UK-1 is an antibiotic and antifungal inhibitor of topoisomerase II.
UK-1 is an unusual bis-benzoxazole metabolite isolated from a species of Streptomyces. UK-1 exhibits good antitumour activity but is devoid of antimicrobial activity. UK-1 acts as a magnesium ion-dependent, DNA binding agent and inhibitor of human topoisomerase II.
uk 1, an unusual bis-benzoxazole metabolite isolated from streptomyces sp. 517-02, is an inhibitor of topoisomerase ii (topo ii) and hepatitis c viral replication. it is an antifungal and an antibiotic, and displays a wide spectrum of potent anticancer activities against lymphoma, leukemia, and certain solid tumor-derived cell lines with ic50 values as low as 20 nm. however, uk 1 is devoid of antimicrobial activity and is inactive against pseudomonas aeruginosa and staphylococcus aureus, a methicillin-resistant strain of s. aureus. additionally, uk-1 can bind a wide variety of di- and tri-valent metal ions, particularly mg2+ ions, and form complexes with dna in the presence of mg2+ ions. topo ii are atp-dependent enzymes, which can simultaneously cut both strands of the dna helix to manage dna supercoils and tangles.
uk 1 strongly blocked the growth of human epitheloid carcinoma hela, mouse melanoma b16, mouse leukemia p388 cells with ed50 values of 1.22 μg/ml, 1.17 μg/ml, and 0.11 μg/ml, respectively. uk 1 did not display any growth inhibitory activity against bacteria, fungi and yeasts up to 100 μg/ml [1].
[1]. ueki, m., ueno, k., miyadoh, s., abe, k., shibata, k., taniguchi, m., & oi, s. uk-1, a novel cytotoxic metabolite from streptomyces sp. 517-02. i. taxonomy, fermentation, isolation, physico-chemical and biological properties. the journal of antibiotics. 1993; 46(7): 1089-1094.
