棉酚旋光体柱前衍生化-HPLC分析与4个栽培棉种之间棉酚含量比较

Analysis for Gossypol Enantiomers Using Pre-Column Derivatization-High-Performance Liquid Chromatography and the Comparison of (-)/(+)-Gossypol Contents in Different Plant Parts among Four Cultivated Cotton Species

采用2%D-氨基丙醇+10%冰醋酸+88%乙腈作为棉酚提取和衍生化试剂对消旋棉酚和棉花样品进行热衍生化处理,用C18色谱柱和乙腈流动相进行高效液相色谱分析。该方法色谱结果表现为主峰清晰而杂峰少,左右旋棉酚出峰时间相差7 min,实验精度良好。用该方法对4个栽培种的25份材料的种仁和幼苗的根、茎、叶的左右旋棉酚含量进行了系统的检测。结果表明,海岛棉的种子和根系的总棉酚含量最高,其次是陆地棉;2个二倍体栽培棉种的种子和根系的总棉酚显著低于四倍体棉种,而2个二倍体栽培棉种的叶片总棉酚含量显著高于四倍体棉种。大多参试材料的种子和幼苗各部位的左右旋棉酚含量均有差异,其中海岛棉的左旋棉酚含量略高于右旋棉酚,陆地棉的右旋棉酚含量略高于左旋棉酚,而2个二倍体棉种的左旋棉酚只占总棉酚的1/3。无色素腺体棉的种仁和叶片中总棉酚含量极低,并以左旋棉酚为主,其种仁中只有左旋棉酚而无右旋棉酚;茎秆中总棉酚含量以及左右旋棉酚比例与一般有色素腺体常规棉相似,但根系中的总棉酚含量显著高于对应的有色素腺体棉,却以右旋棉酚为主。

Gossypol enantiomers of pure gossypol and cotton samples were analyzed by high-performance liquid chromatogra- phy, with a C18 chromatographic column and an acetonitrile mobile phase, using 2% D-aminopropanol, 10% acetic acid and 88% acetonitrile as gossypol extraction and derivatization reagents at 75 ℃ for 45 min. This method distinguished（--）-gossypol and （＋）-gossypol in cotton seeds and other plant parts. The chromatographic target peaks were very clear and there were few impurity-associated peaks. The first peak was （＋）-gossypol, and the（--）-gossypol peak appeared after 7 min. The （--）- and （＋）-gossypol contents in the seeds, roots, stems and leaves of the 25 genotypes belonging to 4 cultivated cotton species were systematically determined. The total gossypol content, （--）- and （＋）-gossypol, in the seeds and roots of Gossypium bar- badense was the highest, followed by that of Gossypium hirsutum. The total gossypol contents in the seeds and roots of the two diploid cotton species, Gossypium arboreum and Gossypium herbaceum, were significantly lower than those of the two te- traploid cotton species. However, the contentsin the leaves of the two diploid cotton species were much higher than those of the two tetraploid cotton species.There were some differences between the （-）-gossypol and （＋）-gossypol content in almost every plant part from all of the genotypes in the experiment. Among the four cultivated cotton species, the （--）-gossypol content in G. barbadense was slightly higher than that of （＋）-gossypol, while the opposite was true in G. hirsutum. However, the （＋）-gossy- pol content was much higher, being 2/3 of the total gossypol, than the （--）-gossypol content in most G. arboreum and G.herbaceum plant parts. The total gossypol contents, which contained mostly （--）-gossypol, in the seeds and leaves of glandless cotton were very low. There was no （＋）-gossypol in the glandless cotton seeds at all. The total gossypo! content and the ratio of the （--）/ （＋）-gossypols in the stems ofglandless cotton were almost the same as those ofglanded cotton, but the total gossypol contents and （＋）-gossypol proportion in the glandless cotton roots were much greater than those of glanded cotton.