The binary systems of RE3+ with the newly synthesized fluorescent reagent H2L[5(2'-carboxybenzenazo) rhodanine] (RACP), 5-(4'-chloro-2'-carboxybenzenazo) rhodanine (Cl- RACP) and 5-(4'-bromo-2'-car...The binary systems of RE3+ with the newly synthesized fluorescent reagent H2L[5(2'-carboxybenzenazo) rhodanine] (RACP), 5-(4'-chloro-2'-carboxybenzenazo) rhodanine (Cl- RACP) and 5-(4'-bromo-2'-carboxybenzenazo) rhodanine (Br-RACP) in 70% ethanol aqueous solutions have been studied by potentiometric titration. The formation constants and distribution of various species al different pH have been determined. The apparent dissociation constants of H2L decrease on the following sequence:RACP>Cl-RACP>Br-RACP, but the cumulative formation constants of the complexes with Nd3+ remain constant. Further investigation on the binary systems of 15 RE elements with RACP. 1gβ110 and 1gβ120 values shows 'tetrad effect', and no complex in the form of ML3 exists in the systems.展开更多
Bacterial infections present a serious challenge to healthcare practitioners due to the emergence of resistance to numerous conventional antibacterial drugs. Therefore, new bacterial targets and new antimicrobials are...Bacterial infections present a serious challenge to healthcare practitioners due to the emergence of resistance to numerous conventional antibacterial drugs. Therefore, new bacterial targets and new antimicrobials are unmet medical needs. Rhodanine derivatives are known to possess potent antimicrobial activities. In this study, we determined the activity spectrum of a series of new rhodanine derivatives against representative Gram-positive and Gram-negative bacterial strains. Compounds 3a and 5a had the highest activity with minimum inhibitory concentrations in the range of 1.12 - 2.5 μg/mL. Transmission electron microscope results confirmed that activities against bacteria occurred via rupturing of the cell wall. Molecular modeling results suggested that rhodanine derivatives have the potential to irreversibly bind to the penicillin-binding protein (PBP) Ser62 residue in the active site. Thus, our results suggested that these rhodanine derivatives could be potential antibacterial drug candidates with strong activity against Gram-negative bacteria.展开更多
This theoretical chemical reactivity study was conducted using the Density Functional Theory (DFT) method, at computational level B3LYP/6-31G (d). It involved a series of six (06) 5-arylidene rhodanines and allowed to...This theoretical chemical reactivity study was conducted using the Density Functional Theory (DFT) method, at computational level B3LYP/6-31G (d). It involved a series of six (06) 5-arylidene rhodanines and allowed to predict the chemical reactivity of these compounds. DFT global chemical reactivity descriptors (HOMO and LUMO energies, chemical hardness, softness, electronegativity) were examined to predict the relative stability and reactivity of rhodanin derivatives. Thus, the compound 6 which has an energy gap between the orbitals of ΔEgap = 3.004 eV is the most polarizable, the most reactive, the least stable, the best electron donor and the softest molecule. Calculation of the local indices of reactivity as well as dual descriptors revealed that the sulfur heteroatom of the Rhodanine ring is the privileged site of electrophilic attack in a state of sp3 hybridization and privileged site of nucleophilic attack in a state of sp2 hybridization.展开更多
A facile preparation of ZnO nanobelts by chemical precipitation technique and its utility as catalyst in Knoevenagel condensation of 2,4-thiazolidinedione/rhodanine has been described. X-ray diffraction and transmissi...A facile preparation of ZnO nanobelts by chemical precipitation technique and its utility as catalyst in Knoevenagel condensation of 2,4-thiazolidinedione/rhodanine has been described. X-ray diffraction and transmission electron microscopy techniques revealed the formation ZnO nanobelts. Scanning electron microscopic observations indicate that the lengths of nanobelts are ranging from a few hundreds of micrometers to a few millimeters. Its use for the condensation of aldehydes and active methylene compounds under solvent free reaction condition at 90℃ afforded the corresponding products in excellent yields in minute time.展开更多
The 3VHE protein is considered as a potential target for the treatment of prostate cancer. In order to find new 3VHE inhibitors, pharmacophore models based on the molecular structure of rhodanine derivatives and a thr...The 3VHE protein is considered as a potential target for the treatment of prostate cancer. In order to find new 3VHE inhibitors, pharmacophore models based on the molecular structure of rhodanine derivatives and a three-dimensional quantitative structure-activity relationship model (3D-QSAR) have been developed and validated by different methods. The 3D-QSAR model was evaluated for its predictive performance on a diverse test set containing 18 prostate cancer inhibitors. It presents very interesting internal and external statistical validation parameters (SD = 0.081;R2 = 0.903;Q2 = 0.869;;F = 247.2). This result suggests that the 3D-QSAR combinatorial model can be used to search for new 3VHE inhibitors and predict their potential activity. Based on the combinatorial pharmacophore model, a virtual screening of the Enamine database was performed. Compounds selected after virtual screening were subjected to molecular docking protocols (HTVS, SP, XP and IFD). Twenty new active compounds have been identified and their absorption, distribution, metabolism and excretion (ADME) property calculated using Schr?dinger’s Qikprop module. These results suggest that these new compounds could constitute new chemical starting points for further structural optimization of 3VHE inhibitors.展开更多
文摘The binary systems of RE3+ with the newly synthesized fluorescent reagent H2L[5(2'-carboxybenzenazo) rhodanine] (RACP), 5-(4'-chloro-2'-carboxybenzenazo) rhodanine (Cl- RACP) and 5-(4'-bromo-2'-carboxybenzenazo) rhodanine (Br-RACP) in 70% ethanol aqueous solutions have been studied by potentiometric titration. The formation constants and distribution of various species al different pH have been determined. The apparent dissociation constants of H2L decrease on the following sequence:RACP>Cl-RACP>Br-RACP, but the cumulative formation constants of the complexes with Nd3+ remain constant. Further investigation on the binary systems of 15 RE elements with RACP. 1gβ110 and 1gβ120 values shows 'tetrad effect', and no complex in the form of ML3 exists in the systems.
