Compound characterization data — Gwenaëlle Jézéquel et al., 2026

Gwenaëlle Jézéquel, Dominik Kolling, Roya Shafiei, Katharina Rox, Andreas M. Kany, Norbert Sträter, Jesko Koehnke, Jörg Haupenthal, Anna K. H. Hirsch. “Stable phosphonate inhibitors of elastase LasB suppress Pseudomonas aeruginosa virulence via zinc-targeting pyrrolidone scaffolds.” ChemRxiv (2026). https://doi.org/10.26434/chemrxiv.15007028/v2

3-bromo-1-(3,4-dichlorophenyl)pyrrolidin-2-one
Identifier	5a
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, DMSO)	δ 8.05 (d, J = 2.3 Hz, 1H), 7.75 – 7.63 (m, 2H), 4.95 – 4.87 (m, 1H), 3.97 (dt, J = 10.0, 7.0 Hz, 1H), 3.90 (ddd, J = 9.9, 7.7, 3.6 Hz, 1H), 2.77 (dq, J = 14.6, 7.3 Hz, 1H), 2.34 (ddt, J = 14.3, 7.2, 3.7 Hz, 1H)
¹³C NMR (126 MHz, DMSO)	δ 170.3, 139.3, 131.7, 131.0, 127.0, 121.4, 120.1, 47.2, 46.7, 29.5
MS (ESI⁺) m/z	306.92 [M+H]⁺

3-bromo-1-phenylpyrrolidin-2-one
Identifier	5b
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, CDCl₃)	δ 7.62 – 7.53 (m, 2H), 7.38 – 7.27 (m, 2H), 7.13 (ddt, J = 8.6, 7.3, 1.2 Hz, 1H), 4.55 – 4.46 (m, 1H), 4.04 – 3.93 (m, 1H), 3.83 – 3.73 (m, 1H), 2.73 – 2.59 (m, 1H), 2.39 (ddt, J = 14.3, 6.5, 2.7 Hz, 1H)
¹³C NMR (126 MHz, CDCl₃)	δ 169.5, 138.9, 129.0 (2C), 125.4, 120.1 (2C), 46.7, 45.4, 30.0
MS (ESI⁺) m/z	240.00 [M+H]⁺

diethyl (1-(4,5-dichlorophenyl)-2-oxopyrrolidin-3-yl)phosphonate
Identifier	6a
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, MeOD)	δ 7.87 (d, J = 1.9 Hz, 1H), 7.42 (d, J = 2.0 Hz, 2H), 4.21 – 4.04 (m, 4H), 3.94 – 3.75 (m, 3H), 2.53 – 2.24 (m, 2H), 1.25 (t, J = 7.0 Hz, 6H)
MS (ESI⁺) m/z	366.04 [M+H]⁺

diethyl (1-phenyl-2-oxopyrrolidin-3-yl)phosphonate
Identifier	6b
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, DMSO)	δ 7.66 – 7.60 (m, 2H), 7.45 – 7.35 (m, 2H), 7.17 (td, J = 7.4, 1.2 Hz, 1H), 4.19 – 3.93 (m, 5H), 3.92 – 3.80 (m, 2H), 3.43 (ddd, J = 21.6, 10.0, 6.1 Hz, 1H), 2.50 – 2.19 (m, 1H), 1.25 (td, J = 7.2, 4.0 Hz, 6H)
¹³C NMR (126 MHz, DMSO)	δ 169.0, 139.7, 129.2 (2C), 124.9, 120.2 (2C), 62.7, 62.2, 47.4, 42.7, 20.2, 20.2, 16.8, 16.7
MS (ESI⁺) m/z	298.12 [M+H]⁺

