Figure 3.

Panel (A): High-resolution (Orbitrap) HPLC-ESI-MS profile of the acidic soluble fraction of whole saliva from preterm newborns (233 days of post-conceptional age (PCA)). The elution range (18–20 min) where Tβ₄ and Tβ₁₀ elute is evidenced by the colored box. Panel (B): XIC (eXtracted Ion Current) peaks were revealed by selecting four multicharged ions from [M + 8H⁺]⁸⁺ to [M + 5H⁺]⁵⁺ of Tβ₄ (upper lane) and Tβ₁₀ (bottom lane). The ESI spectrum and the corresponding deconvolution of Tβ₄ are shown in Panels (C,D), respectively. The ESI spectrum and the corresponding deconvolution of Tβ₁₀ are shown in Panels (E,F), respectively. Deconvolutions allowed us to determine the experimental M (monoisotopic) of Tβ₄ (Panel (D), theor. 4960.486) and Tβ₁₀ (Panel (F), theor. 4933.523).