Figure 4. (A) 1H NMR spectrum (256 transients) acquired with peak 9 (Figure 3) containing thapsigargicin (2). Shown is a difference spectrum
obtained by subtraction of a spectrum obtained by eluting an empty cartridge from the actual spectrum in order to eliminate solvent resonances
(both spectra were acquired without solvent peak suppression). (B) COSY spectrum acquired with peak 9 (containing 2); 8 transients, 512
increments, total acquisition time 1.5 h. (C) HSQC spectrum acquired with peak 11 containing thapsigargin (1); 4 transients, 512 increments,
total acquisition time 43 min. (D) NOESY spectrum acquired with peak 11 (1); 16 transients, 1024 increments, total acquisition time 12 h. (E)
Aliphatic region of an HMBC spectrum acquired with peak 11 (1); 24 transients, 512 increments, total acquisition time 4 h.