(1-(4,5-dichlorophenyl)-2-oxopyrrolidin-3-yl)phosphonic acid
Identifier	7a
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, MeOD)	δ 8.02 (d, J = 2.3 Hz, 1H), 7.58 – 7.49 (m, 2H), 3.98 (q, J = 8.1 Hz, 1H), 3.90 (td, J = 8.9, 4.7 Hz, 1H), 3.19 (ddd, J = 22.0, 10.0, 5.9 Hz, 1H), 2.48 (qt, J = 13.0, 9.0 Hz, 2H)
¹³C NMR (126 MHz, MeOD)	δ 170.7, 139.0, 132.0, 130.1, 127.4, 121.8, 119.4, 43.9, 42.8, 19.9
HRMS (ESI⁺)	calcd for C₁₀H₁₁Cl₂NO₄P⁺ [M+H]⁺ 309.9797, found 307.9795

(1-phenyl-2-oxopyrrolidin-3-yl)phosphonic acid
Identifier	7b
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, MeOD)	δ 7.65 – 7.58 (m, 2H), 7.57 (s, 2H), 7.43 – 7.36 (m, 2H), 7.25 – 7.17 (m, 1H), 4.01 (td, J = 8.7, 6.8 Hz, 1H), 3.92 (td, J = 8.9, 4.9 Hz, 1H), 3.17 (ddd, J = 21.9, 9.8, 5.8 Hz, 1H), 2.50 (dddd, J = 32.0, 21.3, 11.2, 7.2 Hz, 2H)
¹³C NMR (126 MHz, MeOD)	δ 170.6, 139.1, 128.4 (2C), 124.9, 120.8 (2C), 43.9, 42.8, 20.1
HRMS (ESI⁺)	calcd for C₁₀H₁₃NO₄P⁺ [M+H]⁺ 242.0577, found 242.0577

3-azido-1-(4,5-dichlorophenyl)pyrrolidin-2-one
Identifier	8a
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, CDCl₃)	δ 7.75 (d, J = 2.6 Hz, 1H), 7.47 (dd, J = 8.9, 2.6 Hz, 1H), 7.37 (d, J = 8.8 Hz, 1H), 4.26 (t, J = 8.4 Hz, 1H), 3.79 – 3.65 (m, 2H), 2.45 (dddd, J = 13.2, 8.4, 7.2, 3.4 Hz, 1H), 1.96 (dq, J = 13.2, 8.3 Hz, 1H)
MS (ESI⁺) m/z	271.01 [M+H]⁺

3-azido-1-phenylpyrrolidin-2-one
Identifier	8b
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, CDCl₃)	δ 7.60 – 7.53 (m, 2H), 7.36 – 7.29 (m, 2H), 7.14 – 7.09 (m, 1H), 4.27 (t, J = 8.4 Hz, 1H), 3.83 – 3.70 (m, 2H), 2.44 (dddd, J = 13.1, 8.3, 7.1, 3.5 Hz, 1H), 1.96 (dq, J = 13.1, 8.3 Hz, 1H)
¹³C NMR (126 MHz, CDCl₃)	δ 162.6, 138.7, 129.0 (2C), 125.3, 119.8 (2C), 60.5, 45.3, 25.2
MS (ESI⁺) m/z	203.09 [M+H]⁺

3-amino-1-(4,5-dichlorophenyl)pyrrolidin-2-one
Identifier	9a
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, CDCl₃)	δ 7.69 (d, J = 2.5 Hz, 1H), 7.52 – 7.40 (m, 1H), 7.31 (d, J = 8.8 Hz, 1H), 3.79 (dt, J = 26.7, 7.9 Hz, 2H), 3.65 (dd, J = 9.6, 4.0 Hz, 1H), 2.97 (bs, NH₂), 2.54 (m, 1H), 1.95 (m, 1H)
MS (ESI⁺) m/z	245.02 [M+H]⁺

