The H and 13C NMR data of 1(Tables 1 and 2) were found to be very similar to those of grandidentatin (13)
12 with major differences in the downfield shift of C-1 and C-2 (δC85.1 and 74.0 for1;δC80.0 and 71.5 for13, respectively), indicating 1to be a stereoisomer of 13. The planar structure of 1 was elucidated through 2D NMR analysis (
1H−1 H COSY, HMQC, and HMBC; see Figure 1). Alkaline hydrolysis of 1afforded trans-p-coumaric acid and (1R,2R)-trans-1,2-cyclohexanediol-1-O-β-D-glucopyranoside (1a), with the latter compound identified by comparing the optical rotation, HRFABMS, and 13C NMR data with previously reported values.