Extracts of Opuntia stricta var. dillenii fruits were fractionated by semi-preparative high-performance countercurrent chromatography (HPCCC) to study the secondary metabolite formation, whereby HPCCC showed a superior separation capacity to fractionate minor metabolites compared to HPLC. A family of new peptides was detected in semi-polar fractions when monitoring the HPCCC separation by off-line injections of fractions to ESI-MS/MS. Planar structures of the major compounds, two 14-ring-membered cyclopeptide alkaloids, which were named opuntisines A and B, were elucidated by 1D- and 2D-NMR spectroscopy and HR-ESI-MS/MS spectrometry, while a combination of chemical derivatisation and degradation revealed the stereo-configurations. Specifically, the methods of Marfey and Mosher indicated l-Glu, l-Ile, l-Phe and 1S-configurations, respectively; ROESY correlations revealed 8S,9S.

The novel opuntisine A showed moderate activity against the Gram-negative bacterium Escherichia coli, but no further antibacterial, antifungal nor cytotoxic effects. This bioactive natural product class is reported for the first time in the plant family Cactaceae.

仙人掌提取物。半制备高效逆流色谱法分离莳萝果实（HPCCC）研究次生代谢物的形成，与HPLC相比，HPCCC表现出了更好的分离次要代谢物的分离能力。通过将组分离线注射到ESI-MS / MS监测HPCCC分离时，在半极性组分中检测到一系列新肽。通过1D和2D-NMR光谱以及HR-ESI-MS / MS光谱，结合化学衍生化，阐明了主要化合物的平面结构，两个14个环成员的环肽生物碱，分别称为opuntisines A和B.和退化揭示了立体声配置。具体而言，Marfey和Mosher的方法显示1 -Glu，1 -Ile，1- Phe和1 S-分别配置；ROESY相关揭示8小号，9小号。

新型的opuntisine A对革兰氏阴性细菌大肠杆菌具有中等活性，但没有进一步的抗菌，抗真菌或细胞毒性作用。这种生物活性天然产物类别是仙人掌科植物中首次报道的。