3-amino-1-phenylpyrrolidin-2-one
Identifier	9b
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, CDCl₃)	δ 7.59 – 7.53 (m, 2H), 7.31 (t, J = 8.0 Hz, 2H), 7.09 (td, J = 7.4, 1.3 Hz, 1H), 4.10 (bs, NH₂), 3.76 – 3.66 (m, 2H), 3.62 (t, J = 9.3 Hz, 1H), 2.50 (m, 1H), 1.80 (m, 1H)
MS (ESI⁺) m/z	177.10 [M+H]⁺

diethyl [1-({[1-(3,4-dichlorophenyl)-2-oxopyrrolidin-3-yl]amino}carbonyl)-3-methylbutyl]phosphonate
Identifier	11a
MS (ESI⁺) m/z	479.13 [M+H]⁺

diethyl [1-({[1-phenyl-2-oxopyrrolidin-3-yl]amino}carbonyl)-3-methylbutyl]phosphonate
Identifier	11b
MS (ESI⁺) m/z	411.20 [M+H]⁺

[1-({[1-(3,4-dichlorophenyl)-2-oxopyrrolidin-3-yl]amino}carbonyl)-3-methylbutyl]phosphonic acid
Identifier	12a
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, DMSO)	δ 8.26 (d, J = 8.2 Hz, 1H, NH), 8.04 (d, J = 1.8 Hz, 1H), 7.64 (d, J = 2.1 Hz, 2H), 4.68 (dt, J = 10.3, 8.4 Hz, 1H), 3.81 (td, J = 9.3, 2.0 Hz, 1H), 3.74 (td, J = 9.4, 6.9 Hz, 1H), 2.70 (ddd, J = 21.8, 11.4, 3.2 Hz, 1H), 2.41 – 2.32 (m, 1H), 1.98 – 1.81 (m, 2H), 1.65 – 1.54 (m, 1H), 1.37 (dtd, J = 13.2, 9.7, 3.2 Hz, 1H), 0.86 (t, J = 7.0 Hz, 6H)
¹³C NMR (126 MHz, DMSO)	δ 172.5, 169.9, 139.7, 131.4, 130.8, 126.0, 120.8, 119.3, 51.6, 45.4, 44.7, 36.3, 26.3, 25.2, 23.6, 21.6
HRMS (ESI⁺)	calcd for C₁₆H₂₂Cl₂N₂O₅P⁺ [M+H]⁺ 423.0643, found 423.0634

[1-({[1-phenyl-2-oxopyrrolidin-3-yl]amino}carbonyl)-3-methylbutyl]phosphonic acid
Identifier	12b
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, DMSO)	δ 8.30 (d, J = 7.3 Hz, 1H, NH), 7.68 (d, J = 8.2 Hz, 2H), 7.38 (t, J = 7.8 Hz, 2H), 7.14 (t, J = 7.3 Hz, 1H), 4.39 (q, J = 8.8 Hz, 1H), 4.15 (bs, 2H, OH), 3.76 (dtd, J = 16.3, 9.3, 6.9 Hz, 2H), 2.73 (ddd, J = 21.6, 11.5, 3.2 Hz, 1H), 2.39 (dddd, J = 11.8, 9.2, 6.9, 2.4 Hz, 1H), 1.97 (dq, J = 12.2, 9.3 Hz, 1H), 1.83 (tdd, J = 12.1, 7.6, 4.4 Hz, 1H), 1.55 (tt, J = 12.4, 6.1 Hz, 1H), 1.38 (dtd, J = 13.2, 9.7, 3.3 Hz, 1H), 0.85 (d, J = 6.5 Hz, 6H)
¹³C NMR (126 MHz, DMSO)	δ 171.9, 170.0, 140.1, 129.2 (2C), 124.5, 119.7 (2C), 52.6, 46.1, 45.1, 36.8, 26.4, 25.7, 23.9, 21.8
HRMS (ESI⁺)	calcd for C₁₆H₂₄N₂O₅P⁺ [M+H]⁺ 355.1417, found 355.1416

ethyl 2-({[1-(3,4-dichlorophenyl)-2-oxopyrrolidin-3-yl]amino}carbonyl)-4-methylpentanoate
Identifier	14a
MS (ESI⁺) m/z	415.13 [M+H]⁺

ethyl 2-({[1-phenyl-2-oxopyrrolidin-3-yl]amino}carbonyl)-4-methylpentanoate
Identifier	14b
MS (ESI⁺) m/z	347.19 [M+H]⁺

