Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstrasse 20, 38106 Braunschweig, Germany.
Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
Food Chem. 2015 Jul 15;179:278-89. doi: 10.1016/j.foodchem.2015.01.130. Epub 2015 Feb 4.
The main procyanidins, including dimeric B2 and B5, trimeric C1, tetrameric and pentameric procyanidins, were isolated from unroasted cocoa beans (Theobroma cacao L.) using various techniques of countercurrent chromatography, such as high-speed countercurrent chromatography (HSCCC), low-speed rotary countercurrent chromatography (LSRCCC) and spiral-coil LSRCCC. Furthermore, dimeric procyanidins B1 and B7, which are not present naturally in the analysed cocoa beans, were obtained after semisynthesis of cocoa bean polymers with (+)-catechin as nucleophile and separated by countercurrent chromatography. In this way, the isolation of dimeric procyanidin B1 in considerable amounts (500mg, purity>97%) was possible in a single run. This is the first report concerning the isolation and semisynthesis of dimeric to pentameric procyanidins from T. cacao by countercurrent chromatography. Additionally, the chemical structures of tetrameric (cinnamtannin A2) and pentameric procyanidins (cinnamtannin A3) were elucidated on the basis of (1)H NMR spectroscopy. Interflavanoid linkage was determined by NOE-correlations, for the first time.
从未烘焙的可可豆（可可树）中分离出主要的原花青素，包括二聚体 B2 和 B5、三聚体 C1、四聚体和五聚体原花青素，使用各种逆流色谱技术，如高速逆流色谱（HSCCC）、低速旋转逆流色谱（LSRCCC）和螺旋线圈 LSRCCC。此外，二聚体原花青素 B1 和 B7 在分析的可可豆中天然不存在，在用（+）-儿茶素作为亲核试剂对可可豆聚合物进行半合成后通过逆流色谱分离得到。通过这种方式，在单次运行中就可以相当数量（500mg，纯度>97%）分离出二聚体原花青素 B1。这是首次通过逆流色谱从可可树中分离和半合成二聚体到五聚体原花青素的报道。此外，基于（1）H NMR 光谱阐明了四聚体（肉桂单宁 A2）和五聚体原花青素（肉桂单宁 A3）的化学结构。首次通过 NOE 相关确定了间黄烷键。
