Density Functional Theory Calculation of 13C NMR Shifts of Diazaphenanthrene Alkaloids: Reinvestigation of the Structure of Samoquasine A

The C-13 NMR shifts of 48 diazaphenanthrene-type alkaloids have been calculated at the B3LYP/6-311+G(2d,p) level of theory. The results support the structural reassignment of samoquasine A as 2.