In the course of screening for new anticancer antibiotics from myxobacteria, strain JW357 wasfound to produce an antibiotic that was active against several human cancer cell lines. This strainwas identified as Angiococcus disciformis by morphological and cultural characteristics. The antibioticproduced was identified as myxochelin A. It demonstrated significant cytotoxicity against certainhuman cancer cells with IC50 values ranging 1.15 to 2.36mg/ml. Myxochelin A was interestinglyas active against multidrug-resistant CL02 cells as against the sensitive parental cells (HCT15).