carbons, those assigned to the DHDG (δC 163.1 and 164.1) and the isoDHDG (δC 165.1 and 166.7) groups showed broad signals, which were attributed to the macrocyclic structure, because analogous features were also seen in those of the related hirtellins C(11) and F (12).9 The 1H-1H COSY data for 10 (Table 1) showed upfield shifts in the glucose-1 H-4 (δH 3.87) and H-6 (δH 3.85 and 3.75), implying the presence of free OH-4 and OH-6 on the glucose-1 pyranose ring. The appearance of the remaining proton signals at lower field (Table 1) indicated complete acylation of the remaining hydroxy groups on the glucopyranose rings. The locations of two galloyl groups were assigned to O-3 of each glucose core on the basis of the HMBC correlations between the galloyl signal at δH 7.05 and the glucose-1 H-3 signal (δH 5.60) via a common carbonyl carbon signal (δC 167.0) and those between the galloyl signal at δH 6.97 and the glucose-2 H-3 signal (δH 5.70) via a common carbonyl carbon signal (δC 166.8). Consequently, each of the DHDG and the isoDHDG groups in 10 were assigned to bridge between the O-1 of one glucose core and the O-2 of the other in a mode corresponding to the formation of a macrocyclic structure. HMBC correlations concerning the broad glucose proton signals due to the glucose-1 H-1, and the glucose-2 H-1 and H-2, with the isoDHDG group protons were not observed. However, the spectrum showed an HMBC correlation between the DHDG H-6′ (δH 7.11) signal and the glucose-1 H-2 signal (δH 5.32) via a carbonyl carbon peak (δC 163.0, DHDG C-7′), indicating that the galloyl part bearing one DHDG unit hydrogen (ring-D2) was attached to the glucose-1 O-2. The remaining carbonyl carbon signal (δC 164.1) was assigned to DHDG C-7 on the basis of the two- bond HMBC correlation with the DHDG group H-2 (δH 6.44) and