Compound 12 shared the molecular formula C45H36O18 with 11 based on the (+)-HRESIMS peak at 865.1972 [M + H] + and the C NMR carbon counts. Comparison of the NMR data (Tables and) revealed that 12 is structurally closely related with 11, with the major differences were observed in resonances within unit III. Additionally, close similarities in the ECD curves of 12, especially the positive CE in diagnostic 220-240 nm region (Figure ), as compared to the ECD of 11, suggested that the only differences between 12 and 11 were the configurations of C-2 and C-3 in unit III. A cis-configuration of III-H-2 and III-H-3 could be gleaned from the unresolved thus small J2,3 value. Accordingly, units II and III had to be linked like in PACs 4 or 6. Owing to the spatial distance between the upper unit I and the terminal unit III, the chemical shift impact of unit I on unit III had to be small, especially in the C domain due to the shielding of the molecular hydrogen "envelope". Differential carbon chemical shift (C) could, thus, be used to determine the absolute configuration of unit III: units II and III were determined to be doubly connected as in 6 based on the close similarity of the C NMR data of the terminal unit III to that of the corresponding carbons in 6 (Table ). Thereby, the structure of 12 including its absolute configuration was elucidated as epicatechin-(4→8)-[PAC 6]. Although this structure had been reported earlier, the insufficiency of available NMR data and prior assignment puts its validity into question. Chiral phase HPLC and MS analysis of the phloroglucinolysis products of 12 further confirmed the compound to be assembled from dimer 6 and epicatechin (Figure ). The structure of 13 was established as that of cinnamtannin D1 by comparison of its C NMR data (Tables and), as well as it ECD spectrum (Figure ) with reported data. Phloroglucinolysis dissociated 13 into two major compounds, 3 and catechin, the structures of which were verified by chiral phase HPLC and MS (Figure ), collectively confirming 13 as