Chartreusin aglycone

The biosynthesis of chartreusin aglycone (74) in Streptomyces spp. has been investigated using trans-cinnamic acid, sodium diethyl malonate, and methionine as radioactive substrates. Preliminary results indicate that the complete carbon skeleton is derived by the acetate-polymalonate route. Since direct formation of (74) by cyclization of a p-polyketo-e ter intermediate is impossible, it has been suggested that a linear tetracyclic compound (73) could be involved as a biosynthetic intermediate (Scheme 14). 

A number of new antibiotics have been reported which have related polycyclic aromatic aglycones 0-or C- glycosically linked to sugars. An unidentified strain of actinomycete (J 907-21) has yielded elsa-mycin A (23) and B (24), which are relatives of chartreusin the... 

Methylstreptothricin D has been isolated from a Streptomyces strain (SNU 8810-111). A mutant strain of S. chartreusis has produced a complex of antibiotics, chrymutasins, which are analogues of chartreusins, with the same disaccharide or trisaccharide chains of fucose and/or digitalose, but with modified aglycons. ... 

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