title: Antifungal macrocyclic bis(bibenzyls) from the Chinese liverwort Ptagiochasm intermedlum L.
abstract: Six macrocyclic bis(bibenzyls) were obtained from the Chinese liverwort Ptagiochasm intermedlum L., and their structures were elucidated as pakyonol (1), neomarchantin A (2), isoriccardin C (3), marchantin H (4), riccardin F (5) and riccardin C (6) on the basis of spectroscopic data and comparison with known compounds. Among them, compounds 3-5 were isolated from this liverwort species for the first time. They possessed in vitro antifungal properties against the fluconazole-sensitive and resistant strains of Candida albicans, with minimum inhibitory concentrations (MICs) ranging from 32 to >512 microg mL(-1). Furthermore, riccardin C was also demonstrated to act as a fungal resistance modifying agent when its combined effect with fluconazole on three resistant strains of C. albicans was investigated. The synergistic or additive activity of riccardin C caused dramatically reduced MICs of fluconazole by at most 256-fold.
authors.affiliation: School of Pharmaceutical Sciences, Shandong University, Jinan, PR China.
authors.forename: Chun-Feng
authors.initials: CF
authors.lastname: Xie
authors.forename: Jian-Bo
authors.initials: JB
authors.lastname: Qu
authors.forename: Xiu-Zhen
authors.initials: XZ
authors.lastname: Wu
authors.forename: Na
authors.initials: N
authors.lastname: Liu
authors.forename: Mei
authors.initials: M
authors.lastname: Ji
authors.forename: Hong-Xiang
authors.initials: HX
authors.lastname: Lou
mesh_terms: D000935:Antifungal Agents / Q000302:isolation & purification* / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects*; D025141:Drug Resistance, Fungal; D004357:Drug Synergism; D004988:Ethers, Cyclic / Q000302:isolation & purification* / Q000494:pharmacology; D015725:Fluconazole / Q000494:pharmacology*; D035926:Hepatophyta / Q000737:chemistry*; D008826:Microbial Sensitivity Tests
chemical_list: D000935:Antifungal Agents; D004988:Ethers, Cyclic; C505660:riccardin C; D015725:Fluconazole