Skeleton Reassignment of Type C Polycyclic Polyprenylated Acylphloroglucinols YangXing-Wei YangJing XuGang 2016 The previous assignment of the type C skeleton of polycyclic polyprenylated acylphloroglucinols (PPAPs) was controversial and proved to be incorrect in this study. The structures of the type C PPAPs (<b>3</b>–<b>6</b>) were revised to corresponding type A structures (<b>3a</b>–<b>6a</b>) via <sup>13</sup>C NMR spectroscopic analysis and a quantum computational chemistry method. Therefore, only types A and B PPAPs are likely present in plants of the family Clusiaceae.