Composition of Flavonoids in Lotus Pollen
Qian Wu, Shuai Shao, Shanshan Li, Huijin Zhang, Liangsheng Wang
Chinese Bulletin of Botany
2015, 50 ( 6):
721-732.
DOI: 10.11983/CBB14194
We used ultra-performance liquid chromatography-mass spectrometry (I-Class UPLC/Xevo TQ MS) to separate and identify the flavonoids in lotus pollens from 50 cultivars. Lotus pollen contains 13 flavonols and 2 flavones, all reported in lotus pollen for the first time. The most abundant flavonoids were quercetin glucosides, namely quercetin 3-O-glucuronide, quercetin 3-O-rhamnopyranosyl-(1→2)-glucopyranoside and quercetin 3-O-arabinopyranosyl-(1→2)- galactopyranoside, detected in all cultivar pollen. The total flavonoid (TF) content ranged from 82.64 to 281.08 mg∙100 g-1 in 50 cultivars, with Fei-Yun-Qian-Ye showing the highest TF and Xian-Nv-San-Hua the lowest. According to cluster analysis, 50 lotus cultivars were classified into four groups; group B contained more flavonoids than other groups, and group B TF content was the highest. TF content in Fei-Yun-Qian-Ye, Bo-Li-Xiao-Jie and Shu-Hong-Lian exceeded 200 mg∙100 g-1 dry weight and could be developed into lotus pollen products.
| Peak No. | Rt
(min) | UV λmax (nm) | ESI-NI (m/z) | ESI-PI (m/z) | Identification | References | | 1 | 2.04 | 248, 354 | 493[M-H]-, 317[A-H]- | 495[M+H]+, 319[A+H]+ | Myricetin 3-O-glucuronide | Chen et al., 2012a | | 2 | 2.18 | 248, 352 | 479[M-H]--, 316[A-2H]- | 481[M+H]+, 319[A+H]+ | Myricetin 3-O-glucoside | Deng et al., 2013 | | 3 | 2.23 | 248, 348 | 595[M-H]-, 300[A-2H]- | 597[M+H]+, 303[A+H]+ | Quercetin 3-O-arabino- pyranosyl-(1→2)-galacto- pyranoside | Chen et al., 2012a | | 4 | 2.37 | 248, 348 | 298[A-2H]- | 301[A+H]+ | Diosmetin derivative | | | 5 | 2.44 | 248, 348 | 477[M-H]-, 314[A-2H]- | 479[M+H]+, 317[A+H]+ | Isorhamnetin 3-O-glucoside | Li et al., 2014 | | 6 | 2.50 | 248, 348 | 607[M-H-CH3]-, 299[A-H]- | 463[M+H-146]+, 301[A+H]+ | Diosmetin 7-O-rhamnopy- ranosyl-(1→6)-glucopy- ranoside | Li et al., 2014 | | 7 | 2.63 | 248, 354 | 477[M-H]-, 301[A-H]- | 479[M+H]+, 303[A+H]+ | Quercetin 3-O-glucuronide | Deng et al., 2009 | | 8 | 2.74 | 248, 354 | 463[M-H]-, 300[A-2H]- | 487[M+Na]+, 465[M+H]+, 303[A+H]+ | Quercetin 3-O-galactoside | Deng et al., 2009 | | 9 | 2.80 | 248, 354 | 609[M-H]-, 301[A-H]- | 611[M+H]+, 303[A+H]+ | Quercetin 3-O-rhamnopy- ranosyl-(1→2)-glucopy- ranoside | Li et al., 2014 | | 10 | 3.13 | 248, 347 | 447[M-H]-, 284[A-2H]- | 449[M+H]+, 287[A+H]+ | Kaempferol 3-O-galactoside | Jung et al., 2003 | | 11 | 3.27 | 248, 348 | 461[M-H]-, 285[A-H]- | 463[M+H]+, 287[A+H]+ | Kaempferol 3-O-glucuronide | Chen et al., 2012a | | 12 | 3.37 | 248, 348 | 447[M-H]-, 284[A-2H]- | 471[M+Na]+, 287[A+H]+ | Kaempferol 3-O-glucoside | Yang et al., 2009 | | 13 | 3.49 | 248, 353 | 623[M-H]-, 477[M-H-146]-, 315[A-H]- | 625[M+H]+, 479[M+H-146]+, 317[A+H]+ | Isorhamnetin 3-O-rhamnopy- ranosyl-(1→6)-glucopy- ranoside | Chen et al., 2012a | | 14 | 3.63 | 248, 354 | 477[M-H]-, 314[A-2H]- | 479[M+H]+, 317[A+H]+ | Isorhamnetin 3-O-hexose | Lim et al., 2006 | | 15 | 3.71 | 248, 358 | 507[M-H]-, 344[A-2H]- | 509[M+H]+, 347[A+H]+ | Syringetin 3-O-glucoside | Guo et al., 2009 |
Table 1
I-Class UPLC/Xevo TQ MS analysis as well as the structure characterization and tentative identification of flavonols and flavonoids in lotus pollen
Extracts from the Article
在I-Class UPLC/Xevo TQ MS负离子模式下, 分子离子可以进一步被打碎, 得到二级甚至三级碎片离子, 这些碎片离子对类黄酮结构的鉴定有很大作用。表1列出了荷花花粉黄酮和黄酮醇的特征数据, 包括保留时间、最大吸收波长和质谱数据。据此, 在50个品种的荷花花粉中鉴定出15种黄酮和黄酮醇物质, 包括13种黄酮醇和2种黄酮。其化学结构式如图2。
3号峰在(-)ESI-MS负离子模式下具有高丰度离子碎片m/z 595[M-H]-和苷元离子碎片m/z 300 [A-2H]-, 在(+)ESI-MS正离子模式下有离子碎片m/z 597[M+H]+和苷元离子碎片m/z 303[A+H]+。9号峰在(-)ESI-MS负离子模式下具有高丰度的离子m/z 609 [M-H]-和苷元离子m/z 301[A-H]-, 在(+)ESI-MS正离子模式下有离子m/z 611[M+H]+和苷元离子m/z 303 [A+H]+。这两个化合物被鉴定为槲皮素-O-双糖苷类化合物。Ablajian等(2006)的研究表明, 此类化合物糖链部分为1→6连接有利于产生[M-H]-苷元离子, 而1→2连接更有利于产生[M-2H]-离子。据此, 峰3可鉴定为Quercetin 3-O-arabinopyranosyl-(1→2)-galac- topyranoside, 该化合物曾在荷叶、叶脉、花瓣、雄蕊、雌蕊、花托、莲房、莲子、叶柄和花柄中报道过(Kashiwada et al., 2005; Chen et al., 2012a)。峰9被鉴定为Quercetin 3-O-rhamnopyranosyl-(1→2)- glucopyranoside, 此化合物在莲子心中存在(Li et al., 2014)。
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