This invention concerns new biocidal compounds of formula (I) wherein R is H
or CH3. Of particular interest are two isomers that are named malayamycin
A and desmethylmalayamycin A. These isomers, which may be prepared by growing under
controlled conditions a previously unknown strain of micro-organism from the species
Streptomyces malaysiensis, are characterised by nmr and mass spectroscopic
data. They have biocidal activity, including anti-fungal, anti-viral and anti-cancer
activity, and are of special interest for use in agriculture, horticulture, animal
and human health.
##STR1##