Isolation and structrual elucidation of the secondary metabolites of trichoderma species; possible biological antagonists against the armillaria mellea
Swaleh, Sauda M.
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The thesis describes the extraction, isolation and structural elucidation of the secondary metabolites of Trichoderma isolates (T. longibrachiatum, Rifai and T. harzianum Rifai). The Trichordema culture broths were extracted with n-hexane, diethyl ether and ethyl acetate successively. The mycelium of T. harzianum was extracted by the above-mentioned solvents and also was extracted by the above-mentioned Solvents and also with methanol. The crude hexane and diethyl ether extracts of T.Longibrachiatum showed small but significant effects against the rhizomorphal vegetative radial growth of A. Mellea, a causal agent of the disease Armillaria root rot in tea plants. The crude ether, hexane mycelium and methanol extracts of T. harzianum also showed small by significant bioactive effects against the mycelia radial growth of A. mellea. Six purified substances were isolated from the various solvent extracts of T. longibrachiatum and T. Harzianum. The first substance was positively identified as 1,2- dinonyl phthalate whilst the second substance was partially identified as a long chain saturated hydrocarbon which may contain cyclic structures. The third substances was positively identified as butanedioic (succinic) acid. The fourth and fifth substances were partially identified as unsaturated monocarboxylic acids. The sixth was an interesting crystalline substance whose structure was not elucidated due to the puzzling spectral data. Structural elucidation of the compounds were determined by the spectral data analysis. 1H-nmr and 13C-nmr chemical shifts led to the formulation of the molecular structures which were confirmed by the characteristic fragmentation pattern show in the mass spectral data. Functional groups were inferred from the ir data.