9-methyl-3-(2H-1,2,3,4-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one

• ChemBase ID: 763
• Molecular Formular: C10H8N6O
• Molecular Mass: 228.21012
• Monoisotopic Mass: 228.07595891
• SMILES: O=c1n2c(ncc1c1n[nH]nn1)c(ccc2)C
• Canonical SMILES: Cc1cccn2c1ncc(c2=O)c1n[nH]nn1
• InChI: InChI=1S/C10H8N6O/c1-6-3-2-4-16-9(6)11-5-7(10(16)17)8-12-14-15-13-8/h2-5H,1H3,(H,12,13,14,15)
• InChIKey: HIANJWSAHKJQTH-UHFFFAOYSA-N

NAMES AND DATABASE IDS

Names

• IUPAC name: 9-methyl-3-(2H-1,2,3,4-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one
• IUPAC Traditional name: pemirolast
• Brand Name: Alamast
• Synonyms: Pemirolastum [INN-Latin]; Pemirolast Potassium; Pemiroplast Potassium; Pemirolast

Database IDs

• CAS Number: 100299-08-9
• PubChem SID: 46509034; 160964226
• PubChem CID: 57697

CALCULATED PROPERTIES

JChem

• Acid pKa: 5.7956777
• H Acceptors: 5
• H Donor: 1
• LogD (pH = 5.5): 1.2869623
• LogD (pH = 7.4): 0.1722324
• Log P: 1.4587069
• Molar Refractivity: 63.3503 cm^3
• Polarizability: 21.851652 Å^3
• Polar Surface Area: 87.13 Å^2
• Rotatable Bonds: 1
• Lipinski's Rule of Five: true

ALOGPS 2.1

• Log P: 0.13
• LOG S: -2.69
• Solubility (Water): 4.62e-01 g/l

PROPERTIES

Physical Property

• Hydrophobicity(logP): 0

DETAILS

DrugBank - DB00885

• Drug Groups: approved
• Description: Pemirolast potassium is a slightly yellow powder that is soluble in water. It is a mast cell stabilizer that acts as an antiallergic agent. As an ophthalmic aqueous sterile solution, pemirolast is used for the prevention of itching of the eyes caused by allergies such as hay fever, and allergic conjunctivitis. Pemirolast is potentially useful for prophylaxis of pulmonary hypersensitivity reactions to drugs such as paclitaxel.
• Indication: For the prevention of itching of the eyes caused by allergies such as hay fever, and allergic conjunctivitis
• Pharmacology: Pemirolast is used for the prophylactic treatment of itching of the eye associated with allergic conjunctivitis. Pemirolast potassium is a mast cell stabilizer that inhibits the in vivo Type I immediate hypersensitivity reaction. Pemirolast inhibits the antigen-induced release of inflammatory mediators (e.g., histamine, leukotriene C4, D4, E4) from human mast cells. Allergic reactions lead to cell-degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil. Once released, histamine can react with local or widespread tissues through histamine receptors. Histamine, acting on H₁-receptors, produces pruritis and vasodilatation (allowing blood fluids to enter the area to cause swelling). Pemirolast is a histamine H1 antagonist. It competes with histamine for the normal H₁-receptor sites on effector cells of blood vessels to provide effective, temporary relief of watery and itchy eyes.
• Affected Organisms: Humans and other mammals
• Biotransformation: Hepatic (Ophthalmic)
• Half Life: 4.5 hours (Ophthalmic)
• Elimination: Following topical administration, about 10-15% of the dose was excreted unchanged in the urine.
• References: Tinkelman DG, Berkowitz RB: A pilot study of pemirolast in patients with seasonal allergic rhinitis. Ann Allergy. 1991 Feb;66(2):162-5. [Pubmed]
• External Links: RxList; Drugs.com

REFERENCES

• Tinkelman DG, Berkowitz RB: A pilot study of pemirolast in patients with seasonal allergic rhinitis. Ann Allergy. 1991 Feb;66(2):162-5. Pubmed