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Lamellarin D
Lamellarins are a group of pyrrole alkaloids first isolated in 1985 from the marine mollusk ''Lamellaria'' in the waters of Palau. Over 70 lamellarins and similar compounds were subsequently isolated. Other similar compounds include ningalins, lukianols, polycitones, and storniamides. Biological activity These compounds have shown a wide variety of biological activity, including reversal of multidrug resistance, HIV-1 integrase inhibition, and antibiotic activity. Lamellarin D, for example, displays strong cytotoxic activity against tumor cell lines, and is a potent topoisomerase I inhibitor. Structure The lamellarins all contain a central pyrrole ring, substituted at the 3 and 4 positions by polyhydroxy- or methoxyphenyls. They are divided into two groups, depending on whether the pyrrole ring is fused or unfused. Synthesis The lamellarins have been synthesized by a number of groups, including Isibashi, Steglich, Ruchirawat, Banwell, Alvarez, Gupton, Boger, and Handy. Steglich ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrrole
Pyrrole is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4 H4 NH. It is a colorless volatile liquid that darkens readily upon exposure to air. Substituted derivatives are also called pyrroles, e.g., ''N''-methylpyrrole, C4H4NCH3. Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme. Pyrroles are components of more complex macrocycles, including the porphyrinogens and products derived therefrom, including porphyrins of heme, the chlorins, bacteriochlorins, and chlorophylls. Properties Pyrrole is a colorless volatile liquid that darkens readily upon exposure to air, and is usually purified by distillation immediately before use. Pyrrole has a nutty odor. Pyrrole is a 5-membered aromatic heterocycle, like furan and thiophene. Unlike furan and thiophene, it has a dipole in which the positive end lies on the side of the heteroatom, with a dipole moment of 1.58 D. In CDCl3, it has ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
