File S1 - Cyclic Lipodepsipeptides Produced by Pseudomonas spp. Naturally Present in Raw Milk Induce Inhibitory Effects on Microbiological Inhibitor Assays for Antibiotic Residue Screening

File includes Figures S1–S12 and Tables S1–S4. Figure S1: LC-MS chromatogram of the acidified mixture prior to purification using UV-detection at 214 nm. The isolated fractions are indicated with braces and the individual peptides with arrows. Figure S2: Mass spectra of isolated lipopeptides 1–4 obtained during LC-MS analysis of the extracted mixture prior to purification. The range of detectable m/z values was limited to 1500 Da, ESI (Positive mode). Figure S3: 1D 1H spectrum of peptide 4 in DMF-d7 solution, 25°C, 700 MHz. Figure S4: 2D 1H-1H TOCSY spectrum of peptide 4 in acetone-d6 solution, 25°C, 500 MHz, revealing the characteristic amino acid spin system patterns. Figure S5: Established 1H-1H ROE contacts in peptide 4, observed in a 2D 1H-1H ROESY spectrum with 300 ms mixing time in DMF-d7 solution. Figure S6: 3JCH contacts between Thr3 Hβ and carbonyl carbons of peptide 4, observed in a 2D 1H–13C HMBC experiment, 25°C, 700 MHz, in DMF-d7 solution. Figure S7: High resolution mass spectrum of peptide 4. Figure S8: 1D 1H spectrum of peptide 1 in DMF-d7 solution, 25°C, 700 MHz. A) HN region, B) Hα region and C) aliphatic region spectrum. Figure S9: High resolution mass spectrum of peptide 1. Figure S10: High resolution mass spectrum of peptides 2/3. Figure S11: A diagram plotting the 1H and 13C chemical shifts of the CHα units of massetolide A (blue) from Gerard et al, J. Nat. Prod. (1997) 60:223–229, and peptide 1 (red) in acetone-d6 solution recorded at 500 MHz, 25°C. The arrow indicates the remarkable difference in chemical shift of the 5th residue, suggesting a difference in configuration. Figure S12: Overlay of 2D 1H-13C HSQC spectra of peptide 1 (blue) and WLIP (red) in DMF-d7 solution, recorded at 500 MHz, 25°C, CHα-region. The similarity for the chemical shift of the Leu5 residue suggests the milk peptides 1–4 belong to the D-subgroup of CLPs. Table S1: 1H and 13C NMR assignment of peptide 4 in DMF-d7 solution, 25°C, 700 MHz. Table S2: 1H and 13C NMR assignment of peptide 1 in DMF-d7 solution, 25°C, 700 MHz. Table S3: 1H and 13C NMR assignment of peptide 1 in acetone-d6 solution, 25°C, 500 MHz. Table S4: 1H and 13C NMR assignment of peptide 4 in acetone-d6 solution, 25°C, 500 MHz. (DOCX)