- Four new colchicinoids, gloriosamines A-D, from Gloriosa rothschildiana
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Four new colchicinoids, gloriosamines A-D, were isolated from the aerial parts of Gloriosa rothschildiana. The structure of gloriosamine A, including the absolute configuration, was determined by chemical conversion from colchicine.
- Kitajima, Mariko,Tanaka, Akiko,Kogure, Noriyuki,Takayama, Hiromitsu
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- Synthesis of Two Aromatic Methylenedioxy-Substituted Colchicine Congeners: Elucidation of the Structure of Cornigerine as 2,3-(Methylenedioxy)-2,3-Didemethoxycolchicine
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Treatment of colchicine with concentrated sulfuric acid at 80-90 deg C afforded besides 2-demethylcolchicine a mixture of catecholic colchicines which could be separated and identified.Similar treatment of 1-demethyl- and 3-demethylcolchicine gave predominantly the 1,2-catechol or its 2,3 isomer.Methylenation of these catechols afforded the colchicine congeners 1 and 10.A comparison with natural cornigerine revealed that the alkaloid was identical with the 2,3-methylenedioxy compound 10 and not with 1, as formerly proposed.
- Roesner, Manfred,Hsu, Fu-Lian,Brossi, Arnold
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- PHENOLIC CONGENERS OF COLCHICINE: PREPARATION AND CHARACTERIZATION OF PHENOLIC AND CATECHOLIC ANALOGUES OF COLCHICINE, COLCHICEINE AND THIOCOLCHICINE
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Treatment of 2-demethylcolchicine (2) with sulfuric acid afforded 1,2-didemethylcolchicine (6) as the major, and 2,3-didemethylcolchicine (8) as the minor product. 2,3-Didemethylcolchicine (8) was prepared from 3-ethoxycarbonyl-3-demethylcolchicine by sulfuric acid treatment.Hydrolysis of catecholic compounds 6 and 8 with 0.1 N hydrochloric acid afforded colchiceines 13 and 14, respectively.Ester derivatives of 2-demethyl- and 3-demethylcolchicine, and of catechols 6 and 8 were prepared.A direct conversion of 3 into 3-demethylthiocolchicine (15) and conversion of 15 into ester derivatives is described.Cleavage of the ether groups of colchicine by boron tribromide is also reported.
- Muzaffar, Anjum,Chrzanowska, Maria,Brossi, Arnold
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p. 365 - 372
(2007/10/02)
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