Fig. 2. UBI-2 is unstable at 37 °C. HPLC chromatograms (gradient acetonitrile + 0.1% formic acid/water + 0.1% formic acid from 5/95 to 95/5 over 10 min, then isocratic for 4 min; detection at 380 nm). UBI-2 (1 mg mL^–1 in PBS, upper panels) and UBI-3 (1 mg mL^–1 in PBS, lower panels) at (A) day 0 and (B) day 3 after incubation at 37 °C.