title: Two New Diphenylketones and a New Xanthone from Talaromyces islandicus EN-501, an Endophytic Fungus Derived from the Marine Red Alga Laurencia okamurai.
abstract: Two new diphenylketones (1and2), a new xanthone (3), and a known xanthone analogue (4) were isolated and identified fromTalaromyces islandicusEN-501, an endophytic fungus obtained from the fresh collected marine red algaLaurencia okamurai. Their structures were elucidated on the basis of NMR spectroscopic and X-ray crystallographic analysis. The joint isolation of benzophenones and xanthones from the same fungal strain supports the biogenesis of xanthones via a benzophenone intermediate. It is worth mentioning that xanthones3and4have a methyl group at C-6 and C-2, respectively, which is uncommon compared with typical xanthones usually having a methyl group at C-8. Compounds1-4exhibited potent antioxidative activities against DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonate) radicals with IC50values ranging from 0.58 to 6.92 μg/mL, which are stronger than that of the positive controls BHT (butylated hydroxytoluene) and ascorbic acid. Compounds1,3, and4also showed inhibitory activities against several pathogenic bacteria.
authors.affiliation: Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Nanhai Road 7, Qingdao 266071, China. lihonglei428@126.com.|University of Chinese Academy of Sciences, Yuquan Road 19A, Beijing 100049, China. lihonglei428@126.com.
authors.forename: Hong-Lei
authors.initials: HL
authors.lastname: Li
authors.affiliation: Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Nanhai Road 7, Qingdao 266071, China. lixmqdio@126.com.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Li
authors.affiliation: Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Nanhai Road 7, Qingdao 266071, China. liuhui625@163.com.|University of Chinese Academy of Sciences, Yuquan Road 19A, Beijing 100049, China. liuhui625@163.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.affiliation: Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Nanhai Road 7, Qingdao 266071, China. menglh@ms.qdio.ac.cn.
authors.forename: Ling-Hong
authors.initials: LH
authors.lastname: Meng
authors.affiliation: Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Nanhai Road 7, Qingdao 266071, China. wangbg@ms.qdio.ac.cn.
authors.forename: Bin-Gui
authors.initials: BG
authors.lastname: Wang
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry; D001419:Bacteria / Q000187:drug effects; D001577:Benzophenones / Q000737:chemistry; D052160:Benzothiazoles / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry* / Q000494:pharmacology; D002084:Butylated Hydroxytoluene / Q000737:chemistry; D007659:Ketones / Q000737:chemistry* / Q000494:pharmacology; D044722:Laurencia / Q000737:chemistry*; D010851:Picrates / Q000737:chemistry; D000461:Rhodophyta / Q000737:chemistry*; D013451:Sulfonic Acids / Q000737:chemistry; D032901:Talaromyces / Q000737:chemistry*; D044004:Xanthones / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D001205:Ascorbic Acid; D001577:Benzophenones; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D002084:Butylated Hydroxytoluene; D007659:Ketones; D010851:Picrates; D013451:Sulfonic Acids; D044004:Xanthones; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C010574:biphenyl; C009689:xanthone; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: Laurencia okamurai; Talaromyces islandicus; antibacterial activity; antioxidative activity; diphenylketone; xanthone