Skip to main content

Advertisement

Table 2 Summary of the antimicrobial compounds in the three main absorbing fractions that were identified using UPLC-MS and UPLC-MSe. PAX peptide identities and names are from Fuchs et al. [32]

From: Xenorhabdus khoisanae SB10 produces Lys-rich PAX lipopeptides and a Xenocoumacin in its antimicrobial complex

Fraction UPLC Rt (min) m/z of major [M + H]+ Compound Mra Theoretical Mrb Mass error (ppm)c Proposed compound identity
B 4.27 407.2182 406.2104 406.2104 0.0 Xenocoumacin 2 (C21H30N2O6)
2.93 1052.7948 1051.7870 1051.7845 2.4 PAX1’ (C14H27O2)GK6
C 3.18 1078.8119 1077.8041 1077.8001 3.7 PAX7E1* (C16H29O2)GK6
3.42 1070.8091 1069.7921 1069.7951 −2.8 PAX1L* (C14H29O3)GK6
D 3.29 1066.8097 1065.7965 1065.8001 −3.4 PAX3’ (C15H29O2)GK6
F 3.47 1054.8115 1053.8012 1053.8001 1.0 PAX1L-DH* (C14H29O2)GK6
3.32, 3.47# 1080.8286 1079.8191 1079.8158 3.1 PAX7 (C16H31O2)GK6
3.71 1078.8096 1077.8002 1077.8001 0.1 PAX7E2* (C16H29O2)GK6
3.88 1078.8070 1077.7979 1077.8001 −2.0 PAX7E3* (C16H29O2)GK6
G 2.51 1050.7723 1049.7623 1049.7688 −6.2 PAX5 (C14H25O2)GK6
  2.90 1052.7936 1051.7821 1051.7845 2.3 PAX1’ (C14H27O2)GK6
  3.57 1080.8280 1079.8161 1079.8158 0.3 PAX7 (C16H31O2)GK6
  3.83 1106.8412 1105.8294 1105.8314 −1.8 PAX8 (C18H33O2)GK6
  1. aExperimental monoisotopic Mr of compound was calculated using the TOF transform or MaxEnt3 function in the MassLynx 4.01 software package
  2. bTheoretical monoisotopic Mr of compound was calculated from accurate monoisotopic Mr of Lys =128.09496 and Gly = 57.02146, and monoisotopic Ar of O =15.9949146; H=1.0078250, N=14.0030740 and C=12.0000000
  3. cMass error in parts per million (ppm) = 106×{Mr (theoretical) - Mr (experimental)}/ Mr (theoretical)
  4. #Early elution of broad peak, fronting and tailing due to aggregation at high concentration
  5. *Putative identification as PAX peptides from peptide moiety fragments and accurate mass determination, E denotes an enoyl group, L denotes linear, DH denotes dehydroxylated, structure of R-group was not elucidated
  6. Refer to Additional file 1 for UPLC-MS, ESMS and MS/MS data on all the compounds