N-hydroxy-2-({[1-(3,4-dichlorophenyl)-2-oxopyrrolidin-3-yl]amino}carbonyl)-4-methylpentanamide
Identifier	15a
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, Acetone)	δ 8.11 (d, J = 2.5 Hz, 1H), 7.68 (dt, J = 9.0, 2.1 Hz, 1H), 7.56 (dd, J = 8.9, 1.6 Hz, 1H), 4.70 – 4.59 (m, 1H), 3.94 – 3.86 (m, 2H), 3.16 (t, J = 7.7 Hz, 1H), 2.60 (s, 1H), 2.14 (d, J = 10.2 Hz, 1H), 1.81 – 1.67 (m, 2H), 1.62 (dt, J = 13.8, 6.9 Hz, 1H), 0.91 (d, J = 6.6 Hz, 6H)
¹³C NMR (126 MHz, Acetone)	δ 172.5, 170.3, 167.3, 139.7, 131.1, 126.8, 121.4, 120.6, 119.3, 52.8, 50.1, 45.7, 40.8, 26.6, 25.8, 22.4 (2C)
HRMS (ESI⁺)	calcd for C₁₇H₂₂Cl₂N₃O₄⁺ [M+H]⁺ 402.0982, found 402.0989

N-hydroxy-2-({[1-phenyl-2-oxopyrrolidin-3-yl]amino}carbonyl)-4-methylpentanamide
Identifier	15b
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, DMSO)	δ 10.50 (d, J = 1.7 Hz, 1H, NH), 8.98 (d, J = 1.6 Hz, 1H, OH), 8.11 (t, J = 7.6 Hz, 1H, NH), 7.67 (d, J = 8.1 Hz, 2H), 7.39 (t, J = 7.9 Hz, 2H), 7.15 (t, J = 7.4 Hz, 1H), 4.55 (dt, J = 10.3, 8.1 Hz, 1H), 3.77 (dd, J = 9.6, 4.2 Hz, 2H), 3.04 (t, J = 7.6 Hz, 1H), 2.39 (ddt, J = 12.9, 8.8, 4.4 Hz, 1H), 2.00 – 1.88 (m, 1H), 1.70 – 1.55 (m, 2H), 1.49 (hept, J = 6.8 Hz, 1H), 0.87 (d, J = 6.5 Hz, 6H)
¹³C NMR (126 MHz, DMSO)	δ 170.7, 168.6, 165.9, 138.9, 128.1 (2C), 123.6, 118.6 (2C), 51.1, 48.3, 43.8, 38.0, 24.9, 24.7, 21.9, 21.5
HRMS (ESI⁺)	calcd for C₁₇H₂₄N₃O₄⁺ [M+H]⁺ 334.1761, found 334.1754

3-[4-(dimethylaminomethyl)-1,2,3-triazol-1-yl]-1-(3,4-dichlorophenyl)pyrrolidin-2-one
Identifier	17a
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, MeOD)	δ 8.13 (s, 1H), 8.03 (d, J = 2.5 Hz, 1H), 7.62 (dd, J = 8.9, 2.6 Hz, 1H), 7.55 (d, J = 8.8 Hz, 1H), 5.72 (t, J = 9.4 Hz, 1H), 4.06 (dtd, J = 25.3, 9.4, 7.0 Hz, 2H), 3.75 (s, 2H), 2.96 – 2.86 (m, 1H), 2.84 – 2.72 (m, 1H), 2.35 (s, 6H)
¹³C NMR (126 MHz, MeOD)	δ 168.7, 142.8, 138.5, 132.2, 130.3, 128.1, 124.7, 121.6, 119.3, 61.7, 52.8, 45.2, 43.3 (2C), 25.4
HRMS (ESI⁺)	calcd for C₁₅H₁₈Cl₂N₅O⁺ [M+H]⁺ 354.0883, found 354.0876

