Polyalthia acuminata Thw. (Annonaceae) has furnished the new aporphines (-)-norliridinine (1), (-)-3-hydroxynornuciferine (2), (-)-norannuradhapurine (9), and (-)-noroliveroline (11). Monophenolic aporphines bearing the phenol group at C-3 exhibit both a bathochromic shift as well as hyperchromic effect in their uv spectra in basic solution. N-Methylation of 1 yields (-)-liridinine, which is thus firmly represented by expression 7. Similar treatment of 2 leads to (-)-3-hydroxynuciferine (8) which is identical with the alkaloid (-)-hinine, establishing the position of the phenol in (-)-liridinine. The location of the phenolic group in 1 and 2 was established by comparison of their uv spectra. The third new alkaloid (-)-norannuradhapurine (9) was found to possess the R configuration via circular dichroism (cd) and its phenol position at C-8 was indicated by uv spectral data. The fourth new aporphine (-)-noroliveroline (11) has the R configuration as shown by cd. With the establishment of phenolic positions in 1 and 2, and clarification of structures of (-)-liridinine (7) and (-)-hinine (8), it becomes possible to locate with certainty the position of a phenolic group on ring A of an aporphine using nmr and uv spectra (neutral and basic). Examples include the structures of xyloguyelline and O-demethylpurpureine.