valspodar valspodar valspodar (psc833) is an experimental cancer treatment and chemosensitizer. it is a derivative of ciclosporin d (cyclosporin d). valspodar names iupac name (3s,6s,9s,12r,15s,18s,21s,24s,30s,33s)-6,9,18,24-tetraisobutyl-3,21,30-triisopropyl-1,4,7,10,12,15,19,25,28-nonamethyl-33--1,4,7,10,13,16,19,22,25,28,31-undecaazacyclotritriacontane-2,5,8,11,14,17,20,23,26,29,32-undecone other names psc833; psc-833 identifiers cas number 121584-18-7 y 3d model (jsmol) interactive image chemspider 4445174 pubchem cid 5281884 unii q7zp55kf3x y comptox dashboard (epa) dtxsid90873386 inchi inchi=1s/c63h111n11o12/c1-26-27-28-41(16)53(76)52-57(80)67-49(38(10)11)61(84)68(19)33-48(75)69(20)44(29-34(2)3)56(79)66-50(39(12)13)62(85)70(21)45(30-35(4)5)55(78)64-42(17)54(77)65-43(18)58(81)71(22)46(31-36(6)7)59(82)72(23)47(32-37(8)9)60(83)73(24)51(40(14)15)63(86)74(52)25/h26-27,34-47,49-52h,28-33h2,1-25h3,(h,64,78)(h,65,77)(h,66,79)(h,67,80)/b27-26+/t41-,42+,43-,44+,45+,46+,47+,49+,50+,51+,52+/m1/s1key: yjdydfnkcbantm-qcwcskbgsa-ninchi=1/c63h111n11o12/c1-26-27-28-41(16)53(76)52-57(80)67-49(38(10)11)61(84)68(19)33-48(75)69(20)44(29-34(2)3)56(79)66-50(39(12)13)62(85)70(21)45(30-35(4)5)55(78)64-42(17)54(77)65-43(18)58(81)71(22)46(31-36(6)7)59(82)72(23)47(32-37(8)9)60(83)73(24)51(40(14)15)63(86)74(52)25/h26-27,34-47,49-52h,28-33h2,1-25h3,(h,64,78)(h,65,77)(h,66,79)(h,67,80)/b27-26+/t41-,42+,43-,44+,45+,46+,47+,49+,50+,51+,52+/m1/s1key: yjdydfnkcbantm-qcwcskbgbb smiles c/c=c/c(c)c(=o)1c(=o)n(c(=o)n(cc(=o)n((c(=o)n(c(=o)n((c(=o)n(c(=o)n(c(=o)n((c(=o)n((c(=o)n((c(=o)n1c)c(c)c)c)cc(c)c)c)cc(c)c)c)c)c)cc(c)c)c)c(c)c)cc(c)c)c)c)c(c)c properties chemical formula c63h111n11o12 molar mass 1214.646 g·mol−1 except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). infobox references its primary use is as an inhibitor of the efflux transporter p-glycoprotein. previous studies in animal models have found it to be effective at preventing cancer cell resistance to chemotherapeutics, but these findings did not translate to clinical success. adverse effects valspodar can cause nerve damage.