Antimicrobial activity of the synthesized non-allergenic urushiol derivatives

Figures & data

Fig. 1. Structure of synthetic catechol-type urushiol derivatives (1–6).

Table 1. Inhibition of food spoilage and pathogenic microorganisms by catechol-type urushiol derivatives (1–6).

Strains	Inhibition zone (mm)
	BA	1	2	3	4	5	6
Staphylococcus aureus KCTC 1927	15.1 ± 0.6^cd	10.0 ±1.0^b	15.3 ± 0.6^d	22.3 ± 0.6^c	11.7 ± 0.6^d	–	–
Staphylococcus epidermidis KCTC 1917	13.3 ± 0.6^b	11.7 ±0.6 ^bc	16.3 ± 2.1^de	22.0 ± 1.7^c	10.4 ± 1.0^c	–	–
Pseudomonas aeruginosa KCTC 2004	9.7 ± 0.6^a	10.7 ± 0.6^b	16.3 ± 0.6^e	18.7 ± 1.2^b	–	–	–
Escherichia coli KCTC 1924	14.3 ± 0.6^bc	12.7 ± 0.6^cd	16.3 ± 1.5^de	25.7 ± 1.0^d	10.7 ± 0.6^c	–	–
Bacillus subtilis KCTC 1021	13.7 ± 1.5^b	7.0 ± 0.1^a	7.0 ± 0.6^a	23.3 ± 2.1^c	8.0 ± 0.6^b	–	–
Salmonella enteric KCTC 3065	10.7 ± 0.6^a	13.0 ± 1.0^d	12.7 ± 1.5^c	19.3 ± 1.2^b	–	–	–
Streptococcus mutans KCTC 1925	10.7 ± 0.6^a	11.3 ± 0.6^bc	12.0 ± 1.0^c	22.3 ± 1.5^c	9.1 ± 0.6^b	–	–
Vibrio vulnificus KCTC 7965	10.7 ± 0.6^a	15.3 ± 0.6^e	19.0 ± 1.0^f	16.0 ± 1.0^a	–	–	–
Candida albicans KCTC 2959	10.0 ± 1.0^a	8.0 ± 1.0^a	10.0 ± 1.0^b	25.0 ± 1.0^d	–	–	–
Helicobacter pylori KCTC 5335		–	7.7 ± 0.6^a	31.5 ± 0.5^e	6.7 ± 0.6^a	8.0 ± 0.0	–

Notes: Compounds were assayed at the concentration of 5 μmol. BA: Benzoic acid was used as positive control. Nalidixic acid (inhibition zone, mm, 11.0 ± 0.2), erythromycin (7.0 ± 0.0), tetracycline (9.0 ± 0.0), and ampicillin (7.0 ± 0.0) were used as positive controls against H. pylori.–: No growth inhibition. Values represent mean ± standard deviation (n = 3). The different letters in the same column indicated a significant difference (p < 0.05) by the Tukey–Kramer test.

Table 2. MIC of catechol-type urushiol derivatives (1–6) against food spoilage and pathogenic microorganisms.

Strains	MIC (μmol/mL)
	BA	1	2	3	4	5	6
Staphylococcus aureus KCTC 1927	0.20 ± 0.0	0.59 ± 0.0	1.41 ± 0.0	0.39 ± 0.0	0.08 ± 0.0	0.09 ± 0.0	0.08 ± 0.0
Staphylococcus epidermidis KCTC 1917	0.37 ± 0.0	2.68 ± 0.0	2.22 ± 0.0	0.92 ± 0.0	0.04 ± 0.0	0.05 ± 0.0	0.11 ± 0.0
Pseudomonas aeruginosa KCTC 2004	0.25 ± 0.0	0.27 ± 0.0	1.93 ± 0.0	1.17 ± 0.0	0.12 ± 0.0	0.33 ± 0.0	0.50 ± 0.0
Escherichia coli KCTC 1924	0.61 ± 0.0	0.23 ± 0.0	0.20 ± 0.0	0.08 ± 0.0	0.04 ± 0.0	0.25 ± 0.01	0.18 ± 0.0
Bacillus subtilis KCTC 1021	0.70 ± 0.0	0.64 ± 0.0	0.60 ± 0.0	0.47 ± 0.0	0.16 ± 0.0	0.20 ± 0.0	0.26 ± 0.0
Salmonella enteric KCTC 3065	0.25 ± 0.0	0.59 ± 0.1	0.68 ± 0.2	0.36 ± 0.0	0.10 ± 0.0	0.23 ± 0.0	0.13 ± 0.03
Streptococcus mutans KCTC 1925	1.00 ± 0.0	0.77 ± 0.0	0.72 ± 0.0	0.50 ± 0.0	0.34 ± 0.0	0.22 ± 0.0	0.41 ± 0.0
Vibrio vulnificus KCTC 7965	0.82 ± 0.0	2.00 ± 0.0	2.01 ± 0.0	1.22 ± 0.0	0.96 ± 0.0	0.75 ± 0.0	0.64 ± 0.0
Candida albicans KCTC 2959	1.64 ± 0.0	1.68 ± 0.0	0.32 ± 0.0	0.11 ± 0.0	0.56 ± 0.0	0.47 ± 0.0	0.54 ± 0.0
Helicobacter pylori KCTC 5335		0.30 ± 0.13	0.27 ± 0.12	0.07 ± 0.0	0.04 ± 0.04	0.03 ± 0.02	0.03 ± 0.02

Notes: BA: Benzoic acid was used as positive control. Nalidixic acid (MIC, μmol/mL, 0.02 ± 0.01), erythromycin (0.03 ± 0.0), tetracycline (0.002 ± 0.0), and ampicillin (0.14 ± 0.0) were used as positive controls against H. pylori. Each value is the mean ± SD of three experiments.