Marine Natural Products and Immunoactive Substances, Basic Research of α-Galactosylceramides
Keywords:
Agelasphin, α-Galactosylceramide, α-GalCer, KRN7000, NKT cellAbstract
Marine organisms produce second metabolites with unique chemical structures because of their complex symbiotic systems different from that of land organisms. Unique glycosphingolipids with α-galactosylceramide structure, agelasphins, were obtained from the Okinawan marine sponge Agelas mauritianus by the in vivo antitumor substance screening system. Agelasphins and the developmental candidate, KRN7000 (α-GalCer), markedly showed antitumor activity against tumor-bearing mice by activating the host’s immune system. The discovery of agelasphins and the development of KRN7000 revealed the detail of natural killer T cell functions. Unfortunately, the development of KRN7000 intended to be an antitumor drug by systemic injection was abandoned because of several limitations. Now it is strongly expected that agelasphin or its derivative to be developed as a novel immunomodulator by conquering the limitations.
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