In the past few decades, phenanthrenes have become of great interest from phytochemical and pharmacological points of view. To date, up to 90 phenanthrenes were isolated from eight Juncaceae species (Juncus acutus, J. effusus, J. inflexus, J. maritimus, J. roemerianus, J. setchuensis, J. subulatus, and Luzula luzuloides). These compounds are important chemotaxonomic markers, as the presence of a vinyl group in the molecule is characteristic only for Juncaceae phenanthrenes. The most important pharmacological effects of phenanthrenes are the antiproliferative, anti-inflammatory, antibacterial and spasmolytic activities. Previously, 15 phenanthrenes were isolated from J. inflexus and L. luzuloides by our group, several of them showed antibacterial and anti-inflammatory activites. In continuation of our studies on Juncaceae species, in the present paper we report on the investigation of J. compressus.
The dried plant material was extracted with methanol. After evaporation, it was subjected to solvent–solvent partition with n-hexane, CH2Cl2 and ethyl acetate. The CH2Cl2 fraction was chromatographed by combination of different methods, including polyamide CC, VLC, preparative TLC, Sephadex LH-20 gel filtration and HPLC. The structure elucidation was carried out by extensive spectroscopic analysis, using 1D and 2D NMR spectroscopy and HRMS experiments.
The results allowed the identification of nine phenanthrenes [1 phenanthrene (dehydroeffusol), 6 dihydrophenanthrenes (compressin A, effusol, effususol A, juncusol, 7-hydroxy-1-methyl-2-methoxy-5-vinyl-9,10-dihydrophenanthrene, 2-hydroxy-7-hydroxymethyl-1-methyl-5-vinyl-9,10-dihydrophenanthrene, and 2 phenanthrene dimers (compressin B, and effususin A]. Compressins A and B are new natural products. The isolated compounds are substituted with methyl, hydroxy, methoxy, hydroxymethyl, and vinyl groups. In cases of dimers, two juncusol or two effusol monomers are linked together via C-3 and C-3’. The position of vinyl group is C-5 in all cases. All compounds were isolated for the first time from J. compressus.
Acknowledgement: This work was supported by the GINOP-2.3.2-15-2016-00012.