Showing structure for C[Si](C)(C)OC1C(O)C(COP(=O)(O)OP(=O)(O)OCC2OC3NC4=C(NC3C(S[Si](C)(C)C)=C2S)C(=O)[NH]C(N)=N4)OC1N1C=NC2=C(N)N=CN=C21