3-[4-(dimethylaminomethyl)-1,2,3-triazol-1-yl]-1-phenylpyrrolidin-2-one
Identifier	17b
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, MeOD)	δ 8.14 (s, 1H), 7.72 – 7.63 (m, 2H), 7.47 – 7.39 (m, 2H), 7.24 (t, J = 7.4 Hz, 1H), 5.71 (t, J = 9.3 Hz, 1H), 4.16 – 4.04 (m, 2H), 3.77 (s, 2H), 2.98 – 2.86 (m, 1H), 2.79 (dq, J = 12.8, 9.0 Hz, 1H), 2.37 (s, 6H)
¹³C NMR (126 MHz, MeOD)	δ 169.9, 143.9, 140.1, 130.0 (2C), 126.9, 126.1, 121.9 (2C), 63.3, 54.1, 47.1, 44.7 (2C), 27.1
HRMS (ESI⁺)	calcd for C₁₅H₂₀N₅O⁺ [M+H]⁺ 286.1662, found 286.1660

[1-({[1-(4-benzamidophenyl)-2-oxopyrrolidin-3-yl]amino}carbonyl)-3-methylbutyl]phosphonic acid
Identifier	18a
Diastereomer ratio	α:β 70:30
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, MeOD)	δ 7.96 – 7.90 (m, 2H), 7.78 – 7.72 (m, 2H), 7.67 – 7.62 (m, 2H), 7.62 – 7.55 (m, 1H), 7.55 – 7.48 (m, 2H), 4.78 – 4.70 (m, 1H), 3.88 (dtt, J = 13.0, 9.5, 5.0 Hz, 2H), 2.97 (ddt, J = 22.2, 11.5, 3.8 Hz, 1H), 2.58 (dqd, J = 14.2, 7.1, 3.7 Hz, 1H), 2.19 – 2.01 (m, 2H), 1.75 – 1.65 (m, 1H), 1.58 (ddq, J = 14.0, 9.9, 5.0 Hz, 1H), 1.01 – 0.93 (m, 6H)
¹³C NMR (126 MHz, MeOD)	δ 173.5, 172.0, 168.8, 137.2, 136.9, 136.2, 132.9, 129.6 (2C), 128.6 (2C), 122.5 (2C), 122.1 (2C), 53.7, 46.9, 46.3, 37.1, 27.7, 26.8, 23.8, 21.8
HRMS (ESI⁺)	calcd for C₂₃H₂₉N₃O₆P⁺ [M+H]⁺ 474.1788, found 474.1785

[1-({[1-(4-benzamidophenyl)-2-oxopyrrolidin-3-yl]amino}carbonyl)-3-methylbutyl]phosphonic acid
Identifier	18b
Diastereomer ratio	α:β 0:100
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, MeOD)	δ 7.96 – 7.90 (m, 2H), 7.75 (dd, J = 8.7, 2.1 Hz, 2H), 7.65 (dd, J = 9.1, 2.1 Hz, 2H), 7.62 – 7.55 (m, 1H), 7.52 (td, J = 7.8, 2.0 Hz, 2H), 4.64 (t, J = 9.5 Hz, 1H), 3.95 – 3.84 (m, 2H), 2.94 (ddd, J = 22.4, 11.6, 3.0 Hz, 1H), 2.62 – 2.53 (m, 1H), 2.21 – 2.12 (m, 1H), 2.08 – 2.04 (m, 1H), 1.71 – 1.67 (m, 1H), 1.64 – 1.54 (m, 1H), 0.96 (td, J = 5.7, 1.8 Hz, 6H)
¹³C NMR (126 MHz, MeOD)	δ 173.7, 172.3, 168.8, 137.2, 136.9, 136.2, 132.9, 129.6 (2C), 128.6 (2C), 122.5 (2C), 122.2 (2C), 53.9, 47.1, 46.4, 37.3, 27.8, 26.6, 23.8, 21.7
HRMS (ESI⁺)	calcd for C₂₃H₂₉N₃O₆P⁺ [M+H]⁺ 474.1788, found 474.1783

