(I)Probing long range electron transfer in ruthenium modified proteins and evaluating the SDS concentration by using electronically excited molecules(II) Essential oils from Taiwan: chemical composition and antibacterial activity against Escherichia coli

• Main Authors: Lin, Po-Chen, 林柏成
• Other Authors: Chang, I-Jy
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/73162849695285154029

博士 === 國立臺灣師範大學 === 化學系 === 105 === Ruthenium bipyridine-type compounds, [Ru((CH3)2bpy)2(im)2]2+ and [Ru((COO−)2bpy)2(im)2]2−, were synthesized to evaluate the protein electron transfer property by flash-quench method. After reacting with Ru(NH3)63+, [Ru((CH3)2bpy)2(im)2]2+, with electron donating substitutents, gives quenching yield of 25.1% and formation yield of [RuIII( )2(im)2]3+ species of 42.0%. While [Ru((COO−)2bpy)2(im)2]2−, with electron withdrawing substitutents, has 65.2% of quenching yield and 19.6% of formation yield of [RuIII( )2(im)2]3+ species. In those ruthenium modified cytochrome c, Ru((CH3)2bpy)2(im)(His33)-Fe2+-cyt c has the largest quantum yield of intramolecular electron transfer (17.6%) and the smallest for Ru((COO−)2bpy)2(im)(His33)-Fe2+-cyt c (11.9%). Although driving force favors for Ru((COO−)2bpy)2(im)(His33)-Fe2+-cyt c, cage effect and chemical reaction are other variable factors in the trend. Ru(bpy)2dppz2+, known for its light switch property, had been utilized to evaluate the concentration of SDS. As the concentration of SDS increases, the emission intensity of Ru(bpy)2dppz2+ increases. Unfortunately, at the attempt to lower the SDS concentration below 0.1%, Ru(bpy)2dppz2+ precipitates, therefore, ethidium bromide (EtdBr) was employed. In the low concentration of SDS (0−0.1%), the wavelength of absorption maximum red shifts and the emission intensity decreases. While the concentration of SDS is above 0.1%, the wavelength of absorption maximum blue shifts and the emission intensity is recovering. At above the CMC of SDS, the emission intensity remains unchanged and is higher than that without SDS. An assay for evaluating of SDS concentration by EtdBr has been proposed. Chemical compositions of seven essential oils from Taiwan had been analyzed by gas chromatography−mass spectroscopy. The eluates had been identified by matching the mass fragment patents to the NIST 08 database. Quantitatively analysis showed the major components are somewhat different from the same essential oils reported that are obtained from other origins. The antibacterial activity of the essential oils against Escherichia coli was evaluated by optical density method. Patchouli is a very effective inhibitor that completely inhibits the growth of E. coli at 0.05%. Clove basil and sweet marjoram are good inhibitors and their upper limits of minimum inhibitory concentration are 0.1%.