Fig 4. Fragmentation and identification of adenosine-containing lipids revealed terpene nucleoside family members.

(A) Annotated fragments and calculated masses of lipid-linked 1-TbAd derivatives detected by CID-MS. The R group was assigned as ribose-linked based on ribose-fatty acyl fragments with the 2-linkage favored based on its chemical reactivity and known structures; however, linkage position could not be assigned directly from MS. (B) CID-MS showed diverse fragmentation patterns containing adenosine and consistent with parent terpene nucleosides containing lipid-conjugated ribose. Observed masses are shown. (C) Schematic shows the unsupervised lipidomic discovery process for the new TbAd-like lipids. (D) Thirteen lipids were identified as Rv3378c dependent and validated through CID-MS and synthetic chemistry.