Azure C  (Synonyms: Monomethylthionine)

Azure C acts as a tau oligomer modulator and Aβ42 oligomerization inhibitor. It regulates hsp70 ATPase activity, thereby mediating the clearance of tau protein. Azure C reduces the levels of toxic tau oligomers by promoting the formation of non-toxic tau aggregates, rescues neuroblastoma cells from tau oligomer-induced toxicity, and binds to and inhibits Aβ42 oligomerization without suppressing its fibrillization. Azure C is generated via sequential oxidation of methylene blue or Azure B through a horseradish peroxidase-mediated reaction, and accumulates in HRP reaction media. Azure C can be used in studies related to tauopathies, including Alzheimer's disease^[1][2].

Azure C (0.05-10 μM; 16 h) reduces levels of purified preformed tau oligomers in a concentration-dependent manner, with a significant reduction observed at 5 μM^[1].
Azure C (2.5-10 μM; 16 h) significantly reduces levels of purified preformed tau oligomers, without altering total tau levels^[1].
Azure C (5 μM; 16 h preincubation with preformed tau oligomers) reduces the oligomers' toxicity to SH-SY5Y human neuroblastoma cells, resulting in significantly higher cell viability after 24 h of treatment^[1].
Azure C (5 μM; 16 h) reduces levels of toxic tau oligomers from crude tau oligomeric preparations and decreases their hydrophobicity, without disassembling oligomers into monomeric tau^[1].
Azure C (methylene blue:H₂O₂ ratio 1:5-1:50; 120-450+ min) is produced via HRP-mediated oxidation of methylene blue, with yields increasing from 6.4% to 65.6% under single and pulse H₂O₂ addition conditions, respectively, at pH 6.0 and 37 °C^[2].
Azure C (azure B:H₂O₂ ratio 1:3-1:40; 120-360+ min) is produced via HRP-mediated oxidation of azure B, with yields increasing from 16.1% to 66.2% under single and pulse H₂O₂ addition conditions, respectively, at pH 6.0 and 37 °C^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

277.78

C₁₃H₁₂ClN₃S

531-57-7

Solid

Brown to dark green

[Cl-].N=1C2=CC=C(N)C=C2[S+]=C3C=C(C=CC13)NC

Room temperature in continental US; may vary elsewhere.

4°C, protect from light

*In solvent : -80°C, 6 months; -20°C, 1 month (protect from light)

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (protect from light). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

• [1]. Lo Cascio F, et al. Azure C Targets and Modulates Toxic Tau Oligomers. ACS Chem Neurosci. 2018;9(6):1317-1326.  [Content Brief]

  [2]. Viridiana S, et al. Methylene blue and azure B oxidation by horseradish peroxidase: a comparative evaluation of class II and class III peroxidases. Applied Catalysis B: Environmental. Volume 42, Issue 2, 8 May 2003, Pages 213-221.