齿瓣石斛的化学成分及其抗氧化活性

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.

Constituents of Dendrobium devonianum and their antioxidant activity

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-1H-pyrido3,4-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. Conclusion: All these compounds were isolated from D. devonianum for the first time. Among them, compounds 5 and 9 had some antioxidant activity.