All chemicals applied were not subjected
to further purification. Super DHB, 2,5-dihydroxybenzoic acid:2-hydroxy-5-methoxybenzoic
acid (9:1) (sDHB, >99.0%), 2′,4′,6′-trihydroxyacetophenone
monohydrate (THAP, >95.5%), and 5-chloro-2-mercaptobenzothiazole
(CMBZT,
>90.0%) were purchased from Sigma-Aldrich (MO, USA), 9-aminoacradine
(9AA, >98.0%) was purchased from TCI America (OR, USA), 3-hydroxypicolinic
acid (HPA, > 99.9%) was purchased from Chem-Impex International
(IL,
USA), and α-cyano-4-hydroxy-cinnamic acid (CHCA, >99.0%)
was
purchased from Fluka-Honeywell (NC, USA). Methanol and acetonitrile
(Optima LC/MS grade) were purchased from Fisher Scientific (NH, USA).
Peptide Calibration Standard II and MTP 384 Target plate Ground Steel
TF were purchased from Bruker (MA, USA). Lipid standards, 1,2-dioleoyl-sn-glycero-3-phospho-(1′-rac-glycerol)
(sodium salt) (PG 18:1 (Δ9-Cis)), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (PE (18:1/16:0)), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate (sodium salt) (PA (18:1/16:0)), and
1-oleoyl-2-hydroxy-sn-glycero-3-phospho-(1′-rac-glycerol) (LPG(18:1)), were purchased from Avanti Polar
Lipids (AL, USA). Quinolone standards, 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS) and 2-heptyl-4-quinolinoal 1-oxide (HQNO),
and lactone standard N-hexanoyl-l-homoserine
lactone (HSL) were purchased from Cayman Chemical Company (MI, USA).
Quinolone standard 2-heptyl-4-quinolone (HHQ), rhamnolipids, 95%(mono–rhamnolipid
dominant), and rhamnolipids, 95% (di–rhamnolipid dominant)
were purchased from Sigma-Aldrich (MO, USA). Luria–Bertani
(LB) broth (Miller) and LB agar (Miller) were purchased from Fisher
BioReagents (PA, USA).
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