Synthesis and Correlation of Aggregation and Antimicrobial Properties of Homochiral Quaternary Ammonium Bromides Derived from Camphoric Acid

Mikláš, R.; Miklášová, N.; Bukovský, M.

doi:10.2478/afpuc-2020-0017

Figures & Tables

Synthesis of QASs derived from (1R,3S)-(+)-camphoric acid.

Surface tension versus the logarithm of the aqueous molar concentration of 1a–1d at 25°C.

Variation of log CMC with chain length of 1a–1d at 25°C.

Correlation of CMC [mmolL−1] and MIC [mmolL−1] of QASs 1a–1d for a) S. aureus; b) E. coli; c) C. albicans.

Characterization of camphoric acid-derived QAS 1_

Compound	Formula / [α]_D²¹ (conc[g/100 mL]., solvent)	w_i(calc.)/%w_i(found)/%			Yield	M.p.
Compound	Formula / [α]_D²¹ (conc[g/100 mL]., solvent)	C	H	N	%	°C
1a	C₂₆H₄₉BrN₂O₂/+7.99 (0.85, CHCl₃)	62.2662.34	9.859.81	5.585.61	80	82–83.5
1b	C₂₈H₅₃BrN₂O₂/+6.75 (0.809, CHCl₃)	63.5063.26	10.099.96	5.295.15	87	85–85.5
1c	C₃₀H₅₇BrN₂O₂/+7.2 (c = 0.799, CHCl₃)	64.6164.36	10.309.96	5.024.85	84	95–96.8
1d	C₃₂H₆₁BrN₂O₂/+6,7d (c = 0.80, CHCl₃)	65.6265.68	10.5010.45	4.784.82	85	96.8–97.5

Minimal inhibitory concentrations [μmol L−1] of prepared QAS 1_

Compound	S. aureus CNCTC 29/58	E. coli CNCTC 377/79N	C. albicans CCM 8186
1a	6.1	24.3	12.2
1b	0.7	5.8	0.7
1c	0.6	5.5	0.6
1d	324.1	665.8	324.1
BAB	26	260	26