[1-({[1-(4-(3-isopropylbenzamido)phenyl)-2-oxopyrrolidin-3-yl]amino}carbonyl)-3-methylbutyl]phosphonic acid
Identifier	19
Diastereomer ratio	α:β 60:40
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, DMSO)	δ 10.18 (s, 1H, NH), 8.32 (d, J = 7.3 Hz, 2H, OH), 8.23 (d, J = 8.2 Hz, 1H, NH), 7.89 (d, J = 7.9 Hz, 2H), 7.81 – 7.75 (m, 2H), 7.66 (d, J = 8.6 Hz, 2H), 7.39 (d, J = 7.9 Hz, 2H), 4.67 (q, J = 9.1 Hz, 1H- α), 4.40 (q, J = 8.8 Hz, 1H- β), 3.77 (hept, J = 8.4 Hz, 2H), 2.97 (h, J = 6.9 Hz, 1H), 2.73 (ddd, J = 22.3, 11.4, 3.2 Hz, 1H), 2.41 – 2.37 (m, 1H), 1.92 – 1.88 (m, 1H), 2.06 – 1.76 (m, 1H), 1.66 – 1.58 (m, 1H), 1.43 – 1.34 (m, 1H), 1.24 (d, J = 6.9 Hz, 6H), 0.90 – 0.83 (m, 6H)
¹³C NMR (126 MHz, DMSO)	δ 171.4, 169.3, 165.3, 152.2, 135.5, 135.3, 132.6, 127.8 (2C), 126.3 (2C), 120.5 (2C), 119.4 (2C), 51.3, 44.7, 44.5, 36.1, 33.4, 26.0, 25.5, 23.7 (2C), 23.5, 21.5
HRMS (ESI⁺)	calcd for C₂₆H₃₅N₃O₆P⁺ [M+H]⁺ 516.2261, found 516.2255

[1-({[1-(4-(thiophene-2-carboxamido)phenyl)-2-oxopyrrolidin-3-yl]amino}carbonyl)-3-methylbutyl]phosphonic acid
Identifier	20a
Diastereomer ratio	α:β 88:12
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, MeOD)	δ 7.93 – 7.86 (m, 1H), 7.74 – 7.68 (m, 3H), 7.67 – 7.56 (m, 2H), 7.18 (t, J = 3.7 Hz, 1H), 4.74 (t, J = 8.6 Hz, 1H), 3.94 – 3.82 (m, 2H), 2.95 (ddd, J = 22.5, 11.5, 3.2 Hz, 1H), 2.63 – 2.53 (m, 1H), 2.19 – 2.08 (m, 1H), 2.08 – 2.02 (m, 1H), 1.76 – 1.66 (m, 1H), 1.64 – 1.52 (m, 1H), 0.97 (dd, J = 6.6, 3.6 Hz, 6H)
¹³C NMR (126 MHz, MeOD)	δ 173.6, 172.3, 162.7, 140.8, 136.9, 136.9, 132.5, 130.1, 129.0, 122.4 (2C), 122.1 (2C), 53.7, 47.4, 46.9, 37.2, 27.7, 26.8, 23.8, 21.7
HRMS (ESI⁺)	calcd for C₂₁H₂₇N₃O₆PS⁺ [M+H]⁺ 480.1353, found 480.1359

