4-oxo-27-TBDMS Withaferin A

4-oxo-27-TBDMS Withaferin A is a derivative of the steroidal lactone withaferin A (Cay-11352) that has anticancer activity. It is cytotoxic to A2780 ovarian cancer cells (IC50 = 17 µM) but not to carboplatin-resistant A2780 (A2780/CP70) cells (IC50 = >100 µM). It is selective for A2780 cells over non-cancerous ARPE19 cells (IC50 = 1,660 µM). 4-oxo-27-TBDMS Withaferin A induces DNA fragmentation in A2780 cells.Formal Name: (5beta,6beta,22R)-27-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-5,6-epoxy-22-hydroxy-1,4-dioxo-ergosta-2,24-dien-26-oic acid, delta-lactone. CAS Number: 1214886-31-3. Molecular Formula: C34H50O6Si. Formula Weight: 582.9. Purity: >98%. Formulation: (Request formulation change), A solution in ethanol. Solubility: DMF: 5mg/mL, DMSO: 5mg/mL, DMSO:PBS (pH 7.2) (1:1): 0.5mg/mL. lambdamax: 224 nm. SMILES: O=C(C=C1)[C@@]2(C)[C@@]([C@H]3C[C@]4([H])[C@]2([H])CC[C@@]5(C)[C@@]4([H])CC[C@]5([H])[C@H](C)[C@@]6([H])CC(C)=C(CO[Si](C)(C)C(C)(C)C)C(O6)=O)(O3)C1=O. InChi Code: InChI=1S/C34H50O6Si/c1-19-16-26(39-30(37)22(19)18-38-41(8,9)31(3,4)5)20(2)23-10-11-24-21-17-29-34(40-29)28(36)13-12-27(35)33(34,7)25(21)14-15-32(23,24)6/h12-13,20-21,23-26,29H,10-11,14-18H2,1-9H3/t20-,21-,23+,24-,25-,26+,29+,32+,33-,34+/m0/s1. InChi Key: RZWFBNOFUAHADD-VTYRCZOESA-N.