13C n.m.r. spin–lattice relaxation time measurements determining the major tautomer of 1-methylisoguanosine in solution
Abstract
Analysis of the contributions of 13C–1H dipolar interactions to the 13C n.m.r. spin-lattice relaxation times of the quaternary carbons of 1-methylisoguanosine establishes that the predominant tautomer in solution is the 2-keto, 6-amino form.