Anti-MRSA Compounds from Hericium erinaceus (Bull.:Fr.) Pers.

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is currently one of the most prevalent pathogens in nosocomial infections. Because hospital-acquired MRSA strains exhibit resistance to many antibiotics and are transmitted from patient to patient via transiently colonized hands of hospital personnel, MRSA infections pose a serious problem for hospitalized patients. We found that extracts of the fruiting bodies and the mycelia of Hericium erinaceus (Bull.:Fr.) Pers. exhibited anti-MRSA activity. Therefore, we tried to isolate the anti-MRSA compounds from the fungus. Isolation of the active compounds was guided by anti-MRSA activity. The fungus was cultivated by shaking at 30 °C for 4 weeks. The culture was centrifuged, and the resulting residue was extracted with 85% ethanol, and the extract, after evaporating the solvent, was partitioned between chloroform and water and then ethyl acetate and water. Repeated silica gel chromatography and HPLC of the chloroform-soluble and ethyl-acetate–soluble parts gave five active compounds. The fruiting bodies of the fungus were also extracted with 85% ethanol, and the extract was concentrated and fractionated by solvent partitions between chloroform and water, and then ethyl acetate and water. Repeated silica gel chromatography and HPLC of the chloroform-soluble part gave an anti-MRSA compound.