FIG. 2.

(A) CID mass spectrum of the compound found in the fraction eluting in 100% ACN. (B) Fragmentation scheme for the component with [M + H]⁺ at m/z 331. Boldface numbers indicate fragment masses of the ions obtained from the deuterated component. Small numbers refer to the atom numbering used to assign the NMR data summarized in Table 3. The H atoms shown in boldface correspond to exchangeable protons.