Three new phenanthrenes with antimicrobial activities from the aerial parts of Juncus effusus

Three new phenanthrenes (1-3), designated as 2-methoxy-1,6-dimethyl-5-vinyl-9, 10-dihydrophenanthren-7-ol, 1,6-dimethyl-4,5-dihydropyrene-2,7-diol and 1-(3,7- dihydroxy-2,8-dimethyl-9,10-dihydrophenanthren-1-yl)ethanone, were isolated from the aerial parts of Juncus effusus. Their structures were determined by extensive spectroscopic experiments (NMR and MS) and comparing with those related known compounds. The antifungal and antibacterial activities of 1-3 were evaluated. Compound 1 showed remarkable antifungal activities against six agricultural pathogenic fungi (Rhizoctonia solani, Verticillium dahliae Kleb, Sclerotinia sclerotiorum, Gibberella saubinetii, Bipolaris zeicola, and Phytophthora parasitica) with minimum inhibitory concentration (MIC) values ranging from 3.125 to 12.5 μg/mL, and also displayed significant antibacterial activities against two human pathogenic bacteria (Bacterium paratyphosum B and Micrococcus lysodeikticus) with MIC values of 12.5 and 25 μg/mL, respectively.