Hu Yan-Yun, Feng Li, Wang Jia, Zhang Xue-Jia, Wang Zhe, Tan Ning-Hua
Department of TCMs Pharmaceuticals, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, P. R. China.
Chem Biodivers. 2019 Jan;16(1):e1800438. doi: 10.1002/cbdv.201800438. Epub 2018 Dec 13.
Using the TLC cyclopeptide protosite detection method, a new cyclohexapeptide named rubipodanin B (1), together with 11 known Rubiaceae-type cyclopeptides (RAs), RA-X-OMe (2), RA-IV (3), RA-XI (4), RA-XIII-OMe (5), rubiyunnanin C (6), RA-I (7), RA-III (8), RA-V (9), RA-VII (10), RA-XII (11) and rubipodanin A (12), were obtained from the roots and rhizomes of Rubia podantha Diels. The structures were determined using various spectroscopic methods. Among them, 2 was firstly identified as a natural product, and 3-6 were firstly isolated from this species. Cytotoxicity and NF-κB signaling pathway activity of 1, 2, 4, 6, 7 and 9 were evaluated. All these compounds showed cytotoxic activities against three human tumor cell lines, MDA-MB-231, SW620 and HepG2, with the IC values between 0.015 and 10.27 μm, and only 7 and 9 possessed NF-κB inhibitory activities with the IC values of 2.42 and 0.046 μm, respectively, which demonstrated that 2-alanine amino acid plays a key role to maintain the RAs bioactivity.
采用薄层层析环肽原位点检测方法，从小花茜草（Rubia podantha Diels）的根及根茎中获得了一种名为茜草环己肽B（1）的新环六肽，以及11种已知的茜草科型环肽（RAs），即RA-X-OMe（2）、RA-IV（3）、RA-XI（4）、RA-XIII-OMe（5）、茜草云宁C（6）、RA-I（7）、RA-III（8）、RA-V（9）、RA-VII（10）、RA-XII（11）和茜草环己肽A（12）。通过各种光谱方法确定了它们的结构。其中，2首次被鉴定为天然产物，3 - 6首次从该物种中分离得到。评估了1、2、4、6、7和9的细胞毒性及NF-κB信号通路活性。所有这些化合物对三种人类肿瘤细胞系MDA-MB-231、SW620和HepG2均表现出细胞毒性，IC值在0.015至10.27μm之间，只有7和9具有NF-κB抑制活性，IC值分别为2.42和0.046μm，这表明2-丙氨酸对维持RAs的生物活性起着关键作用。
