抄録
Natural products have their important meanings in biological systems. Isolation of new natural products and synthesis of small molecules based on their scaffolds would be of chemical relevance to living cells and organs. In this study, we focused on the Wnt signaling, which pathways show aberrant activation in many cancer cells. We synthesized natural products melleumin A (1) and B (2), and trans-dihydroarcyriarubin C, which were isolated by us from myxomycetes (true slime molds), and also synthesized their isomers. Melleumin A (1) and B (2) are novel peptide compounds isolated from the myxomycete Physarum melleum. Their syntheses have been achieved by coupling procedures of their components, L-threonine, glycine, and an unusual amino acid, a tyrosine-attached acetic acid. We found cis-dihydroarcyriarubin C (12), and isomers of melleumin B are moderate inhibitors of Wnt signal transcription. We also developed a high-throughput system for analyzing of inhibition of making a complex between TCF and β-catenin by using microplates. The regulation of transcription by TCF/β-catenin complex is a final step of the Wnt signal pathway. In this assay, cis-dihydroarcyriarubin C (12) showed inhibition, which indicates that a cell-based Wnt signal inhibition would be caused by disruption of TCF/β-catenin complex. We also found several natural products from our natural products library that show a cell-based Wnt signal inhibition and a protein-based TCF/β-catenin complex inhibition.
