台灣本土真菌 Neosartorya fischeri 之二次代謝物之化學結構及生物活性分析

Abstract

Ever since antibiotics were discovered and introduced into modern medicine, they have played a pivotal role in the improvement of public health. However, unlike other frequently prescribed drugs, antibiotics tend to gradually lose their efficacy due to the evolution of drug-resistant bacteria. The emergence of multi-drug resistance has become one of the major threats to global healthcare; therefore, finding novel antibiotics has become a critical key to fight against bacterial infections. Since natural products are rich in structural diversity and are evolutionarily produced to be drug alike, they remain important sources of potential drug leads. Here, several secondary metabolites were isolated from an indigenous fungal species, Neosartorya fischeri, collected from soil in Hualien, Taiwan. The fungus was cultured, then its secondary metabolites were extracted and purified with chromatographic techniques (Size-exclusion and silica gel OPC, HPLC) to obtain pure compounds. All chemical structures were elucidated using spectroscopic methods (NMR, FTIR, HR-ESI-MS). Moreover, bioassays were conducted to evaluate their bioactivities. Two diterpenoids sartorypyrone A and aszonapyrone A, one indole alkaloid acetylaszonalenin, and two novel N-formyl alkaloids were reported in this study. Among the compounds being identified thus far, compound 1, sartorypyrone A, showed the best antimicrobial activities against Gram-positive bacteria and even against Methicillin-resistant Staphylococcus aureus (MRSA). In addition, it also showed anticancer activity. Therefore, we believe it can be a potential lead compound for drug development.