文摘Bacterial infections present a serious challenge to healthcare practitioners due to the emergence of resistance to numerous conventional antibacterial drugs. Therefore, new bacterial targets and new antimicrobials are unmet medical needs. Rhodanine derivatives are known to possess potent antimicrobial activities. In this study, we determined the activity spectrum of a series of new rhodanine derivatives against representative Gram-positive and Gram-negative bacterial strains. Compounds 3a and 5a had the highest activity with minimum inhibitory concentrations in the range of 1.12 - 2.5 μg/mL. Transmission electron microscope results confirmed that activities against bacteria occurred via rupturing of the cell wall. Molecular modeling results suggested that rhodanine derivatives have the potential to irreversibly bind to the penicillin-binding protein (PBP) Ser62 residue in the active site. Thus, our results suggested that these rhodanine derivatives could be potential antibacterial drug candidates with strong activity against Gram-negative bacteria.
文摘This theoretical chemical reactivity study was conducted using the Density Functional Theory (DFT) method, at computational level B3LYP/6-31G (d). It involved a series of six (06) 5-arylidene rhodanines and allowed to predict the chemical reactivity of these compounds. DFT global chemical reactivity descriptors (HOMO and LUMO energies, chemical hardness, softness, electronegativity) were examined to predict the relative stability and reactivity of rhodanin derivatives. Thus, the compound 6 which has an energy gap between the orbitals of ΔEgap = 3.004 eV is the most polarizable, the most reactive, the least stable, the best electron donor and the softest molecule. Calculation of the local indices of reactivity as well as dual descriptors revealed that the sulfur heteroatom of the Rhodanine ring is the privileged site of electrophilic attack in a state of sp3 hybridization and privileged site of nucleophilic attack in a state of sp2 hybridization.
文摘A facile preparation of ZnO nanobelts by chemical precipitation technique and its utility as catalyst in Knoevenagel condensation of 2,4-thiazolidinedione/rhodanine has been described. X-ray diffraction and transmission electron microscopy techniques revealed the formation ZnO nanobelts. Scanning electron microscopic observations indicate that the lengths of nanobelts are ranging from a few hundreds of micrometers to a few millimeters. Its use for the condensation of aldehydes and active methylene compounds under solvent free reaction condition at 90℃ afforded the corresponding products in excellent yields in minute time.
文摘The 3VHE protein is considered as a potential target for the treatment of prostate cancer. In order to find new 3VHE inhibitors, pharmacophore models based on the molecular structure of rhodanine derivatives and a three-dimensional quantitative structure-activity relationship model (3D-QSAR) have been developed and validated by different methods. The 3D-QSAR model was evaluated for its predictive performance on a diverse test set containing 18 prostate cancer inhibitors. It presents very interesting internal and external statistical validation parameters (SD = 0.081;R2 = 0.903;Q2 = 0.869;;F = 247.2). This result suggests that the 3D-QSAR combinatorial model can be used to search for new 3VHE inhibitors and predict their potential activity. Based on the combinatorial pharmacophore model, a virtual screening of the Enamine database was performed. Compounds selected after virtual screening were subjected to molecular docking protocols (HTVS, SP, XP and IFD). Twenty new active compounds have been identified and their absorption, distribution, metabolism and excretion (ADME) property calculated using Schr?dinger’s Qikprop module. These results suggest that these new compounds could constitute new chemical starting points for further structural optimization of 3VHE inhibitors.
