一品红苞片花色素的分离及初步鉴定

用紫外-可见光分光光度计、高效液相色谱(HPLC)和质谱(MS)技术对一品红(Euphorbia pulcherrima)红色苞片中的花色素提取液进行了初步鉴定。一品红花色素的甲醇溶液分别在270、340 和520 nm 处有 3 个吸收峰; 在 440 nm 吸光度与可见光最大吸收波长 520 nm 吸光度的比值 为0.29; 花色素的甲醇溶液中加入AlCl3后发生红移, 再加入HCl后发生蓝移; 色素溶液在紫外光下无荧光; 色素样品经液相色谱分离后在 270 nm检测有 5 个比较明显的吸收峰; 质谱中得到 595、611、381、571 和 589 等对应的分子离子峰; 花色素酸解液高效液相色谱图谱和鼠李糖、葡萄糖的出峰时间一致。由这些结果可推断一品红花色素样品中主要含有 5 种组分: 矢车菊花色素芸香苷、飞燕草花色素芸香苷、飞燕草花色素苯甲酰基葡糖苷、矢车菊花色素苯甲酰基葡糖苷和一种未知成分。

The Extraction and Primary Identification of Anthocyanidin in Euphorbia pulcherrima

Anthocyanidins in Euphorbia pulcherrima were extracted and identified by use of UV-vis spectrophotometry, high performance liquid chromatography (HPLC) and mass spectrometry (MS). Anthocyanidin extract in methanol showed 3 absorption peaks, at 270, 340 and 520 nm, in the UV-vis spectrum, with bathochromic and hypsochromic shift with methanol+AlCl3 and methanol+AlCl3+HCl, respectively; the ratio of the absorbance at 440 nm to that at 520 nm was 0.29. No fluorescence occurred under UV irradiance, and 5 absorption peaks occurred at 270 nm after HPLC. Five molecular ion peaks (m/z) occurred on MS: 595, 381, 611, 587 and 571, respectively, and monosaccharides in the extract were identified as rhamuose and glucose on HPLC. These results suggest that anthocyanidin in E. pulcherrima mainly include cyanidin 3-rutinoside, delphinidin 3-rutinoside, cyanidin 3- benzoylglucoside, delphinidin 3-benzoylglucoside and an unknown component.