Tazaki Hiroyuki, Ito Mayumi, Miyoshi Masako, Kawabata Jun, Fukushi Eri, Fujita Takashi, Motouri Mutsumi, Furuki Tatsuo, Nabeta Kensuke
Department of Bioresource Science, Obihiro University of Agriculture and Veterinary Medicine, Japan.
Biosci Biotechnol Biochem. 2002 Feb;66(2):255-61. doi: 10.1271/bbb.66.255.
The new caffeic acid derivative, subulatin (1), was isolated from in vitro cultured liverworts, Jungermannia subulata, Lophocolea heterophylla, and Scapania parvitexta. The structure of 1 involved two caffeic acids, D-glucose, and 2-carboxy-6-(1,2-dihydroxy-ethyl)-4,5-dihydroxy-5,6-dihydro-4H-pyran. The connectivity of those and the absolute stereochemistry of 1 were elucidated on the basis of spectroscopic evidence. The antioxidative activity of 1 was comparable to that of alpha-tocopherol. (2'R)-Phaselic acid (2a) and (-)-9,2''-epiphylloyl-L-malic acid (4) were also isolated from J. subulata and L. heterophylla, respectively. A chiral HPLC analysis of the p-bromobenzoyl-malic acids derived from 2a showed that 2a from J. subulata was unusual (+)-trans-caffeoyl-D-malic acid.
新的咖啡酸衍生物，subulatin（1），是从体外培养的地钱属植物——尖叶扁萼苔、异叶耳叶苔和小斑叶苔中分离得到的。化合物1的结构包含两个咖啡酸、D - 葡萄糖以及2 - 羧基 - 6 -（1,2 - 二羟基 - 乙基）- 4,5 - 二羟基 - 5,6 - 二氢 - 4H - 吡喃。基于光谱证据阐明了这些成分之间的连接方式以及化合物1的绝对立体化学结构。化合物1的抗氧化活性与α - 生育酚相当。（2'R）- 菜豆酸（2a）和（ - ）- 9,2'' - 表叶酰 - L - 苹果酸（4）也分别从尖叶扁萼苔和异叶耳叶苔中分离得到。对由2a衍生的对溴苯甲酰苹果酸进行手性高效液相色谱分析表明，来自尖叶扁萼苔的2a是不常见的（ + ）- 反式咖啡酰 - D - 苹果酸。
