Antifungal macrocyclic bis(bibenzyls) from the Chinese liverwort Ptagiochasm intermedlum L.
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.
Xie
Chun-Feng
CF
School of Pharmaceutical Sciences, Shandong University, Jinan, PR China.
Qu
Jian-Bo
JB
Wu
Xiu-Zhen
XZ
Liu
Na
N
Ji
Mei
M
Lou
Hong-Xiang
HX
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
D000935:Antifungal Agents; D004988:Ethers, Cyclic; C505660:riccardin C; D015725:Fluconazole