Research Article

Acetylcholinesterase Inhibitory and Antioxidant Activity of the Compounds Isolated from Vanda roxburghii

Figure 3

Radical scavenging activity of the isolated compounds. (a) DPPH radical scavenging. IC50 (μg/ml): SA, 40.64 ± 1.68; VA, 19.64 ± 0.73; DC, 12.16 ± 0.55; GI, 4.16 ± 0.37; CA, 4.35 ± 0.09. (b) Hydroxyl radical scavenging. IC50 (μg/ml): SA, 91.05 ± 3.75; VA, 21.72 ± 0.87; DC, 15.07 ± 1.20; GI, 6.61 ± 0.76; CA, 9.32 ± 0.39. Catechin (CA) was used as a reference antioxidant. Results represent mean ± SD (n = 3). Compound 1 had no activity and was not shown. Means with different letters (a–e) differ significantly (). SA, syringaldehyde; VA, vanillin; DC, dihydroconiferyl dihydro-p-coumarate; GI, gigantol; CA, catechin.
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