Chaetoglobins A And B, Two Unusual Alkaloids From Endophytic Chaetomium Globosum Culture

摘要

Chaetoglobins A (1) and B (2), two azaphilone alkaloid dimers with an unprecedented skeleton, were characterized from an endophytic fungus Chaetomium globosum with the former ascertained to be a significant cytotoxin valuable for anti-tumor drug discovery.rnThe field-growing plants harbor a wide range of symbiotic microorganisms named collectively "endophyte", which are actually fungi and bacteria living inter- and intra-cellularly in the apparently healthy plant tissues. The existence of endophytes helps the hosts' overall adaptability to an array of stresses such as salinity, drought, heat, predators' attack and pathogens' colonizations, in return to the nutrition and protection the plants provide. Endophyte has been assumed to be genetically unique owing to the high tendency that it might have acquired the host derived genes such as transposons. That is why endophytic microbes are being accepted as a fresh and rich source of functional biomolecules. In our proceeding paper, we described the characterization of a series of bioactive macrocyclic indole alkaloids from the EtOAc extract of the solid substrate culture of C. globosum IFB-E019, an endophytic fungus residing inside the normal stem of Imperata cylindrical.