OBJECTIVETo study the chemical constituents of Dendrobium devonianum and identify the material basis components of its function, and then provide the basis for development and utilization of D. devonianum.

METHODThe constituents were separated and purified on the chromatography of silica gel, Sephadex LH-20 and RP-18 silica gel, and then their structures were elucidated based on the spectra data. ABTS method was used to evaluate the free radical scavenging activity of the phenolic compounds among them.

RESULTNine compounds were isolated and identified as 2,3,4,9-tetrahydro-1H-pyrido[3,4-b] indole-3-carboxylic acid (1), 2'-deoxythymidine (2), adenosine (3), N-trans-p-coumaroyl tyramine (4), N-trans-p-feruloyl tyramine (5), 3-methoxy-4-hydroxybenzaldehyde (6), 4-hydroxybenzaldehyde (7), 3,4-dihydroxybenzoic acid methyl ester (8), and 4-hydroxy-3,5-dimethoxybenzoic acid (9). Compound 5 showed good antioxidant activity with IC50 1. 61 mmol. L-1, Compound 9 showed weak antioxidant activity with IC50 35.72 mmol. L-1.

CONCLUSIONAll these compounds were isolated from D. devonianum for the first time. Among them, compounds 5 and 9 had some antioxidant activity.