The two hydrolysable tannin-related isolates, ellagic acid
(8) [18] and gallic acid (10) [19]were identified by comparison
with literature data. The eight hydrolysable tannin isolates
comprised three ellagitannins and five gallotannins. The three
ellagitannins were identified as casuarinin (3) [20], corilagin
(7) [21] and chebulagic acid (9) [21,22] by comparison with
published data. In the same vein, three of the five gallotannin
isolates were identified by comparison with literature as
chebulic acid (4) [23], 5-O-galloylshikimic acid (5) [24]
and pentagalloyl glucose (6) [25,26]. The remaining two
gallotannins, whose comparative 1H (500 MHz) and 13C
(125 MHz) NMR data are as shown in Table 1, and herein
named chebumeinin A (1) and chebumeinin B (2), are new
isomeric ester analogues of chebulic acid (4). The structures of