Chloroquine diphosphate

Description

Chloroquine is an aminoquinoline that is an inhibitor of autophagy and has antimalarial, anti-inflammatory, anticancer, and antiviral activities. Chloroquine inhibits autophagosome-lysosome fusion in HeLa cells when used at a concentration of 100 μM. It is active against the chloroquine-sensitive GC03 strain of P. falciparum (IC₅₀ = 29.2 nM) but has decreased activity against mutant pfcrt P. falciparum (IC₅₀s = 100-150 nM). Chloroquine prevents infection by severe acute respiratory coronavirus 2 (SARS-CoV-2) in Vero cells (EC₅₀ = 1.13 μM) but does not inhibit SARS-CoV replication in the lungs in a mouse model of SARS-CoV infection. It inhibits the growth of human SSC25 and CAL 27 oral squamous cell carcinoma cells (IC₅₀s = 29.9 and 17.3 μM, respectively), as well as A498, SN12C, RXF 393, and 769-P renal cancer cells (IC₅₀s = 16, 62, 81, and 25 μM, respectively). It reduces tumor growth in a CAL 27 mouse xenograft model and a 4T1 mouse allograft model when administered at a dose of 50 mg/kg. Formulations containing chloroquine have been used in the prevention of malaria, as well as the treatment of rheumatoid arthritis and systemic lupus erythematosus (SLE), and have been associated with cardiotoxicity and myopathy.

Chemical properties

White Solid. Chloroquine diphosphate exists as a crystalline solid with a solubility of approximately 10 mg/ml in PBS (pH 7.2).

Originator

Nivaquine,Specia,France,1949

The Uses of Chloroquine diphosphate

Chloroquine diphosphate is a standard antimalarial drug. It is a substrate for MRP in multidrug-resistant cell lines and inhibits the photoaffinity labelling of MRP by the quinoline photoreactive drug IAAQ. Chloroquine is a weak intercalating agent for the treatment of amebiasis, rheumatoid arthritis, discoid lupus erythematosus and systemic lupus erythematosus. Chloroquine diphosphate has also been used to study the role of endosomal acidification in cellular processes such as intracellular TLR signalling. Chloroquine diphosphate is also used to study the role of endosomal acidification in cellular processes such as intracellular TLR signalling. It is also used as a DNA intermediate to dissociate antigen-antibody complexes without denaturing red blood cell antigens. Chloroquine has very high antiviral activity against NiV at concentrations below 20 μM, but very low activity against other viruses.

Manufacturing Process

105 g of 4,7-dichloroquinoline (MP 93 to 94°C) are heated with 200 g of 1- diethylamino-4-aminopentane for 7 hours in an oil bath to 180°C while stirring, until a test portion dissolved in diluted nitric acid does not show a precipitation with sodium acetate solution. The mixture is dissolved in diluted acetic acid and made alkaline by adding sodium lye.
The base is extracted with ether, dried with potassium carbonate, the ether removed by distillation and the residue fractionated. The 4-(5'- diethylaminopentyl-2'-amino)-7-chloroquinoline (BP 212 to 214C/0.2 mm) is obtained. On cooling the compound solidifies crystalline. It melts, recrystallized from benzene, at 88°C. The base combines with phosphoric acid to yield a diphosphate salt.

Therapeutic Function

Antimalarial

General Description

Chloroquine phosphate is a phosphate salt of chloroquine. It belongs to the class of aminoquinoline drugs utilized as antimalarials and amebicides.

Biochem/physiol Actions

Standard anti-malarial drug. Substrate for MRP in multidrug resistant cell line and inhibits photoaffinity labeling of MRP by quinoline-based photoactive drug IAAQ (N-[4-[1-hydroxy-2-(dibutylamino)ethyl]quinolin-8-yl]-4-azidosalicylamide).

storage

Desiccate at RT

References

1) Frieboes et al. (2014), Chloroquine-mediated cell death in metastatic pancreatic adenocarcinoma through inhibition of autophagy; JOP, 15 189 2) Jiang et al. (2010), Antitumor and antimetastatic activities of chloroquine diphosphate in a murine model of breast cancer; Biomed. Pharmacother., 64 609 3) Choi et al. (2014), Chloroquine eliminates cancer stem cells through deregulation of Jak2 and DNMT1; Stem Cells, 32 2309 4) Mulcahy Levy et al. (2014), Autophagy inhibition improves chemosensitivity in BRAFV600E brain tumors; Cancer Discov., 4 773