Gu Liwei, Kelm Mark, Hammerstone John F, Beecher Gary, Cunningham David, Vannozzi Sarah, Prior Ronald L
Arkansas Children's Nutrition Center, 1120 Marshall Street, Little Rock, Arkansas 72202, USA.
J Agric Food Chem. 2002 Aug 14;50(17):4852-60. doi: 10.1021/jf020214v.
The polymeric procyanidins were fractionated from lowbush blueberry on a Sephadex LH-20 column. The degree of polymerization (DP) for the polymers was determined by thiolysis to be in a range of 19.9 to 114.1. Normal-phase HPLC analysis indicated that the polymeric procyanidins did not contain oligomeric procyanidins with DP < 10. The polymers eluted as a single peak at the end of the chromatogram. The normal-phase HPLC gradient was modified to improve the separation of procyanidin monomers through decamers and to elute all the polymers beyond those as a distinct peak. Monomers through decamers were quantified individually. All the polymers (DP > 10) were quantified using a mixture of purified polymers as an external standard. Polymers were found to be the dominant procyanidins in brown sorghum bran, cranberry, and blueberry. Thiolysis of the polymer peaks indicated that epicatechin was present as extension units in these foods, however, the composition of terminal units varied considerably between catechin and epicatechin, or an A-type dimer linkage in the case of cranberry.
从矮丛蓝莓中在葡聚糖LH - 20柱上分离出聚合原花青素。通过硫解测定聚合物的聚合度（DP）在19.9至114.1范围内。正相高效液相色谱分析表明，聚合原花青素不包含DP < 10的低聚原花青素。聚合物在色谱图末端以单峰形式洗脱。对正相高效液相色谱梯度进行了修改，以改善原花青素单体至十聚体的分离，并将所有超过这些的聚合物作为一个明显的峰洗脱。分别对单体至十聚体进行定量。所有聚合物（DP > 10）使用纯化聚合物混合物作为外标进行定量。发现聚合物是棕色高粱麸、蔓越莓和蓝莓中主要的原花青素。聚合物峰的硫解表明，表儿茶素在这些食物中作为延伸单元存在，然而，在儿茶素和表儿茶素之间，末端单元的组成差异很大，对于蔓越莓而言是A型二聚体连接。
