Antifungal microbial metabolites discovered by activity-based
screening
Microbial metabolites are promising antifungal antibiotics
as agricultural fungicides, which were discovered
through intensive activity-based screening.
Rice blast disease has been a major target in
screening for antifungal metabolites, as previously
demonstrated for blasticidin S and kasugamycin. Chaetoviridins
A and B have recently been purified from the
broth of Chaetomium globosum (Takahashi et al.,
1990). Chaetoviridin A (Fig. 3) exhibited a higher
level of in vitro and in vivo antifungal activity against
M. grisea than chaetoviridin B (Park et al., 2005).
Treatment with chaetoviridin A at 62.5 lg ⁄ ml suppressed
development of rice blast by over 80%, but
showed moderate control of tomato late blight at
125 lg ⁄ ml.