Fig 3.

MS/MS profiles of 430 lipid species. Samples of the highly enriched preparation of lipid 654 were subjected to either KOH or NaOCH₃ treatment as described in Materials and Methods. The highly enriched lipid 430 (Fig. 1, fraction 39) prepared from the total lipids of P. gingivalis was compared with the KOH- or NaOCH₃-hydrolyzed lipid 654 samples by using MS/MS analysis as described in Materials and Methods. The partial mass spectra are depicted for the m/z 430 lipid species recovered from HPLC-fractionated total lipids of P. gingivalis (A), NaOCH₃-treated lipid 654 (B), or KOH-treated lipid 654 (C). The proposed structure shown in panel D represents the deesterified form of the 654 lipid species shown in Fig. 2G. See the Fig. 2 legend for reconciliation of the low-mass product ions (<200 amu).