Methylene blue is 3,7-bis(dimethylamino)-phenazathioniumchloride (Urised). The compound occurs as a dark greencrystalline powder with a metallic appearance that is solublein water (1:25) and alcohol (1:65).Methylene blue has weak antiseptic properties that makeit useful for the treatment of cystitis and urethritis. The actionof methylene blue is considered to be bacteriostatic.The compound colors the urine and stool blue green.
Crystallise the chloride from 0.1M 664 2HCl (16mL/g), the crystals are separated by centrifugation, washed with chilled EtOH and diethyl ether, and dried under vacuum. Crystallise it from 50% aqueous EtOH, wash it with absolute EtOH, and dry it at 50-55o for 24hours. It has also been crystallised from *benzene/MeOH (3:1). It has been salted out with NaCl from a commercial concentrated aqueous solution, then crystallised from water, and dried at 100o in an oven for 8-10hours. [Beilstein 27 III/IV 5152.]
A useful inhibitor of cGMP-mediated processes and a useful stain
Biological stain and redox indicator. Inhibits tau filament formation (IC 50 = 1.9 μ M). Also inhibits soluble guanylyl cyclase.
Veterinary Drugs and Treatments
Methylene blue is used primarily for treating methemoglobinemia
secondary to oxidative agents (nitrates, chlorates) in ruminants. It
is also employed occasionally as adjunctive or alternative
for cyanide toxicity.
Intra-operative methylene blue is also being used to preferentially
stain islet-cell tumors of the pancreas
in dogs in order to aid in
their surgical removal or in determining the animal’s prognosis.
green fine crystalline powder
ChEBI: An organic chloride salt having 3,7-bis(dimethylamino)phenothiazin-5-ium as the counterion. A commonly used dye that also exhibits antioxidant, antimalarial, antidepressant and cardioprotective properties.
Toxic by ingestion.
Poison by ingestion,intraperitoneal, intravenous, and subcutaneous routes.Human systemic effects: cyanosis, blood changes.Experimental reproductive effects. Mutation datareported. When heated to decomposition it emits verytoxic fumes of NOx, SOx, and