Methods and Application of Food Composition Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD, 20705, USA.
Department of Chemistry & Biochemistry, College of Arts and Sciences, Ohio University, Athens, OH, 45701, USA.
Anal Bioanal Chem. 2020 Jun;412(15):3653-3662. doi: 10.1007/s00216-020-02601-z. Epub 2020 Apr 22.
Cranberry proanthocyanidin oligomers were investigated using ultra performance liquid chromatography-ion mobility-high-resolution mass spectrometry (UPLC-IM-HRMS). A total of 304 individual A-type and B-type proanthocyanidins, including 40 trimers, 68 tetramers, 53 pentamers, 54 hexamers, 49 heptamers, 28 octamers, and 12 nonamers, were characterized. A-type proanthocyanidins appeared to dominate the cranberry proanthocyanidins. As the degree of polymerization increased, the abundance of molecules with multiple A-type double inter-flavan linkage or having doubly charged ions also increased. Under the same charge state, the drift times of proanthocyanidin ions increased with their degree of polymerization or the number of double inter-flavan linkages. For the same proanthocyanidin molecules, doubly charged ions had shorter drift times compared to their singly charged counterparts, which lead to separated trendlines in the ion mobility-mass plot. While consistent ion mobility was observed for most proanthocyanidins with the same degree of polymerization, coeluted isomeric ions of trimer and tetramer were detected by their unique drift times. Incorporation of ion mobility into HRMS proved to be of great value to characterize and analyze proanthocyanidins from complex sample matrices. Graphical abstract.
采用超高效液相色谱-离子淌度-高分辨质谱（UPLC-IM-HRMS）研究了蔓越莓原花青素低聚物。共鉴定出 304 种 A 型和 B 型原花青素单体，包括 40 个三聚体、68 个四聚体、53 个五聚体、54 个六聚体、49 个七聚体、28 个八聚体和 12 个九聚体。A 型原花青素似乎占据了蔓越莓原花青素的主导地位。随着聚合度的增加，具有多个 A 型双黄烷醇键或具有双电荷离子的分子的丰度也增加。在相同的电荷状态下，原花青素离子的淌度随其聚合度或双黄烷醇键的数量增加而增加。对于相同的原花青素分子，双电荷离子的淌度比单电荷离子短，这导致在离子淌度-质荷比图中出现分离的趋势线。虽然大多数具有相同聚合度的原花青素表现出一致的离子淌度，但通过其独特的淌度检测到三聚体和四聚体的共洗脱异构体离子。将离子淌度纳入 HRMS 被证明对于从复杂的样品基质中表征和分析原花青素非常有价值。
