This invention relates to a new class of polyene polyketides, their
pharmaceutically acceptable salts and derivatives, and to methods for
obtaining the compounds. One method of obtaining these compounds is by
cultivation of novel strains of Streptomyces aizunensis; another method
involves expression of biosynthetic pathway genes in transformed host
cells. The present invention further relates to the novel strains of
Streptomyces aizunensis used to produce these compounds, to the use of
these compounds and their pharmaceutically acceptable salts and
derivatives as pharmaceuticals, in particular to their use as inhibitors
of fungal cell growth and cancer cell growth. The invention also relates
to pharmaceutical compositions comprising these novel polyketides or a
pharmaceutically acceptable salts or derivatives thereof. Finally, the
invention relates to novel polynucleotide sequences and their encoded
proteins, which are involved in the biosynthesis of these novel
polyketides.