TunR2 is an antibiotic and derivative of tunicamycin .1It is active againstB. subtilis(MIC = 0.3 μg ml) and increases the efficacy of the β-lactam antibiotics oxacillin , methicillin , and penicillin G againstB. subtiliswhen used at a concentration of 0.4 μg ml. Unlike tunicamycin, TunR2 is non-toxic toS. cerevisiae(MIC = >10 μg ml) and does not inhibit glycosylation in a protein N-glycosylation assay. TunR2 also has reduced antiproliferative activity against MDA-MB-231 and CHO cells compared with tunicamycin. 1.Price, N.P., Hartman, T.M., Li, J., et al.Modified tunicamycins with reduced eukaryotic toxicity that enhance the antibacterial activity of β-lactamsJ. Antibiot. (Tokyo)70(11)1070-1077(2017)