(R)-1,2,3,9-Tetrahydropyrrolo(2,1-b)quinazolin-3-ol

개요This quinazoline alkaloid was first isolated from the leaves of Adhatoda vasica Nees by Hooper and subsequently discovered in Peganum harmala under the name Peganine. The base is optically inactive although Spath and Kesztler have reported the isolation of the (-)-form from the fresh leaves of A. vasica and Rosenfeld and Kolesnikow have obtained the same form from the flowers and stems of Peganum harmala. The salts are readily obtained crystalline, e.g. the hydrochloride dihydrate, m.p. 208°C (dry); hydriodide dihydrate, m.p. 195°C (dry); picrate, m.p. 199°C (dec.) and the methiodide, m.p. 187°C.With AcOH, the alkaloid gives an anomalous acetyl derivative, m.p. 165°C, subsequently shown to be N-acetylpedadiene. Oxidation with KMn04 gives 4-quinazolone and 4-keto-3 :4-dihydroxyquinazolyl-3-acetic acid, the latter characterized as the methyl ester, m.p. 152°C.The crude drug from A. vasica is used in India as a remedy for asthma while the pure alkaloid acts as a bronchodilator.