First Chemical Investigation of Korean Wild Mushroom, Amanita hemibapha subsp. javanica and the Identification of Anti- Helicobacter pylori Compounds

subsp. (Amanitaceae) is an edible Korean wild mushroom. subsp. is often confused with , known as the East Asian death cap, which is potentially fatal when ingested. This study aimed to conduct the first chemical investigation of subsp. , which resulted in the isolation of seven fatty acid derivatives ( - ) and three steroids ( - ) from the MeOH extract of its fruiting bodies, and their structures were determined by comparing their NMR spectroscopic data with those previously reported, along with the data from LC/MS. Compound was reported previously without the identification of its absolute configuration; its structure, including the absolute configuration was confirmed for the first time, in this study, by using H NMR and its fragmentation patterns in MS/MS data, and LC/MS analysis. A recently developed method using competing enantioselective acylation (CEA) coupled with LC/MS analysis was applied for determining the absolute configuration of compound , which revealed the 11 -configuration. In the anti- activity test, compound showed antibacterial activity against strain 51 with 38.0% inhibition, comparable to that of quercetin (34.4% inhibition) as a positive control. Specifically, compound displayed the most potent antibacterial activity against strain 51 with 80.5% inhibition at the final concentration of 100 μm with a MIC value of 72 μm. These findings suggested that the active compound is a natural antibiotic that may be used in the development of novel antibiotics against In addition, the first chemical investigation of subsp. revealed that this mushroom can serve as a promising natural source for the bioactive natural products.