Anthraquinones with antibacterial activities from Crucianella maritima L. growing in Egypt

From the extracts of Crucianella maritima L. (Rubiaceae), five new anthraquinones namely; 1-hydroxy-2-methyl-6-methoxy anthraquinone, 6-methoxy-2-methyl quinizarin, 6-methyl-anthragallol-2,3-dimethyl ether, 6-methyl-anthragallol-2-methyl ether, and 1-hydroxy-2-carbomethoxyanthraquinone were isolated and identified. In addition, deacetyl asperulosidic acid 6′-glucoside sodium salt, a new iridoid diglucoside, along with twelve known anthraquinones, three flavonols, three sterols, and one triterpene were also isolated and identified for the first time from this plant. Their chemical structures were established by physical, chemical and spectroscopic data, including UV, MS, ID- and 2D-NMR analyses. The antimicrobial, cytotoxic activities and a preliminary clinical trial of the crude extracts and some isolates are also presented. Chemotaxonomical aspects are briefly discussed.