[1-({[1-(4-(thiophene-2-carboxamido)phenyl)-2-oxopyrrolidin-3-yl]amino}carbonyl)-3-methylbutyl]phosphonic acid
Identifier	20b
Diastereomer ratio	α:β 0:100
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, MeOD)	δ 7.90 (dd, J = 3.8, 1.1 Hz, 1H), 7.75 – 7.69 (m, 3H), 7.68 – 7.61 (m, 2H), 7.18 (dd, J = 5.0, 3.8 Hz, 1H), 4.64 (t, J = 9.5 Hz, 1H), 3.95 – 3.84 (m, 2H), 2.93 (ddd, J = 22.2, 11.6, 3.2 Hz, 1H), 2.62 – 2.52 (m, 1H), 2.21 – 2.00 (m, 1H), 2.07 – 2.04 (m, 1H), 1.73 – 1.64 (m, 1H), 1.66 – 1.54 (m, 1H), 0.95 (dd, J = 6.5, 5.1 Hz, 6H)
¹³C NMR (126 MHz, MeOD)	δ 173.7, 172.4, 162.7, 140.8, 136.9, 136.9, 132.5, 130.1, 129.0, 122.4 (2C), 122.2 (2C), 53.9, 47.5, 47.1, 37.3, 27.9, 26.6, 23.8, 21.7
HRMS (ESI⁺)	calcd for C₂₁H₂₇N₃O₆PS⁺ [M+H]⁺ 480.1353, found 480.1358

[1-({[1-(4-(2-(4-chlorophenyl)acetamido)phenyl)-2-oxopyrrolidin-3-yl]amino}carbonyl)-3-methylbutyl]phosphonic acid
Identifier	21a
Diastereomer ratio	α:β 70:30
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, MeOD)	δ 7.58 (s, 4H), 7.33 (s, 4H), 4.71 (t, J = 9.5 Hz, 1H), 3.84 (dtt, J = 13.0, 9.5, 5.0 Hz, 2H), 3.67 (s, 2H), 2.95 (dd, J = 21.6, 10.3 Hz, 1H), 2.60 – 2.50 (m, 1H), 2.18 – 2.00 (m, 2H), 1.73 – 1.65 (m, 1H), 1.62 – 1.54 (m, 1H), 0.96 (dd, J = 6.5, 4.2 Hz, 6H)
¹³C NMR (126 MHz, MeOD)	δ 173.5, 172.2, 171.7, 137.1, 136.7, 135.6, 133.9, 131.8 (2C), 129.6 (2C), 122.2 (2C), 121.5 (2C), 53.7, 47.3, 46.9, 43.8, 37.1, 27.7, 26.8, 23.8, 21.7
HRMS (ESI⁺)	calcd for C₂₄H₃₀ClN₃O₆P⁺ [M+H]⁺ 522.1555, found 522.1568

[1-({[1-(4-(2-(4-chlorophenyl)acetamido)phenyl)-2-oxopyrrolidin-3-yl]amino}carbonyl)-3-methylbutyl]phosphonic acid
Identifier	21b
Diastereomer ratio	α:β 0:100
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, MeOD)	δ 7.59 (s, 4H), 7.33 (s, 4H), 4.72 (t, J = 9.5 Hz, 1H), 3.85 (ddt, J = 16.6, 9.7, 5.1 Hz, 2H), 3.67 (s, 2H), 2.94 (ddd, J = 22.3, 11.3, 3.2 Hz, 1H), 2.61 – 2.51 (m, 1H), 2.15 – 2.07 (m, 1H), 2.07 – 1.96 (m, 1H), 1.74 – 1.66 (m, 1H), 1.62 – 1.52 (m, 1H), 1.03 – 0.88 (m, 6H)
¹³C NMR (126 MHz, MeOD)	δ 173.5, 172.2, 171.2, 137.1, 136.7, 135.6, 133.9, 131.8 (2C), 129.6 (2C), 122.2 (2C), 121.5 (2C), 53.7, 47.4, 46.9, 43.8, 37.1, 27.7, 26.8, 23.8, 21.7
HRMS (ESI⁺)	calcd for C₂₄H₃₀ClN₃O₆P⁺ [M+H]⁺ 522.1555, found 522.1566

