A new anti-Helicobacter pylori juglone from Reynoutria japonica

• Published in: Archives of pharmacal research Vol. 42; no. 6; pp. 505 - 511
• Main Authors: Khalil, Atif Ali Khan, Park, Woo Sung, Lee, Jeehoon, Kim, Hye-Jin, Akter, Kazi-Marjahan, Goo, Young-Min, Bae, Ji-Yeong, Chun, Man-Seog, Kim, Jung-Hwan, Ahn, Mi-Jeong
• Format: Journal Article
• Language: English
• Published: Seoul Pharmaceutical Society of Korea 01.06.2019; 대한약학회
• Subjects: anthraquinones; Anti-Bacterial Agents - isolation & purification; Anti-Bacterial Agents - pharmacology; antibacterial properties; carbon; clarithromycin; ethanol; Ethanol - chemistry; Helicobacter pylori; Helicobacter pylori - drug effects; juglone; Medicine; metronidazole; Microbial Sensitivity Tests; minimum inhibitory concentration; Naphthoquinones - isolation & purification; Naphthoquinones - pharmacology; nuclear magnetic resonance spectroscopy; Pharmacology/Toxicology; Pharmacy; phthalides; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; Plant Roots - chemistry; Polygonaceae - chemistry; Research Article; Reynoutria japonica; spectral analysis; stable isotopes; stilbenes; 약학; Juglone derivatives; activity; Anti; Anti-Helicobacter pylori activity; Reynoutria japonica
• ISSN: 0253-6269; 1976-3786; 1976-3786
• DOI: 10.1007/s12272-019-01160-x

A 70% ethanol extract from the root portion of Reynoutria japonica afforded one new and three known juglone derivatives, namely, 2-methoxy-6-acetyl-7-methyljuglone ( 1 ), 2-ethoxy-6-acetyl-7-methyljuglone ( 2 ), 2-methoxy-7-acetonyljuglone ( 3 ), and 3-acetyl-7-methoxy-2-methyljuglone ( 4 ) together with two phenolics ( 5 and 6 ), an anthraquinone ( 7 ), a stilbene ( 8 ) and a phthalide ( 9 ). Their structures were elucidated on the basis of comprehensive spectroscopic studies including IR, MS, and 1 H, 13 C, 2D NMR spectra. Compound 3 is a new compound in nature, and compounds 4 – 6 have been isolated for the first time from R. japonica . The isolates were evaluated for their antibacterial activity against three strains (43504, 51, and 26695) of Helicobacter pylori . The four isolated juglone derivatives ( 1 – 4 ) showed potent growth inhibitory activity. Among them, compounds 1 – 3 exhibited stronger inhibitory activity than those of the positive controls, juglone and metronidazole, for the three strains and that of another reference, clarithromycin, for the 43504 and 51 strains. Specifically, the new juglone compound 3 displayed the most potent antibacterial activity against all three strains, 43504, 51, and 26695, with MIC values of 0.06, 0.06 and 0.13 μM, respectively, and MIC 50 values of 0.14, 0.11 and 0.15 μM, respectively.