17-18 May 2022
Online
Asia/Tehran timezone
شرکت‌کنندگان گرامی، علیرغم تعطیلی اضطراری تهران در روز سه‌شنبه ٢٧ اردیبهشت، دوازدهمین همایش کاربران چشمه نور ایران مطابق با برنامه‌ی از پیش اعلام شده، کماکان به شکل مجازی برگزار خواهد شد.

دفتر آموزش و توسعه کاربران چشمه نور ایران

Data Analysis Procedure of Synchrotron-Based X-Ray Absorption Spectroscopy

May 18, 2022, 2:00 PM
20m
Online

Online

in Persian

Speaker

Dr Abdolhamed Shahedi (Kerman Graduate University of Advanced Technology)

Description

An original complex with europium on the basis of diazafluoren, such that dafone is 4,5- diazaf1uoren-9-one is fabricated and characterized using Extended X-ray Absorption Fine Structure (EXAFS), IR spectroscopy, UV-Vis spectroscopy and elemental analysis. Since the europium complex structure is not achievable via typical crystallographic approaches, an XAFS spectrum was acquired for LIII Eu crystal edge at 6977 eV energy. EXAFS for structural recognition, the complex Eu(dafone)zCl2.(H2O)2(H2O) was assessed. Both of the ligands were completely coordinated in regard to the metal with four nitrogen sites for Eu(dafone)zClz.(H2O)2(H2O). Close-neighbor correlations from nitrogen atoms on macrocycli cages are evident within the spectra as well as to the adjoining carbon backbones. Debye-Waller factors and Bond distances are also reported. For the purpose of exploring the links between the biological and structural characteristics, in vitro antibacterial characteristics and DNA/BSA binding propensity were also evaluated. The DNA complex interaction mode was evaluated using electronic absorption titration, circular dichroism spectroscopy, viscometric assessment, thermodynamic studies, impact of ionic strength, competitive binding experiment, and luminescence titration. The outcomes show that the complex binds to FS-DNA at adequate intercalation ability with planar dafone ligand partial insertion among the double-stranded DNA base stacks via binding constant (Kb) of 2.4 x 10⁵ M ’. The DNA viscosities and CD spectra present significant evidence of intercalation. Also, this complex interacts with bovine serum (BSA) albumin proteins have been studied by fluorescence spectroscopy technique and the obtained results reveal an excellent binding propensity in this case. A Eu (III) complex in vitro antibacterial efficacy on a set of Gram-negative bacteria and Gram-positive bacteria show that the complex displays marked antibacterial behavior. The minimum complex inhibitory concentrations show that it displays significantly higher antibacterial impact on conventional Staphylococcus aureus and Escherichia coli bacterial strains compared to those of silver sulfadiazine and europium nitrate. The Eu (III), bacterial inhibitions are closely linked to relevant DNA binding affinities.

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