Phenolic composition and functional properties of wild mint (Mentha longifolia var. calliantha (Stapf) Briq.)

Figures & data

Table 1. Quantitative analysis for determination of phenolic components in the infusion and ethanol extract of M. longifolia.

		Samples		Analytical characteristics
No.	Phenolic compounds	Infusion	Ethanol extract	Linear range (ppm)	r^2	LOD (ppm)	LOQ (ppm)
1	Gallic acid	72 ± 4	2 ± 0.2	0.20–25.0	0.9993	0.075	0.227
2	Protocatechuic acid	6 ± 0.2	7 ± 0.2	0.20–25.0	0.9991	0.086	0.260
3	(+)-Catechin	nd	nd	0.90–113	0.9988	0.172	0.522
4	p-Hydroxybenzoic acid	nd	nd	0.20–25.0	0.9994	0.007	0.020
5	Chlorogenic acid	64 ± 1	27 ± 1	0.35–45.0	0.9988	0.080	0.241
6	Caffeic acid	119 ± 3	86 ± 2	0.16–21.0	0.9993	0.054	0.162
7	(−)-Epicatechin	nd	nd	0.50–66.0	0.9990	0.170	0.514
8	Syringic acid	33 ± 2	9 ± 0.1	0.05–12.0	0.9995	0.030	0.090
9	Vanillin	31 ± 1	6 ± 0.1	0.08–10.0	0.9995	0.020	0.060
10	p-Coumaric acid	15 ± 0.8	5 ± 0.1	0.04–6.0	0.9996	0.066	0.199
11	Ferulic acid	nd	nd	0.12–17.0	0.9993	0.004	0.011
12	Sinapic acid	7132 ± 32	4604 ± 27	0.12–17.0	0.9993	0.017	0.053
13	Benzoic acid	nd	nd	0.85–55.0	0.9998	0.111	0.335
14	o-Coumaric acid	328 ± 1.8	134 ± 0.7	0.24–32.0	0.9988	0.023	0.069
15	Rutin	96 ± 7	45 ± 1	0.40–56.0	0.9989	1.113	3.373
16	Hesperidin	481 ± 28	248 ± 2	0.43–55.0	0.9992	1.080	3.280
17	Rosmarinic acid	6260 ± 60	2225 ± 46	0.02–7.0	0.9998	0.148	0.447
18	Eriodictyol	14 ± 0.3	25 ± 0.3	0.33–21.0	0.9998	0.140	0.410
19	trans-Cinnamic acid	79 ± 2	15 ± 0.5	0.02–7.0	0.9998	0.148	0.447
20	Quercetin	nd	nd	0.40–55.0	0.9999	0.013	0.040
21	Luteolin	162 ± 4	84 ± 0.4	0.13–17.0	0.9999	0.020	0.060
22	Kaempferol	nd	nd	0.05–15.0	0.9996	0.021	0.062
23	Apigenin	124 ± 4	94 ± 4	0.17–11.0	0.9997	0.034	0.104

Figure 1. Phenolic compounds identified and quantified in infusion and ethanol extract of Mentha longifolia.

Table 2. Total bioactive compounds and total antioxidant activity of M. longifolia.

	Total bioactive compounds		Total antioxidant activity
Samples	Total phenolic (mg GAEs/g extract)^a	Total flavonoid (mg REs/g extract)^b	Phosphomolybdenum (mmol TEs/g extract)^c
Infusion	92.38 ± 0.43^d	46.18 ± 0.20	0.75 ± 0.02
Ethanol extract	67.05 ± 0.85	23.68 ± 0.20	0.64 ± 0.01

^aGAEs: Gallic acid equivalents.

^bREs: Rutin equivalents.

^cTEs: Trolox equivalents.

^dValues expressed are means ± SD of three parallel measurements.

Table 3. Radical scavenging activity of infusion and ethanol extract of M. longifolia.

	Radical scavenging activity
Samples	DPPH radical (mg TEs/g extract)^a	ABTS radical cation (mg TEs/g extract)^a
Infusion	195.96 ± 0.94^b	269.25 ± 9.04
Ethanol extract	162.08 ± 3.90	242.06 ± 1.53

^aTEs: Trolox equivalents.

^bValues expressed are means ± SD of three parallel measurements.

Table 4. Reducing power and metal chelating activity of the infusion and ethanol extract of M. longifolia.

	Reducing power activity		Metal chelating activity
Samples	CUPRAC (mg TEs/g sample)^a	FRAP (mg TEs/g sample)^a	Chelating effect (mg EDTAEs/g sample)^b
Infusion	454.99 ± 4.48^c	346.20 ± 0.17	7.31 ± 0.44
Ethanol extract	371.30 ± 5.21	239.87 ± 3.95	9.29 ± 0.24

^aTEs: Trolox equivalents.

^bEDTAEs: EDTA equivalents.

^cValues expressed are means ± SD of three parallel measurements.

Table 5. Enzyme inhibitory activities of the infusion and ethanol extract of M. longifolia.

	Anti-Alzheimer’s disease effect		Antidiabetic effect		Skin care effect
Samples	AChE inhibition (mg GALAEs/g sample)^a	BChE inhibition (mg GALAEs/g sample)^a	α-Amylase inhibition (mmol ACEs/g sample)^b	α-Glucosidase inhibition (mmol ACEs/g sample)^b	Tyrosinase inhibition (mg KAEs/g sample)^c
Infusion	1.32 ± 0.02^d	na^e	0.43 ± 0.04	5.90 ± 0.10	na
Ethanol extract	1.25 ± 0.01	na	0.59 ± 0.03	5.68 ± 0.18	na

^aGALAEs: Galantamine equivalents.

^bACEs: Acarbose equivalents.

^cKAEs: Kojic acid equivalents.

^dValues expressed are means ± SD of three parallel measurements.

^eNot active.