Abstract
For an anti-plaque agent, two flavan-3-ols isolated from Theobroma cacao bean husk showed positive reactions with $H_2SO_4$-anisaldehyde solution, $FeCl_3$, and were identified as monomeric, dimeric flavan-3-ots in TLC. They were (-)-epicatechin and procyanidin B-2(epicatechin-(4$\beta$$\rightarrow$8)-epicatechin). The structures were established by spectroscopic and chemical methods. (-)-Epicatechin had moderate inhibitory activity on GTase at concentration of 1.0mM while procyanidin B-2 showed complete inhibition activity at the same concentration. The hydroxyl group of flavan-3-ol was supposed to be the essential element for inhibition on GTase.
Cacao bean외피로부터 분리된 물질은 anisaldehyde-$H_2SO_4$ 및 $FeCl_3$에 각각 갈색 및 청색반응을 하였고 TLC상에서 monomer 및 dimer의 fIavan-3-ol 물질로 확인되었다. 물질의 구조를 NMR로 검정한 결과 compound I 과 II 는 각각 (-)-epicatechin과 epicatechin-(4${\alpha}$$\rightarrow$8)-epicatechin의 결합 화합물인 procyanidin B-2이었다. 분리된 두 화합물은 GTase에 대해 높은 저해활성이 있었고 특히 procyanidin B-2는 1.0mM에서 완전히 저해시켰다. 이것은 f1avan-3-ol 구조내에 OH가의 증가에 따라 GTase 저해활성도 높아지는 것으로 추정되었다.