Natural products that resensitize MRSA 1556 to oxacillin. Michellamine B diacetic acid salt (E12, plate 13160330), cryptopimaric acid (F13, plate 13160330), CAS 32986-79-1 (G9, plate 13160330), sirodesmin A (I11, plate 13160331), and variabiline dihyrdrochloride (L16, plate 13160331) were all able to lower the MIC of oxacillin 16-fold in MRSA 1556. Natural products were tested at 20 μM.