Quinone Derivatives as Promising Anti-Helicobacter pylori Agents from Aerial Parts of Mitracarpus hirtus

Abstract

Seven new naphthoquinone diglycosides (1−7), three new anthraquinones (8−10), and eight known analogues were obtained from the aerial parts of Mitracarpus hirtus collected from West Africa in a bioassay-guided phytochemical investigation. All isolated compounds were elucidated by comparison with the literature and interpretation of spectroscopic data, and the absolute configurations of the new naphthoquinone diglycosides (1−10) were confirmed by chemical methods and ECD calculations. Notably, compound 1 was found to be the first naphthoquinone diglycoside containing carboxylic acid and isopentenyl side chains isolated from a species in the genus Mitracarpus. Compounds 6− 18 showed antibacterial activity against multiple Helicobacter pylori strains with MIC values ranging from 0.0625 to 64 μg/mL. Particularly, 1-hydroxybenzoisochromanquinone (17) and benzo[g]isoquinoline-5,10-dione (18), with MIC values of 0.0625 and 0.125 μg/mL, displayed 32−512-fold higher potencies than a positive control, metronidazole. Compound 18 also demonstrated high antibiofilm activity and killed biofilm-encased Helicobacter pylori cells more effectively than metronidazole.

Polyoxygenated (9β-H)-Pimarane Derivatives from Leaves of Icacina oliviformis and Their Anti-tumor Activities

“…A detailed description of acid hydrolysis was provided in our previous reports. [35] Briefly, the reaction mixtures (compound S146).…”

Exploring Anthraquinones as Antibacterial and Antifungal agents

“…The most active compound was anthraquinone‐2‐carboxylic acid 13 with very low MIC value of 0.25 μg/mL against Helicobacter pylori JRES00015 (Figure 2). [49] In another study, four hydroxy substituted anthraquinones isolated from the plant Spermacoce latifolia were studied for their inhibitory potential against plethora of bacteria. 2‐hydroxyanthraquinone 14 and digiferruginol 15 significantly inhibited Bacillus subtilis while compound 14 showed activity also against Bacillus cereus (Figure 2).…”