Antifungal Metabolite with a New Carbon Skeleton from Keissleriella sp. YS4108, a Marine Filamentous Fungus

Abstract

In addition to four known metabolites (4-acetyl-6,8-dihydroxy-5-methylisocoumarin, 6,8-dihydroxy-3-methylisocoumarin, 6,8-dihydroxy-3,5,7-trimethylisocoumarin and 3,3'-oxy-(5-methyl)-phenol), bioassay-guided fractionation of the culture of Keissleriella sp., a marine filamentous fungus (strain number: YS 4108), afforded an antifungal metabolite with a new carbon skeleton whose structure was elucidated spectrometrically as 3,6,8-trihydroxy-3-[3,5-dimethyl-2-oxo-3(E)-heptenyl]-2,3-dihydronaphthalen-1(4H)-one. In vitro antifungal assays of all isolates revealed that the new metabolite and 3,3'-oxybis[5-methylphenol] were inhibitory to the growth of the human pathogenic fungi Candida albicans, Tricophyton rubrum and Aspergillus niger with MICs of the former being 40, 20 and 80 microg/ml, and those of the latter 10, 30 and 50 microg/ml, respectively.

Antimicrobial potentials of endophytic fungi residing in Quercus variabilis and brefeldin A obtained from Cladosporium sp.

“…This is the first report of the isolation of the cytotoxin from Cladosporium sp. Antimicrobial activities of the chemicals biosynthesized by some plant endophytes have been studied by our group (Liu et al 2001;Liu et al 2002), and reported by a few other groups (Schulz et al 1995;McGee et al 1991). Our experimental results in this paper also prove this idea.…”

Free radical scavenging and antioxidant activities of EPS2, an exopolysaccharide produced by a marine filamentous fungus Keissleriella sp. YS 4108

“…YS 4108 was isolated using serial dilution methods described previously (Liu et al, 2002). Briefly, the marine sediment carrying Keissleriella sp.…”

Antimicrobial Activity of Callyspongia Diffusa (Marine Sponge) Associated Endophytic Bacteria L Strains

“…of seaweed Diginea sp [12], α-campholene aldehyde and Lucenin-2 from endophytic fungus aspergillus ochraceus MP2 of marine sponge [13], Ariakemicins A and B from endophytic bacteria Rapidithrixsp of marine source [14], 1-(2, 6-dihydroxyphenyl) pentan-1-one from endophytic bacteria Cryptopsoriopsissps of Clidamiahirta plant [15], 1, 3,8-Trihydroxy-6-methoxy anthraquinone from endophytic bacteria Curvularialunata of the marine sponge Niphatesolemda [16]. These are some important antimicrobial secondary metabolites obtained from marine sponge derived endophytic microbes.…”