Tetracyclic pyridoacridine alkaloids

The known tetracyclic pyridoacridine alkaloids from marine sources are dominated by those isolated from tunicates. All reported tetracyclic pyridoacridine alkaloids to date have oxygen functionality at C8, and the alkaloids can readily be divided into a group that has a carbonyl group at... 

Table 4. Reported Cytotoxicity of Some Tetracyclic Pyridoacridine Alkaloids...

Copp, B.R., Jompa, J., Tahir, A., and Ireland, C.M. (1998) Styelsamines A-D new tetracyclic pyridoacridine alkaloids from the Indonesian ascidian Eusynstyda latericius. J. Org. Chem., 63,8024-8026. 

Spanish workers have recently described a rapid method for the construction of pyridoacridines which could be of value for the synthesis of a range of cytotoxic pyridoacridine alkaloids. Thus, treatment of MEM-protected 4-quinolone 1 with 3 equivalents of LDA in THF, first at -78°C then with stirring at room temperature, followed by addition of 1 equivalent of methyl 3-formyl-2-pyridinecarboxylate gave, after quench with aqueous ammonium chloride and chromatography, a mixture of the tetracycles 2 (15%) and 3 (20%). Oxidation of either 2 or 3, or a mixture of 2... 

In 1988, Kobayashi et al. reported the isolation and structure elucidation of three tetracyclic pyridoacridine type alkaloids called cystodytin A (379),... 

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