Spectroscopic data of camphoric acid-derived QASs 1_

Compound	Spectral data
1a	IR, ν˜ \tilde \nu /cm⁻¹: 2921, 2843, 1723, 1669, 1469, 1373, 1343, 1332, 1179, 1002, 929, 823, 724¹H NMR (300 MHz, CDCl₃) δ: 0.88 (t, 3H, J = 7.04 Hz), 0.95 (s, 3H), 0.99 (s, 3H), 1.20 (s, 3H), 1.26 (s, 13H), 1.37 (s, 4H), 1.77 (s, 2H, broad), 1.88–2.11 (m, 4H), 2.17–2.29 (m, 1H), 2.74 (d, 1H, J = 7.04 Hz), 3.51 (s, 6H), 3.60–3.70 (m, 4H), 4.11 (t, 2H, J = 8.21 Hz) ¹³C NMR (75 MHz, CDCl₃) δ: 13.9; 14.1; 19.5; 21.9; 22.7; 22.8; 25.1; 26.2; 29.2; 29.3; 29.4; 29.5; 29.6 (2C); 31.9; 32.9; 34.0; 44.7; 51.7 (2C); 54.6; 56.2; 60.0; 64.1; 176.0; 178.2
1b	IR, ν˜ \tilde \nu /cm⁻¹: 2919, 2849, 1723, 1668, 1469, 1373, 1344, 1331, 1179, 989, 927, 822, 723¹H NMR (300 MHz, CDCl₃) δ: 0.89 (t, 3H, J = 6.45 Hz), 0.96 (s, 3H), 0.99 (s, 3H), 1.21 (s, 3H), 1.27 (s, 15H), 1.38 (s, 4H), 1.74–2.12 (m, 8H), 2.19–2.33 (m, 1H), 2.76 (d, 1H, J = 6.45 Hz), 3.52 (s, 6H), 3.59–3.70 (m, 4H), 4.11 (t, 2H, J = 7.62 Hz)¹³C NMR (75 MHz, CDCl₃) δ: 13.9; 14.2; 19.5; 21.9; 22.7; 22.8; 25.1; 26.2; 29.3; 29.4 (2C); 29.5; 29.7 (4C); 31.9; 32.9; 34.0; 44.7; 51.8 (2C); 54.6; 56.2; 60.0; 64.1; 176.0; 178.3
1c	IR, ν˜ \tilde \nu /cm⁻¹: 2918, 2849, 1723, 1669, 1469, 1373, 1344, 1331, 1179, 990, 925, 820, 722¹H NMR (300 MHz, CDCl₃) δ: 0.88 (t, 3H, J = 6.45 Hz), 0.95 (s, 3H), 0.99 (s, 3H), 1.20 (s, 3H), 1.25 (s, 21H), 1.37 (s, 4H), 1.77 (s, 2H, broad), 1.85–2.11 (m, 4H), 2.17–2.30 (m, 1H), 2.75 (d, 1H, J = 6.45 Hz), 3.51 (s, 6H), 3.56–3.70 (m, 4H), 4.11 (t, 2H, J = 7.62 Hz)¹³C NMR (75 MHz, CDCl₃) δ: 13.9; 14.1; 19.5; 21.9; 22.7; 22.8; 25.1; 26.2; 29.3; 29.4 (2C); 29.5; 29.7 (6C); 31.9; 32.9; 34.0; 44.6; 51.7 (2C); 54.5; 56.2; 60.0; 64.1; 176.0; 178.2
1d	IR, ν˜ \tilde \nu /cm⁻¹: 2918, 2848, 1723, 1668, 1469, 1373, 1344, 1331, 1179, 1001, 927, 820, 721¹H NMR (300 MHz, CDCl₃) δ: 0.88 (t, 3H, J = 6.45 Hz), 0.95 (s, 3H), 0.99 (s, 3H), 1.20 (s, 3H), 1.25 (s, 27H), 1.37 (s, 2H), 1.77 (s, 2H, broad), 1.85–2.11 (m, 4H), 2.17–2.30 (m, 1H), 2.74 (d, 1H, J = 6.45 Hz), 3.51 (s, 6H), 3.59–3.70 (m, 4H), 4.11 (t, 2H, J = 7.04 Hz)¹³C NMR (75 MHz, CDCl₃) δ: 13.9; 14.1; 19.5; 21.9; 22.7; 22.8; 25.1; 26.2; 29.2; 29.4 (2C); 29.5; 29.7 (8C); 31.9; 32.9; 34.0; 44.6; 51.7 (2C); 54.5; 56.2; 60.0; 64.1; 176.0; 178.2

CMC, g(CMC) and pC20 values of prepared QASs calculated from tensiometry measurements_

	1a	1b	1c	1d
CMC [molL⁻¹]	5.07×10⁻³±0.23×10⁻³	9.13×10⁻⁴±0.98×10⁻⁴	0.97×10⁻⁴±0.05×10⁻⁴	8.09×10⁻⁶±1.13×10⁻⁶
γ_(CMC) [mNm⁻¹]	36.36	37.32	38.49	42.51
pC₂₀	3.5	4.1	5.1	5.5

Synthesis and Correlation of Aggregation and Antimicrobial Properties of Homochiral Quaternary Ammonium Bromides Derived from Camphoric Acid

Figures & Tables

Figure 1

Figure 2

Figure 3

Figure 4

Characterization of camphoric acid-derived QAS 1_

Minimal inhibitory concentrations [μmol L−1] of prepared QAS 1_

Spectroscopic data of camphoric acid-derived QASs 1_

CMC, g(CMC) and pC20 values of prepared QASs calculated from tensiometry measurements_

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