Isolatıon of secondary metabolites from Reddellomyces parvulosporus and Reddellomyces westraliensis species, structure elucidation and investigation of biological activities

In this PhD thesis, it was aimed to determine the chemical composition and biological activities of Reddellomyces parvulosporus and Reddellomyces westraliensis truffle mushrooms, which have not been researched before, naturally spread in our country, have edible and commercial potential. After determining the total phenolic amount of hexane, chloroform, acetone, methanol and water extracts obtained from both truffle species by extraction under room conditions as equivalent to pyrocatechol, the antioxidant activities of each extract were determined by the β-carotene bleaching, DPPH free radical scavenging, ABTS cation radical scavenging, CUPRAC and metal chelating assays, while acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzyme inhibition activities were determined by Ellman method. Also, cytotoxic activities against lung (H1299), breast (MCF-7) and prostate (PC-3) cancer cell lines and fibroblast (L929) cell lines of same extracts were determined under in vitro conditions. In addition, phenolic compunds, fatty acids and aroma components both truffle species were investigated qualitatively and quantitatively by using HPLC-DAD, GC-MS and SPME-GC-MS techniques, respectively. Also, characterization of polysaccharides of two truffle species and average molecular weights were determined by various techniques and methods. In addition to these the antioxidant activities of the polysaccharides obtained from truffle species in this thesis were investigated using 5 different methods. Extracts with high antioxidant activity were fractionated by column chromatography using adsorbents such as silica gel, sephadeks LH-20, and antioxidant activities of the fractions obtained were examined. From the most active fractions, seven compounds from R. westraliensis and four compounds from R. parvulosporus were purified by column chromatography, preparative thin layer chromatography and recycle HPLC system with various adsorbents and the chemical structures of isolated compounds were elucidated by spectroscopic methods such as (1D, 2D) NMR, FT-IR, EI-MS and ESI-MS techniques. The compounds obtained from R. westraliensis were Brassicastrol, Ergosta-7,9,22-trien-3β-ol, Ergosterol peroxide, Adenosine, D-Ribitol, Fumaric acid and Mannitol while compounds from R. parvulosporus were Brassicasterol, Ergosterol peroxide, Fumaric acid and Mannitol. The antioxidant, anticholinesterase, cytotoxic, anti-tyrosinase, anti-urease and anti-diabetic activities of purified compounds with sufficient amount were determined. According to this the adenosine isolated from R. westraliensis has higher DPPH and ABTS radical scavenging assays than the used standard, BHA. The ergosta-7,9,22-trien-3β-ol compound isolated from both truffles subject to the thesis had the highest cytotoxic activity against breast cancer (MCF-7) (IC50: 24.93±0.80 µg/mL) and lung cancer (IC50: 38.62±0.46 µg/mL) cell lines compared to other components that we isolated. In addition, brassicastrol (IC50: 5.85±0.16 µg/mL) and ergosterol peroxide (IC50: 6.98±0.24 µg/mL) compounds showed higher anti-urease activity than the standard thiourea. With this thesis, the bioassay guided isolation of pure compounds of R. parvulosporus and R. westraliensis truffle species was investigated for the first time. The detailed biological activities of the extracts and pure compounds obtained from these species, and fatty acid components, aroma components and phenolic profiles of these two truffle species were also determined for the first time in this thesis.