WCYYAQFQZQEUEN-UHFFFAOYSA-N
InChi Code	InChI=1S/C5H2Cl3NO/c6-2-1-3(7)5(10)9-4(2)8/h1H,(H,9,10)
Chemical Name	3,5,6-trichloro-1H-pyridin-2-one
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

ADME/Pharmacokinetics	Metabolism / Metabolites 3,5,6-Trichloro-2-pyridinol is a known human metabolite of Chlorpyrifos-oxon and Chlorpyrifos.
References	[1]. Novel gene clusters and metabolic pathway involved in 3,5,6-trichloro-2-pyridinol degradation by Ralstonia sp. strain T6. Appl Environ Microbiol. 2013 Dec;79(23):7445-53.
Additional Infomation	3,5,6-trichloro-2-pyridinol is a hydroxypyridine that is pyridin-2-ol substituted by chloro groups at positions 3,5 and 6. It is a metabolite of the agrochemical chlorpyrifos. It has a role as a human urinary metabolite and a human xenobiotic metabolite. It is a chloropyridine and a hydroxypyridine. It is a tautomer of a 3,5,6-trichloropyridine-2-one. 3,5,6-Trichloro-2-pyridinol has been reported in Bos taurus and Euglena gracilis with data available.

Solubility Data

Solubility (In Vitro)

DMSO: 32.5 mg/mL (163.79 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 3.25 mg/mL (16.38 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 32.5 mg/mL clear DMSO stock solution to 400 μL of PEG300 and mix evenly; then add 50 μL of Tween-80 to the above solution and mix evenly; then add 450 μL of 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: ≥ 3.25 mg/mL (16.38 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 32.5 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	5.0396 mL	25.1978 mL	50.3956 mL
	5 mM	1.0079 mL	5.0396 mL	10.0791 mL
	10 mM	0.5040 mL	2.5198 mL	5.0396 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.