齿瓣石斛的化学成分及其抗氧化活性

Constituents of Dendrobium devonianum and their antioxidant activity

目的:了解齿瓣石斛的化学成分,明确其功效的物质基础,为其开发利用提供依据。方法:运用硅胶、Rp-18(十八烷基硅烷)和凝胶柱色谱法分离纯化齿瓣石斛的化学成分,并根据其理化性质和波谱数据鉴定化合物结构。采用ABTS法对得到的酚酸类成分进行抗氧化活性筛选。结果:从齿瓣石斛的乙醇提取物中分离得到9个化合物,分别鉴定为2,3,4,9-四氢-1H-吡啶骈[3,4-b]吲哚-3-甲酸(1),脱氧胸腺嘧啶核苷(2),腺苷(3),N-反-对香豆酰酪胺(4),N-反-对阿魏酰酪胺(5),4-羟基-3-甲氧基苯甲醛(6),对羟基苯甲醛(7),3,4-二羟基苯甲酸甲酯(8)和4-羟基-3,5-二甲氧基苯甲酸(9)等9个化合物。其中化合物5有较好的清除抗氧化活性自由基(ABTS)的作用,其半数抑制率(IC50)为1.61 mmol·L-1;化合物9有较弱的清除抗氧化活性自由基(ABTS)的作用,其半数抑制率(IC50)为35.72 mmol·L-1。结论:所有化合物均为首次从齿瓣石斛中分离得到,其中化合物5和化合物9具有一定的抗氧化活性。

Objective： To 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. Method： The 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. Result： Nine compounds were isolated and identified as 2,3,4,9-tetrahydro-1 H-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 ICs0 1.61 mmol . L-1 , Compound 9 showed weak antioxidant activity with IC50 35.72 mmol.L-1. Conclusion： All these compounds were isolated from D. devonianum for the first time. Among them, compounds 5 and 9 had some antioxidant activity.