Synthesis and antioxidant activities of some new triheterocyclic compounds containing benzimidazole, thiophene, and 1,2,4-triazole rings

Figures & data

Scheme 1. The synthetic pathway for target compounds.

Table 1. Antioxidant activity values to CUPRAC method and SC₅₀ values to DPPH method of synthesized compounds.

Compound	CUPRAC method (mg TEAC/mg compound)	DPPH method (SC50 µg/mL)
2	0.037 ± 0.003	nd
3	0.036 ± 0.003	nd
4	0.946 ± 0.034	48.23 ± 1.26
5a	0.417 ± 0.013	89.39 ± 3.44
5b	1.327 ± 0.064	18.41 ± 0.13
5c	1.476 ± 0.025	9.89 ± 0.07
5d	0.712 ± 0.009	18.74 ± 0.19
5e	0.474 ± 0.013	18.34 ± 0.92
5f	0.665 ± 0.023	99.11 ± 3.25
5g	0.400 ± 0.072	90.01 ± 2.87
5h	1.341 ± 0.026	17.37 ± 0.07
6a	0.984 ± 0.018	53.33 ± 1.69
6b	0.980 ± 0.032	63.21 ± 2.11
6c	0.929 ± 0.032	58.73 ± 1.99
6d	0.951 ± 0.007	39.83 ± 0.89
6e	0.618 ± 0.066	94.13 ± 3.99
6f	1.304 ± 0.060	22.42 ± 0.56
6g	0.979 ± 0.006	96.47 ± 2.88
6h	0.494 ± 0.034	86.91 ± 4.41
Trolox	–	5.79 ± 0.05
Catechin	–	4.66 ± 0.03
Ascorbic acid	–	6.85 ± 0.04

nd, Not determined.

Table 2. ABTS radical scavenging activity values of the synthesized compounds.

	ABTS method % scavenging
Compound	6.25 (µg/mL)	3.13 (µg/mL)	1.56 (µg/mL)	0.78 (µg/mL)	0.39 (µg/mL)
2	nd	nd	nd	nd	nd
3	nd	nd	nd	nd	nd
4	89.72%	69.82%	39.47%	20.90%	15.92%
5a	89.51%	62.84%	39.39%	29.24%	14.14%
5b	89.55%	73.47%	40.30%	25.04%	17.74%
5c	89.72%	61.53%	35.32%	21.06%	12.11%
5d	89.99%	65.01%	41.46%	29.19%	22.06%
5e	86.73%	47.76%	21.23%	15.26%	10.45%
5f	87.56%	58.37%	39.47%	25.04%	19.73%
5g	55.22%	40.80%	34.00%	27.03%	7.96%
5h	91.51%	57.94%	33.02%	17.25%	11.96%
6a	89.39%	63.85%	35.66%	19.57%	12.44%
6b	89.72%	57.88%	32.01%	18.24%	7.13%
6c	89.39%	69.98%	38.14%	21.39%	6.80%
6d	88.72%	59.88%	34.66%	21.72%	16.42%
6e	53.90%	22.55%	11.94%	3.65%	1.00%
6f	89.22%	58.37%	35.66%	20.07%	16.92%
6g	56.72%	36.98%	24.54%	20.40%	7.30%
6h	60.75%	35.70%	17.08%	10.28%	3.32%
Trolox	91.35%	56.46%	42.58%	23.90%	6.46%
Catechin	91.07%	91.07%	85.99%	45.74%	23.49%
Ascorbic acid	91.21%	57.01%	26.65%	14.15%	7.55%

nd, Not determined.