Clemastine (fumarate)

Clemastine is a histamine H1 receptor antagonist (Ki = 0.26 nM). It is selective for the histamine H1 receptor over muscarinic acetylcholine receptors (mAChRs, Ki = 16 nM), as well as over sigma-1 (sigma1) and sigma2 and alpha2A-, alpha2B-, and alpha2C-adrenergic receptors (Kis = 67, 15, 1,365, 691, and 545 nM, respectively). Clemastine (0.12 mg/kg) alone or in combination with the histamine H2 receptor antagonist cimetidine (Cay-18743) reduces ovalbumin-induced bronchial obstruction in ovalbumin-sensitized guinea pigs. It also decreases severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication in SARS-CoV-2-infected Vero E6 cells (EC50 = 0.95 µM) with a 50% cytotoxic concentration (CC50) value of >20 µM. Formulations containing clemastine have been used in the treatment of allergic rhinitis.Formal Name: (2R)-2-[2-[(1R)-1-(4-chlorophenyl)-1-phenylethoxy]ethyl]-1-methyl-pyrrolidine, 2E-butenedioate. CAS Number: 14976-57-9. Molecular Formula: C21H26ClNO . C4H4O4. Formula Weight: 460.0. Purity: >98%. Formulation: (Request formulation change), A crystalline solid. Solubility: DMF: 1.6 mg/ml, DMSO: 2.5 mg/ml, Ethanol: 0.1 mg/ml, PBS (pH 7.2): 0.3 mg/ml. SMILES: ClC1=CC=C([C@@](OCC[C@H]2CCCN2C)(C)C3=CC=CC=C3)C=C1.OC(/C=C/C(O)=O)=O. InChi Code: InChI=1S/C21H26ClNO.C4H4O4/c1-21(17-7-4-3-5-8-17,18-10-12-19(22)13-11-18)24-16-14-20-9-6-15-23(20)2,5-3(6)1-2-4(7)8/h3-5,7-8,10-13,20H,6,9,14-16H2,1-2H3,1-2H,(H,5,6)(H,7,8)/b,2-1+/t20-,21-,/m1./s1. InChi Key: PMGQWSIVQFOFOQ-YKVZVUFRSA-N.