Butyrolactones from the fungus Aspergillus terreus BCC 4651.

Two new butenolides, butyrolactones VI (1) and VII (2), were isolated together with six known compounds, butyrolactones I (3), II (4), IV (5), and V (6), aspernolide B (7), and bisdethiodi(methylthio)acetylaranotin (8) from the fungus Aspergillus terreus BCC 4651. Compound 8, exhibiting a minimum inhibitory concentration (MIC) value of 1.56 µg/ml against Mycobacterium tuberculosis H37Ra, proved to be the antimycobacterial principle from the culture of this fungus. On the other hand, butyrolactone V (6) showed antiplasmodial activity against Plasmodium falciparum K1 with an IC₅₀ of 7.9 µg/ml.