Table 2.

The minimum inhibitory concentration (MIC) for β-pinene quaternary ammonium salts against four bacteria.

Bacteria	The Value of MIC (μg/mL)
	4a	4b	4c	4d	4e	4f	Chloramphenicol
E. coli	2.5	20	80	160	160	320	5
P. aeruginosa	0.625	80	160	160	80	320	80
S. aureus	1.25	80	80	320	80	320	0.625
B. subtilis	1.25	5	80	160	160	640	0.625

Note: E. coli, Escherichia coli; P. aeruginosa, Pseudomonas aeruginosa; S. aureus, Staphylococcus aureus; B. subtilis, Bacillus subtilis.