Cyclosporin B

• CAT Number: R010263
• CAS Number: 63775-95-1
• Molecular Formula: C61H109N11O12
• Molecular Weight: 1188.6
• Purity: 97%
• Synonyms: Ala2-cyclosporine; Antibiotic S 7481F2
• Appearance: White Powder
• Storage: -20°C
• Analysis method: HPLC
• InChIKey: UCOQITKXMNKTKF-MXGZYYNMSA-N

Cyclosporin B, is a dihydroxylated metabolite of cyclosporin A (CsA). Cyclosporin B (M-26) and other cyclosporin metabolites have been found to have lower (<10%) immunosuppressant activity than cyclosporin A (CsA). Cyclosporin B and other metabolites have been isolated and characterized but do not appear to have been extensively studied.

Cyclosporin B (and other cyclosporin A (CsA) metabolites) have lower immunosuppressant activity but most likely operate under the same mechanism as cyclosporin A (CsA) described below.
Cyclosporin A (CsA) immunosuppressant activity stems from its ability to prevent T-cell activation by blocking specific cytokine transcription genes. After entering a T-cell, cyclosporin A (CsA) associates with ubiquitous cytosolic proteins called cyclophilins which aid in protein folding. Cyclosporin A (CsA) : cyclophilin complexes together bind calcineurin, (another cytosolic protein) effectively blocking the pathway to IL-2 gene transcription and T-cell activation.

Reference

Stiller, C. R., MD, and R. A. Ulan, MD. /Cyclosporin A: A Powerful Immunosuppressant./Canadian Medical Association 126 (1981): 1041-046. www.ncbi.gov. Web. 27 Aug. 2012.

Crabtree, G. R., J. Nourse, and L. Timmermann. /The Mechanism of Action of Cyclosporin A and FK506./ Clinical Immunology and Immunotherapy (1996): 40-45.www.ncbi.gov. Web. 27 Aug. 2012.

Wang, Paul C. et. al. /Isolation of 10 Cyclosporine Metabolites from Human Bile./ Drug Metabolism and Disposition 17.3 (1989): 292-96. Nih.gov. Web. 28 Oct. 2013.

Copeland, Kenneth R. /Immunosuppressive Activity of Cyclosporine Metabolites Compared and Characterized by Mass Spectrometry and Nuclear Magnetic Resonance./Clinical Chemistry 36.2 (1990): 225-29. Web. 28 Oct. 2013.

Matsuda, Staoshi. /Mechanisms of Action of Cyclosporine./ Immunopharmacology 47 (2000): 119-25. Elsevier. Web. 28 Oct. 2013.