COC1=C2CC(C)CC(OC)C(O)C(C)/C=C(\C)C(OC(N)=O)C(OC)/C=C\C=C(/C)C(=O)NC(=C(/C=N/C(C)(C)C)C1=O)C2=O
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?