摘要
设计并合成了两个新的氟代香豆素化合物8-(3-氟苯甲酰基)-7-羟基-4-甲基香豆素(3a)和8-(4-氟苯甲酰基)-7-羟基-4-甲基香豆素(3b),其结构通过元素分析、IR和1HNMR进行了表征,通过X-射线单晶衍射测定了化合物3b的晶体结构,单晶结构分析表明,化合物3b的晶体属于单斜晶系.体外抑菌试验结果显示,目标化合物对大肠杆菌(E.coli)、枯草杆菌(B.subtilis)和金色葡萄球菌(S.aureus)有不同程度的抑制作用;体外抗氧化实验显示,目标化合物对超氧阴离子自由基(O2-·)和二苯代苦味肼基自由基(DPPH·)均有良好的清除能力;运用荧光光谱法研究了不同温度下目标化合物与牛血清白蛋白(BSA)的相互作用,结果表明,目标化合物对BSA的荧光猝灭均属于静态猝灭,相关热力学参数表明,化合物3a(H<0,S<0,G<0)与BSA二者之间主要以氢键或范德华力相结合,化合物3b(H>0,S>0,G<0)与BSA二者之间主要靠疏水作用力相结合;依据Fster's非辐射能量转移理论,求得BSA与化合物3a和化合物3b间的距离(r)分别为2.53和2.65nm,说明两个化合物与BSA之间可能发生了非辐射能量转移.
Two novel coumarin derivatives,8-（3-fluorobenzoyl）-7-hydroxy-4-methylcoumarin （3a） and 8-（4fluorobenzoyl）-7-hydroxy-4-methylcoumarin （3b）,were synthesized by Fries rearrangement.Their structures were identified by IR,1H NMR and elemental analysis,and the crystal structure of compound 3b was determined by single crystal X-ray diffraction.The crystal of compound 3b belongs to monoclinic system.Their antibacterial activities were evaluated by the method of Oxford Cup,and the results indicated that the target compounds possess the activity for the inhibiting growth of E.coli,B.subtilis and S.aureus.Their antioxidation capacities were investigated by the superoxide anion （O2-·） and DPPH· scavenging methods,and the results showed that the title compounds have good radical-scavenging capacities.The interactions of the title compounds with bovine serum albumin （BSA） were investigated by fluorescence spectroscopy at different temperatures,the results indicated that the title compounds cause the fluorescence quenching of BSA through a static quenching procedure.The binding constants （Ka ） and the number of binding sites （n） between the title compounds and BSA were calculated by applying the double logarithmic curve equation at different temperatures,and the corresponding thermodynamic parameters enthalpy change （△H）,entropy change （△S）,Gibbs free energy change （△G）,between the title compounds and BSA were also obtained according to the van’t Hoff equation.The interaction between the compound 3a （△H 0,△S 0,△G 0） and BSA is driven mainly by hydrogen bond force or van der Waals force,whereas the interaction between the compound 3b （△H 0,△S 0,△G 0） and BSA is driven mainly by hydrophobic force.The binding average distance r between the donor （BSA） and acceptor （compound 3a and 3b） were obtained to be respectively 2.53 nm and 2.65 nm based on the Foster’s theory,which indicated the energy transfer could occur from BSA to the title compounds with
出处
《中国科学：化学》
CAS
CSCD
北大核心
2013年第7期858-868,共11页
SCIENTIA SINICA Chimica
基金
国家自然科学基金(30901815)资助
