• Secondary Metabolites from Xylaria Endophytes: The isolation and structure elucidation of secondary metabolites from Xylaria endophytes by chemical and spectroscopic methods

      Maitland, Derek J.; Edwards, Raymond L.; Al-Busaidi, Harith
      This thesis describes the isolation and structure elucidation of secondary metabolites from a number of endophytic Xylaria fungi. Six Xylaria endophytes were surface cultured on an aqueous malt extract-glucose medium. The fungus A311R, from a palm tree in Thailand, produced nonane-1,2,3-tricarboxylic acid, which was isolated for the first time as a natural product. Also isolated from the same fungus was spiculisporic acid; the first instance of isolation from a Xylaria fungus. The fungus 6RD12 produced cycloepoxydon, which was isolated for the first time from a Xylaria fungus, and 4,5,6-trihydroxy-3-propyl-3,4,6,7-tetrahydro-l//-isochromen- 8(5//)-one, which is a novel compound. The fungi A217R and A517R produced cytochalasin D, (S)-mellein and (3S,4S)-4-hydroxymellein as main secondary metabolites suggesting that the two fungi are the same species. The fungus X04 (Xylaria cf. juruensis) produced 2-Hydroxy-5-ethoxy-3-methylcyclohexa-2,5-dien- 1,4-dione as a novel compound, coriloxin as the main secondary metabolite in addition to (R)-mellein and a mixture of two stereoisomers of the 4-Hydroxymellein. The fungus 6RD8 produced (S)-Omethylmellein as the main secondary metabolite. l
    • Secondary metabolites from Xylariaceous fungi. The isolation and structure elucidation of secondary metabolites from Xylariaceous fungi by chemical and spectroscopic methods.

      Maitland, Derek J.; Alhaidari, Rwaida A.A. (University of BradfordDivision of Chemical and Forensic Sciences, 2013-11-21)
      This thesis describes the isolation and structure elucidation of secondary metabolites formed in static culture from a number of endophytic Xylariaceous fungi. Four Xylaria endophytes isolated from a palm tree in Thailand were surface cultured on an aqueous malt extract-glucose medium. They all produced cytochalasin D, coriloxin, (S)-mellein and (3R,4R)-4-hydroxymellein as the main secondary metabolites suggesting that the four endophytes could be the same species. The endophytic fungus A116 produced cytochalasin D as the main secondary metabolite. Another non-endophytic fungus B315, produced cytochalasin D, (R)-mellein, a mixture of two isomers of 4-hydroxymellein and phloroglucinol. X.62, an endophytic fungus, produced 19,20-epoxycytochalasin C from the mycelium as the main secondary metabolite. The fungus Engleromyces sinensis produced engleromycin acetate as the main secondary metabolite. Fungus X. polymorpha produced (3E)-4-(3¿-acetyl-2¿,6¿-dihydroxy-5¿-methylphenyl)-2-methoxybut-3-enoic acid.