الفهرس 
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Abstract
Abstract
It is critical to investigate new antibiotic-free strategies to combat bacterial infections like “Klebsiella pneumoniae”. Originally ten bacterial isolates, four genera were recovered from human clinical samples (pus and deep pulmonary sputum) and identified with cultural, morphological, and biochemical characteristics, then by GNB card and VITEK 2 system. These isolates identified as Acintobacter baumannii, Klebsiella pneumoniae, Proteus mirabilis and pseudomonas aeruginosa. Three different plant materials (Capsicum Annum L., Solanum tuberosum L. peel, and Ammi Visnaga) were collected and extracted by different solvents. Their antibacterial activity was screened against the recovered bacterial genera. The Capsicum Annum showed a strong antibacterial activity against Klebsiella pneumoniae strain 3MAG with MIC of 12 mg/ml and MBC of 18 mg/ml. Total phenolic content of the ethanolic extract was equal to 8.4±0.9 mg/g. Capsaicin and its derivatives were determined by HPLC from ethanolic extracts of spicy green pepper. Capsaicin concentration measured 0.66 mg/g, and dihydrocapsaicin measured 0.48 mg/g but nor-dihydrocapsaicin measured 0.10 mg/g. While marine environments are considered an interesting source of new active ingredients. So, the fractionation and purification of the dibutyl phthalate ester compound were achieved using silica gel column G254 and preparative thin-layer chromatography (TLC). Spectrum data such as UV spectroscopy, liquid chromatography mass spectroscopy (LC-mass), and nuclear magnetic resonance (NMR) aided in the structure elucidation of dibutyl phthalate. A pure compound of dibutyl phthalate ester was extracted from a marine-derived fungus of Aspergillus sp. 3MAG isolated from soft coral collected from the Red Sea. The suppression of Klebsiella pneumoniae strain 3MAG by dibutyl phthalate ester was an intriguing finding in our investigation measured by MIC of value 40 µg/ml and MBC of value 200 µg/ml. The kinetic time killer curve showed that the bacterial cells die within 4 hours. The application of the transmission electron microscope technique detected Klebsiella pneumoniae strain 3MAG cellular damage after being exposed to dibutyl phthalate ester instead of its typical cell shape. An oxidative activity test of dibutyl phthalate at MIC with human DNA and protein demonstrated no significant changes in total soluble protein profiles using SDS-PAGE electrophoresis and no presumed cleavage for DNA bands using gel-electrophoresis. The ADME-related physicochemical properties of the obtained compound were predicted using Swiss-ADME web tools and the ProToxii webserver was used to estimate in silico toxicity.