oa Antibacterial, antitumor and antioxidant of bioactive compounds extracted from secondary metabolites of the fungus Rhizoctonia solani Kuhn

Abstract The aim of this study is to examine the bioactive compounds from secondary metabolites of the fungus Rhizoctonia solani against some selected strains of pathogenic bacteria. The fungus grown in a fermented culture and the filtrate was extracted in different chemical solvents. The fungal crude extract was used to examine the bioactivity against six strains of bacteria using disc diffusion method. The results showed that the fungal extract exhibited highest growth inhibition against E. coli (34 mm inhibition zone) and S. aureus (38 mm). The minimal inhibitory concentration (MIC) values were 12.5 ug/ml and 6.5 ug/ml against E. coli and S. aureus, respectively. The fungal crude extract did not show any toxicity against human red blood. A comparison between bioactivity of the fungal extract with five commercial drugs against the tested bacteria showed that the fungal extract exhibited a significant bacterial growth inhibition than the commercial drugs. Meantime, the fungal extract showed an antitumor bioactivity by using tumor cell-line of Hep2 at low concentration (0.05 mg/ml). Also the fungal extract revealed an antioxidant action by using Fe II reduction test. Chemical analysis by using FT-IR, HNMR, and GC-Mass techniques indicated that the fungal extract composed of two main chemical compounds; Malonic acid, 2, 4-dimethyl-3-yl ethyl ester with a chemical formula C12H22O4 and Molecular weight of 230 kd and Pentanedioic,2-oxo-dimethyl ester with a chemical formula C7H10O5 and molecular weight of 174 kd. It can be concluded that the fungus R. solani possesses a potential bioactive compounds as a promising agents in medical therapy.