天然棕色棉色素与白色棉棉籽壳色素成分的比较

Comparative study on pigment composition in natural brown cotton fiber and white cottonseed hulls

采用诊断试剂、紫外光谱、红外光谱对棕色棉色素和白棉棉籽壳色素的化学成分进行对比分析发现:棕色棉色素和白色棉棉籽壳色素为同一类物质,均为缩合单宁类化合物;2种色素的主要成分均含有邻二酚羟基结构,白色棉棉籽壳色素的主要成分还含有间苯三酚结构,而棕色棉色素中含间苯三酚结构的成分含量很低。另外,2种色素的高效液相色谱分离结果表明,白色棉棉籽壳色素提取物所含组分较多,而棕色棉色素主要有4种组分,2种色素并无分子结构完全一致的组分。

Pigments had been extracted from natural brown cotton fiber （NBCF） and delinted white cottonseed hulls （DWCH） by extensive use of diagnostic reagents, UV-VIS speetrophotometer, infrared absorption spectra and normal phase high-performance liquid chromatography （NP-HPLC） comparative analysis of their chemical compositions. The results of corresponding color reactions of two kinds of pigments showed that they were similar in main chemical constituents and all belonged to condensed tannins （CT）. The dominant ingredient of both two pigments were CT with pyrocatechol structure, the main ingredient of DWCH pigments also contained phloroglucinol structure while the content of the component with this structure was very small in NBCF pigments. The NP-HPLC method was developed to separate the two samples, the results showed that there were four compositions with one overwhelming in NBCF pigments, and various kinds of constituents were separated in DWCH pigments, however, constituents with the same molecular structure were not found in two pigments.