[1-({[1-(4-(2-phenylacetamido)phenyl)-2-oxopyrrolidin-3-yl]amino}carbonyl)-3-methylbutyl]phosphonic acid
Identifier	22
Diastereomer ratio	α:β 75:25
NMR reporting reference	Chemical shifts are given in parts per million (ppm) and referenced against the residual proton or carbon resonances of the >99 % deuterated solvents as internal standard
¹H NMR (500 MHz, MeOD)	δ 7.63 – 7.55 (m, 4H), 7.38 – 7.29 (m, 4H), 7.28 – 7.21 (m, 1H), 4.71 (t, J = 9.4 Hz, 1H), 3.91 – 3.80 (m, 2H), 3.67 (s, 2H), 2.93 – 2.84 (m, 1H), 2.57 – 2.53 (m, 1H), 2.16 – 2.03 (m, 2H), 1.72 – 1.68 (m, 1H), 1.61 – 1.58 (m, 1H), 0.98 – 0.90 (m, 6H)
¹³C NMR (126 MHz, MeOD)	δ 173.6, 172.3 (2C), 137.2, 136.8, 136.6, 130.1 (2C), 129.6 (2C), 128.0, 122.2 (2C), 121.5 (2C), 53.7, 47.8, 46.9, 44.7, 37.4, 27.9, 26.8, 23.8, 21.7
HRMS (ESI⁺)	calcd for C₂₄H₃₁N₃O₆P⁺ [M+H]⁺ 488.1945, found 488.1950

Final compounds
LC-MS purity (UV trace, 254 nm; area percentage method)	>95 %

LasB in complex with inhibitor 15b
PDB entry for final coordinates	9GM4
Single-crystal X-ray diffraction (100 K), resolution	1.5 Å
Single-crystal X-ray diffraction, observed diastereomer	Only the (R)-configured pyrrolidone diastereomer was observed in the co-crystal structure
Cα RMSD, LasB–15b versus LasB–thiol-based inhibitor complex (PDB 7NLM)	1.28 Å
Conformation comparison, LasB–15b versus LasB–thiol-based inhibitor complex (PDB 7NLM)	In the co-crystal structure with 15b, LasB adopts a distinctly more closed conformation than in the LasB structure with the thiol-based inhibitor
Asn112 side-chain distance, LasB–15b versus LasB–thiol-based inhibitor complex (PDB 7NLM)	2.5 Å
Cα RMSD, LasB–15b versus LasB–phosphonate-based inhibitor complex (PDB 8CC4)	0.64 Å
Cα RMSD, LasB–15b versus LasB–phosphonate-based dipeptide inhibitor complex (PDB 9FQD)	0.52 Å
Reporting qualifier	Statistics for the highest resolution shell are shown in parentheses
PDB code in data-collection and refinement statistics	8GM4
Space group	P 2₁ 2₁ 2₁
Cell dimensions, a, b, c (Å)	43.5, 52.2, 122.3
Cell dimensions, α, β, γ (°)	90.0, 90.0, 90.0
Wavelength (Å)	0.8856
Data collection, resolution (Å)	33.44 – 1.51 (1.57 – 1.51)
CC₁/₂	0.994 (0.808)
I/σI	8.0 (2.3)
Completeness (%)	99.8 (99.8)
Redundancy	4.6 (4.7)
Refinement, resolution (Å)	33.44 – 1.51
Refinement, number of reflections	44284 (4348)
Rwork / Rfree	0.152 / 0.170
Number of atoms	2736
Number of atoms, protein	2347
Number of atoms, ligand/ion	155
Number of atoms, water	315
B-factors	16.82
B-factors, protein	15.07
B-factors, ligand/ion	22.65
B-factors, water	28.51
R.m.s. deviations, bond lengths (Å)	0.009
R.m.s. deviations, bond angles (°)	1.00
MolProbity clash score	3.7
Ramachandran, favoured (%)	95.95
Ramachandran, allowed (%)	3.72
Ramachandran, outliers (%)	0.34