| abstract |
An anti-Helicobacter pylori agent comprising a compound represented by the formula: wherein A represents an aromatic ring group which may be substituted; R1 and R2, whether identical or not, each represent a hydrogen atom or a hydrocarbon group which may be substituted; R3 and R4, whether identical or not, each represent a hydrogen atom, a hydrocarbon group which may be substituted, an acyl group, a carbamoyl group which may be substituted, or a carboxyl group which may be esterified; or a salt thereof. |