Lin Lie-Chwen, Kuo Yuh-Chi, Chou Cheng-Jen
National Research Institute of Chinese Medicine, 155-1, Sec. 2, Li-Nung Street, Taipei (112), Taiwan, Republic of China.
J Nat Prod. 2002 Apr;65(4):505-8. doi: 10.1021/np010414l.
Two new A-type proanthocyanidins have been isolated from Ecdysanthera utilis and identified as epicatechin-(4beta-->8,2beta-->O-->7)-epicatechin-(4beta-->8)-epicatechin (5) and epicatechin-(4beta-->8)-epicatechin-(4beta-->8,2beta-->O-->7)-epicatechin-(4beta-->8)-epicatechin (6), respectively. The structure-related components epicatechin (1), procyanidin B2 (2), proanthocyanidin A1 (3), proanthocyanidin A2 (4), and aesculitannin C (7) were also isolated. All of these compounds were identified and evaluated for immunopharmacological activity. Human peripheral blood mononuclear cells (PBMC) were used as target cells, and cell proliferation was determined by (3)H-thymidine uptake. The results indicated that compound 3 suppressed PBMC proliferation activated with phytohemagglutinin (PHA). The inhibitory mechanisms may involve the blocking of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) production, since compound 3 attenuated IL-2 and IFN-gamma production of PBMC in a dose-dependent manner. Therefore, it is suggested that immunomodulatory agents are present in E. utilis.
从黑鳗藤中分离出两种新的A型原花青素，分别鉴定为表儿茶素-(4β→8,2β→O→7)-表儿茶素-(4β→8)-表儿茶素(5)和表儿茶素-(4β→8)-表儿茶素-(4β→8,2β→O→7)-表儿茶素-(4β→8)-表儿茶素(6)。还分离出了与结构相关的成分表儿茶素(1)、原花青素B2(2)、原花青素A1(3)、原花青素A2(4)和七叶树鞣质C(7)。对所有这些化合物进行了鉴定并评估了其免疫药理活性。以人外周血单个核细胞(PBMC)作为靶细胞，通过³H-胸腺嘧啶核苷摄取来测定细胞增殖。结果表明，化合物3抑制了用植物血凝素(PHA)激活的PBMC增殖。其抑制机制可能涉及阻断白细胞介素-2(IL-2)和干扰素-γ(IFN-γ)的产生，因为化合物3以剂量依赖的方式减弱了PBMC中IL-2和IFN-γ的产生。因此，提示黑鳗藤中存在免疫调节因子。
