| Budget Amount *help |
¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2006: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2005: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2004: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2003: ¥800,000 (Direct Cost: ¥800,000)
|
|---|
| Research Abstract |
Madangamine A is a pentacyclic alkaloids that was isolated from the marine sponge Xestospongia ingens by Andersen in 1994. Soon after, new constituents of this alkaloid type, madangamines B-E, were isolated from the same organism. Madangamine A exhibits cytotoxic activities against P388, A549, U373, and MCF-7 tumor cell lines. In this research project, I have accomplished the construction of the ABC and ACE-ring frameworks of madangamines. N, O-Acetalization of the keto-aminophenol allows rapid construction of the 2-azabicyclo[3.3.1]nonane skeleton with a quaternary carbon center at C4. This strategy enabled the stereoselective construction of the central diazatricyclic core (ABC-ring) of the madangamine alkaloids. In the next stage of our investigation, an efficient construction of the madangamine tricyclic ring, 4-azatricyclo[11.2.2.0^<4.14>]heptadec-12-ene, including an 11-membered macrocycle (ACE-ring) has been accomplished via construction of the 2-azabicyclo[3.3.1]nonane skeleton by N, O-acetalization of a cyclohexanone derivative, geometry-retained cross-coupling reaction, and intramolecular reductive amination. From the results obtained above, my future studies will be focused on the construction of a 15-membered macrocycle (D-ring) for the total synthesis of madangamines.
|
