title: Usnic Acid Derivatives with Cytotoxic and Antifungal Activities from the Lichen Usnea longissima.
abstract: Eight usnic acid derivatives, that is, usenamines A-F (1-6), usone (7), and isousone (8), together with the known (+)-usnic acid (9), were isolated from the lichen Usnea longissima. Their structures were elucidated using 1D and 2D NMR and MS data, and the absolute configurations of compounds 1 and 2 were defined by single-crystal X-ray diffraction analyses. Compounds 1, 2, and 8 showed inhibitory effects on the growth of human hepatoma HepG2 cells with IC50 values of 6.0-53.3 μM compared with methotrexate as the positive control, which had an IC50 value of 15.8 μM. Furthermore, 1 induced apoptosis of HepG2 cells in a dose-dependent manner at concentrations of 0-15.0 μM. The isolated compounds were also evaluated for their antifungal and antibacterial activities, with 7 and 8 exhibiting weak inhibitory effects on fungal Trichophyton rubrum spp. with an MIC value of 41.0 μM.
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine , Beijing 100029, People's Republic of China.|School of Chinese Materia Medica, Beijing University of Chinese Medicine , Beijing 100102, People's Republic of China.
authors.forename: Xuelong
authors.initials: X
authors.lastname: Yu
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine , Beijing 100029, People's Republic of China.|School of Chinese Materia Medica, Beijing University of Chinese Medicine , Beijing 100102, People's Republic of China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine , Beijing 100029, People's Republic of China.|School of Chinese Materia Medica, Beijing University of Chinese Medicine , Beijing 100102, People's Republic of China.
authors.forename: Guozhu
authors.initials: G
authors.lastname: Su
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine , Beijing 100029, People's Republic of China.|School of Chinese Materia Medica, Beijing University of Chinese Medicine , Beijing 100102, People's Republic of China.
authors.forename: Ailin
authors.initials: A
authors.lastname: Yang
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine , Beijing 100029, People's Republic of China.
authors.forename: Zhongdong
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine , Beijing 100029, People's Republic of China.
authors.forename: Changhai
authors.initials: C
authors.lastname: Qu
authors.affiliation: Department of Dermatology and Venereology, Peking University First Hospital, Research Center for Medical Mycology, Peking University , Beijing 100034, People's Republic of China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wan
authors.affiliation: Department of Dermatology and Venereology, Peking University First Hospital, Research Center for Medical Mycology, Peking University , Beijing 100034, People's Republic of China.
authors.forename: Ruoyu
authors.initials: R
authors.lastname: Li
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine , Beijing 100029, People's Republic of China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Tu
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine , Beijing 100029, People's Republic of China.
authors.forename: Xingyun
authors.initials: X
authors.lastname: Chai
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001572:Benzofurans / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D056945:Hep G2 Cells; D006801:Humans; D008727:Methotrexate / Q000494:pharmacology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D014249:Trichophyton / Q000187:drug effects; D020949:Usnea / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D000970:Antineoplastic Agents; D001572:Benzofurans; D004365:Drugs, Chinese Herbal; C073339:usnic acid; D008727:Methotrexate