One new pyrrole alkaloid 2-[2-formyl-5-(methoxymethyl)-1H-pyrrol-1-yl]acetic acid (1), together with two known ones, 4-[2-formyl-5-(methoxymethyl)-1H-pyrrol-1-yl]butanoic acid (2) and 4-[2-formyl-5- (hydroxymethyl)-1H-pyrrol-1-yl]butanoic acid (3), were isolated from the fruiting bodies of Leccinum extremiorientale for the first time. Their structures were identified on the basis of 1D and 2D NMR spectroscopy as well as MS. © 2015 Springer Science+Business Media New York.