响应面优化铜藻(Sargassum horneri)中褐藻多酚的提取及其结构鉴定

Extraction Optimization Using Response Surface Methodology and Structure Identification of Phlorotannins from Sargassum horneri

目的:对铜藻(Sargassum horneri)中褐藻多酚的提取工艺条件进行优化,并对提取到的褐藻多酚进行初步的结构解析。方法:以褐藻多酚得率为指标,采用超声波辅助提取法,通过单因素试验及响应面分析,对褐藻多酚超声波辅助提取工艺中乙醇体积分数、液固比和超声提取时间三个参数进行了优化。分别采用Folin-Ciocalteu法、2,4-二甲氧基苯甲醛比色法(2,4-dimethoxybenzaldehyde assay,DMBA法)测定铜藻多酚提取物中总酚得率与褐藻多酚得率,计算得率并分析其相关性。对褐藻多酚提取物运用LC-TOF-MS鉴定其褐藻多酚的分子式并推测其结构。结果:响应面试验得到最佳提取条件是:乙醇体积分数为55%,液固比为42∶1 m L/g,超声提取时间为58 min。在优化条件下,铜藻中褐藻多酚得率为(25.16±0.34)mg/100 g。褐藻多酚得率与总酚得率有显著正相关关系(相关系数为0.803)。通过液相色谱仪联用四级杆串联飞行时间质谱仪(LC-TOF-MS)得到褐藻多酚是分子量为374.3036、分子式为C18H14O9的间苯三酚三聚体,推测其结构为Triphlorethol A。结论:通过研究提高了铜藻中褐藻多酚的得率;褐藻多酚得率和总酚得率有显著正相关性;铜藻中含有褐藻多酚Triphlorethol A。

Objective： To optimize extracting conditions of phlorotannins from Sargassum horneri using ultrasonic assisted extraction,making a preliminary structural analysis on the phlorotannin extraction. Method： Single-factor test and response surface methodology were applied to optimize three parameters,which were ethanol volume fraction,solid-liquid ratio and ultrasonic extraction time,for extracting phlorotannins from Sargassum horneri using the ultrasonic assisted extraction method.The content of total phenols in brown algae extracts was measured by Folin-Ciocalteu method,whilst that of phlorotannins were measured by 2,4-dimethoxybenzaldehyde assay（ DMBA assay）,and the correlation between the two was analyzed. The molecular formula of compounds in the phlorotannin extract was identified by LC-TOF-MS before speculating their structures.Result： The response surface interaction analysis showed that the optimum extraction conditions were ethanol volume fraction at55%,liquid-solid ratio at 42 ∶ 1 m L/g,extract time at 58 min. In this condition,the extraction yield of phlorotannins from Sargassum horneri was（ 25.16 ± 0.34） mg/100 g.The yield of phlorotannins measured by DMBA assay was positively correlated with the total phenol yield measured by the Folin-Ciocalteu method.（ The correlation coefficient 0.803） One compound in the extract was identified with molecular weight being 374.3036,and its molecular formula as C18 H14 O9. The trimer structure was assumed to be Triphlorethol A.Conclusion： The extraction yield of phlorotannins from Sargassum horneri was improved.The yield of phlorotannins and the yield of total phenols in Sargassum horneri extracts were positively correlated. Sargassum horneri contained phlorotannins Triphlorethol A.