The cell-free supernatant of the 7.0 L shake culture was
extracted by dichloromethane. The yellow organic phase was concentrated
to dryness. The TLC plate analysis showed the presence
of an active yellow spot designated A, detected by bioautography
at Rf = 0.37, which exhibited antibacterial and antifungal activities.
The preparative silica gel plates were then used to spot
dichloromethane crude extract in bands in order to collect an
appreciable quantity. The active bands were recovered and desorbed
in methanol, concentrated to dryness and used for the final
purification by HPLC using a reverse-phase column