Tuenter Emmy, Ahmad Rizwan, Foubert Kenn, Amin Adnan, Orfanoudaki Maria, Cos Paul, Maes Louis, Apers Sandra, Pieters Luc, Exarchou Vassiliki
Natural Products & Food Research and Analysis (NatuRA), Department of Pharmaceutical Sciences, and ‡Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp , Universiteitsplein 1, 2610 Antwerp, Belgium.
J Nat Prod. 2016 Nov 23;79(11):2865-2872. doi: 10.1021/acs.jnatprod.6b00633. Epub 2016 Nov 10.
Nine cyclopeptide alkaloids (1-9), of which five (compounds 2, 3, 5, 8, and 9) are described herein for the first time, were isolated from roots of Ziziphus oxyphylla by means of conventional separation methods as well as semipreparative HPLC with DAD and ESIMS detection and LC-DAD-SPE-NMR. Structure elucidation was done by spectroscopic means. Nummularine-R (1), a previously known constituent from this species, was isolated along with its new derivatives O-desmethylnummularine-R (2) and O-desmethylnummularine-R N-oxide (3). In addition, the known compounds hemsine-A (4) and ramosine-A (6), as well as hemsine-A N-oxide (5), were isolated. Moreover, oxyphylline-C (7), a known constituent of Z. oxyphylla stems, was obtained, and two new compounds were identified, oxyphyllines-E (8) and -F (9). Just like oxyphylline-C, oxyphyllines-E and -F belong to the relatively rare class of neutral cyclopeptide alkaloids. The antiplasmodial activity and cytotoxicity of compounds 1, 2, 4, 6, and 9 were evaluated, and the most promising activity was found for O-desmethylnummularine-R (2), which exhibited an IC value of 3.2 ± 2.6 μM against Plasmodium falciparum K1, whereas an IC value of >64.0 μM was evident for its cytotoxicity against MRC-5 cells.
从尖叶枣的根中，通过常规分离方法以及配备二极管阵列检测（DAD）、电喷雾离子化质谱（ESIMS）的半制备高效液相色谱法（HPLC）和液相色谱-二极管阵列检测-固相萃取-核磁共振联用技术（LC-DAD-SPE-NMR），分离得到了9种环肽生物碱（1 - 9），其中5种（化合物2、3、5、8和9）在此首次被描述。通过光谱手段进行结构解析。从该物种中分离出了一种先前已知的成分——钱币树碱-R（1），以及它的新衍生物O-去甲基钱币树碱-R（2）和O-去甲基钱币树碱-R N-氧化物（3）。此外，还分离出了已知化合物血根碱-A（4）和拉莫辛-A（6），以及血根碱-A N-氧化物（5）。此外，还得到了尖叶枣茎中已知的成分——尖叶碱-C（7），并鉴定出了两种新化合物——尖叶碱-E（8）和尖叶碱-F（9）。与尖叶碱-C一样，尖叶碱-E和尖叶碱-F属于相对罕见的中性环肽生物碱类别。对化合物1、2、4、6和9的抗疟活性和细胞毒性进行了评估，发现最有前景的活性来自O-去甲基钱币树碱-R（2），其对恶性疟原虫K1的IC值为3.2 ± 2.6 μM，而其对MRC-5细胞的细胞毒性IC值>64.0 μM。
