Anti-Helicobacter pylori flavonoids from licorice extract.
Licorice is the most used crude drug in Kampo medicines (traditional Chinese medicines modified in Japan). The extract of the medicinal plant is also used as the basis of anti-ulcer medicines for treatment of peptic ulcer. Among the chemical constituents of the plant, glabridin and glabrene (components of Glycyrrhiza glabra), licochalcone A (G. inflata), licoricidin and licoisoflavone B (G. uralensis) exhibited inhibitory activity against the growth of Helicobacter pylori in vitro. These flavonoids also showed anti-H. pylori activity against a clarithromycin (CLAR) and amoxicillin (AMOX)-resistant strain. We also investigated the methanol extract of G. uralensis. From the extract, three new isoflavonoids (3-arylcoumarin, pterocarpan, and isoflavan) with a pyran ring, gancaonols A[bond]C, were isolated together with 15 known flavonoids. Among these compounds, vestitol, licoricone, 1-methoxyphaseollidin and gancaonol C exhibited anti-H. pylori activity against the CLAR and AMOX-resistant strain as well as four CLAR (AMOX)-sensitive strains. Glycyrin, formononetin, isolicoflavonol, glyasperin D, 6,8-diprenylorobol, gancaonin I, dihydrolicoisoflavone A, and gancaonol B possessed weaker anti-H. pylori activity. These compounds may be useful chemopreventive agents for peptic ulcer or gastric cancer in H. pylori-infected individuals.
Fukai
Toshio
T
Department of Physico-chemical Analysis, School of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan. fukai@phar.toho-u.ac.jp
Marumo
Ai
A
Kaitou
Kiyoshi
K
Kanda
Toshihisa
T
Terada
Sumio
S
Nomura
Taro
T
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003470:Culture Media; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D006035:Glycyrrhiza / Q000737:chemistry*; D016480:Helicobacter pylori / Q000187:drug effects*; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D010636:Phenols / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
D000900:Anti-Bacterial Agents; D003470:Culture Media; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; C464907:gancaonol A; C464908:gancaonol B; C464909:gancaonol C