Table 3.

Inhibition and IC₅₀ values (µM) for tyrosinase, α-glucosidase, and aldose reductase (AR) and antioxidant activities of isolated compounds from Hypericum laricifolium Juss.

Compounds	α-glucosidase 1		AR 2		Antioxidants
					DPPH 3		ABTS 4
	Conc. (μg/mL)	IC50 (μM) 5	Conc. (μg/mL)	IC50 (μM)	Conc. (μg/mL)	IC50 (μM)	Conc. (μg/mL)	IC50 (μM)
Protocatechuic acid (1)	50	NA 6	10	16.9 ± 1.9 e	143	263.4 ± 0.2 e	17	9.7 ± 0.9 c
p-Hydroxybenzoic acid (2)	50	NA	10	NA	143	NA	33	NA
Chlorogenic acid (3)	50	NA	10	0.23 ± 1.8 a	143	123.1 ± 2.9 d	33	23.1 ± 3.5 f
Vanilic acid (4)	50	NA	10	NA	143	NA	33	NA
Caffeic acid (5)	50	NA	10	28.3 ± 0.9 f	143	47.2 ± 0.1 b	17	7.2 ± 1.1 b
Kaempferol 3-O-glucuronide (6)	50	NA	10	6.0 ± 1.1 c	143	58.8 ± 2.1 c	17	11.0 ± 0.2 d
Quercetin (7)	50	15.9 ± 1.2 a	10	2.5 ± 0.8 b	71	0.33 ± 1.4 a	17	0.33 ± 0.6 a
Kaempferol (8)	50	NA	10	9.7 ± 0.5 d	143	326.4 ± 3.3 f	33	191.8 ± 1.1 g
Acarbose	500	439.9 ± 8.9 b	-	-	-	-	-	-
Quercetin	-	-	10	2.4 ± 1.2 b	-	-	-	-
l-Ascorbic	-	-	-	-	71	0.57 ± 0.4 a	-	-
Trolox	-	-	-	-	-	-	17	18.8 ± 0.5 e

¹ The inhibition rates (%) were calculated at a concentration of 50 μg/mL except that for that of acarbose that was calculated at a concentration of 500 μg/mL. ² The inhibition rates (%) were calculated at a concentration of 10 μg/mL. ³ The inhibition rates (%) were calculated at a concentration of 143 μg/mL except for that of l-ascorbic acid that was calculated at a concentration of 71 μg/mL. ⁴ The inhibition rates (%) were calculated under the concentration of 17 μg/mL. ⁵ IC₅₀ value is defined as the half-maximal inhibitory concentration and data is presented as means ± SD (n = 3). ^a–g Different letters in the same column indicate significant differences, p < 0.05. ⁶ NA is not active.