B. Kunze et al., Apicularens A and B, new cytostatic macrolides from Chondromyces species (Myxobacteria): Production, physico-chemical and biological properties, J ANTIBIOT, 51(12), 1998, pp. 1075-1080
A never macrolide, apicularen A, was produced by several species of the gen
us Chondromyces. Initially it was discovered by bioassay-guided RP-HPLC-fra
ctionation of culture extracts of Chondromyces robustus, strain Cm a13. Api
cularen A showed no antimicrobial activity, but was highly cytotoxic for cu
ltivated human and animal cells, with IC50 values ranging between 0.1 and 3
ng/ml. A cometabolite of apicularen A, the N-acetylglucosamine glycoside a
picularen B, was distinctly less cytotoxic with IC50 values between 0.2 and
1.2 mu g/ml, and showed weak activity against a few Gram-positive bacteria
. Apicularen A is chemically closely related to the salicylihalamides A and
B from the marine sponge Haliclona sp.