Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Health Effects, State Key Laboratory of Tea Plant Biology and Utilization , Anhui Agricultural University , Hefei 230036 , China.
School of Traditional Chinese Pharmacy , China Pharmaceutical University , Nanjing 211198 , China.
Org Lett. 2019 Jul 5;21(13):5147-5151. doi: 10.1021/acs.orglett.9b01750. Epub 2019 Jun 20.
Racemic trimethylallantoin monomer (1), mesomeric and racemic trimethylallantoin dimers (2 and 3), were isolated from tea. Two pairs of optically pure enantiomers (1a, 1b and 3a, 3b) were separated by chiral column from the two racemes (1 and 3). Their structures were elucidated by a combination of extensive spectroscopic techniques, single-crystal X-ray diffraction, and experimental and calculated electronic circular dichroism. A novel caffeine catabolic pathway was proposed based on the caffeine stable isotopic tracer experiments.
从茶叶中分离得到外消旋三甲基海因单体（1）、mesomeric 和外消旋三甲基海因二聚体（2 和 3）。通过手性柱从两个外消旋体（1 和 3）中分离出两对光学纯对映异构体（1a、1b 和 3a、3b）。通过广泛的光谱技术、单晶 X 射线衍射以及实验和计算的电子圆二色谱的结合，确定了它们的结构。基于咖啡因稳定同位素示踪实验，提出了一种新的咖啡因代谢途径。
