scholarly journals Cr(III) and Ni(II) Complexes of Isatin-hydrazone Ligand: Preparation, Characterization, Dft Studies, Biological Activity, and Ion-Flotation Separation of Ni(II)

Author(s):  
Hany Youssef ◽  
Yasir Abdulhamed ◽  
Tarek Yousef ◽  
Gaber Abu El-Reash

Abstract In the current work, a ligand N'1-((E)-2-hydroxy-3H-indol-3-ylidene)-N'3-((E)-2-oxoindolin-3-ylidene)malonohydrazide (H4MDI) and its Cr(III) and Ni(II) complexes have been synthesized and characterized by various conventional methods. For evaluating the optimal ligand structure and its complexes, calculations of DFT were applied. Magnetic measurements inherent to their electronic spectra show that both Cr(III) and Ni(II) chelates have octahedron coordination frameworks. On the other hand, the IR spectral data revealed that the ligand behaves as a binegtive hexadentate in [Cr2(H2MDI)(H2O)2Cl4] and as a tetranegative hexadentate in [Ni2(MDI)(H2O)6].4H2O. In addition, the behavior of thermal decomposition for prepared complexes was discussed. Two comparable methods (Coats-Redfern and Horowitz-Metzger) were used to calculate the kinetic parameters of the resulted thermal decomposition stages. Furthermore, the ion-flotation process was used for the separation of Ni(II) from aqueous media via the prepared ligand as a chelating agent and oleic acid as a surfactant. Moreover, the antimicrobial behavior of the synthesized moieties was investigated against various bacterial and fungal strains. H4MDI has the most activity with minimum inhibitory concentration (MIC) of 0.78 µg/mL for both E. coli, and C. Albicans, while Ni(II) complex shows the activity against S. aureus, E. coli, and C. Albicans with MIC of 2.34, 4.68, and 1.17 µg/mL, respectively. Finally, the in-vitro cytotoxic activity of the prepared compounds against hepatocellular carcinoma human tumor cells (HePG-2) has been examined, and revealed that H4MDI and its Ni(II) complex show very strong activity against HePG-2 with IC50 of 9.7 and 7.7 µmol/L, respectively.

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Hassan M. Faidallah ◽  
Sherif A. F. Rostom ◽  
Khalid A. Khan

The synthesis of polysubstituted pyridines, in addition to some derived pyrido[2,3-d]pyrimidine ring systems supported with chemotherapeutically active functionalities, is described. They were evaluated for theirin vitrocytotoxic effects against three different human tumor cell lines (human colon carcinoma HT29, hepatocellular carcinoma Hep-G2, and Caucasian breast adenocarcinoma MCF7). Nine compounds displayed variable cytotoxic potential, among which alkylthio analogs33,34, and37emerged as the most active members, being almost twice as active as doxorubicin against the colon carcinoma HT29 cell line. In addition, the same three analogs showed a clear differential cytotoxic profile as they exhibited a marginal inhibitory effect on the growth of the normal nontransformed human foreskin fibroblast Hs27 cell line. Meanwhile, nineteen compounds were able to exhibit significant antibacterial activity against both Gram-positive and Gram-negative bacteria, together with moderate antifungal activities. The pyrido[2,3-d]pyrimidine-2(1H)-thione30together with its alkylthio derivatives33and34stemmed as the most active antimicrobial members being equipotent to ampicillin againstS. aureus,E. coli,andP. aeruginosa,together with a noticeable antifungal activity againstC. albicans.Compounds33and34could be considered as a promising template for possible dual antimicrobial-anticancer candidates.


2018 ◽  
Vol 106 (6) ◽  
pp. 465-476 ◽  
Author(s):  
Mamdoh R. Mahmoud ◽  
Sameh H. Othman

Abstract The present study evaluates the performance of ion flotation process for removal of uranyl tricarbonate complex, UO2(CO3)34−, which is the dominant species in many aqueous media particularly seawater, from aqueous solutions using cetyltrimethylammonium bromide, CTAB, as a cationic surfactant. Flotation of UO2(CO3)34− as a function in the solution pH is investigated in absence and in presence of carbonate. Removal percentage >99% is achieved in the pH range 8.5–11.5 in presence of 5×10−3 M carbonate. The influence of concentrations of ethanol (0.1–2% v/v) and CTAB (5×10−5–1.4×10−3 M) show that UO2(CO3)34− is efficiently removed at concentrations of 0.5–1.5% v/v and 4×10−4–1×10−3 M, respectively. Based on the obtained kinetic data, the flotation mechanism and the flotation rate are investigated using two different flotation models. Floatability of UO2(CO3)34− in presence of different cations (Ba2+, Ca2+, Mg2+ and Sr2+) and anions (NO3−, Br−, Cl−, SO42− and HPO42−) is studied. Except for Mg2+ and NO3−, the flotation efficiency of UO2(CO3)34− is significantly decreased at concentrations higher than 1×10−3 and 5×10−3 M of the studied cations and anions, respectively. Ion flotation process is efficiently applied for removal of uranium(VI), R%>98.5%, from seawater. Accordingly, ion flotation can be considered as a promising technique and thus its feasibility for removal and/or recovery of uranium(VI) from many aqueous environment.


2021 ◽  
Vol 14 (4) ◽  
pp. 370
Author(s):  
Le Phuong Nguyen ◽  
Chul Soon Park ◽  
Naina Adren Pinto ◽  
Hyunsook Lee ◽  
Hyun Soo Seo ◽  
...  

The siderophore–antibiotic conjugate LCB10-0200 (a.k.a. GT-1) has been developed to combat multidrug-resistant Gram-negative bacteria. In this study, the in vitro activity of LCB10-0200 and LCB10-0200/avibactam (AVI) has been investigated against carbapenem-resistant Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa. Minimal inhibitory concentrations (MICs) of LCB10-0200, LCB10-0200/AVI, aztreonam, aztreonam/AVI, ceftazidime, ceftazidime/AVI, and meropenem were measured using the agar dilution method. Whole genome sequencing was performed using Illumina and the resistome was analyzed. LCB10-0200 displayed stronger activity than the comparator drugs in meropenem-resistant E. coli and K. pneumoniae, and the addition of AVI enhanced the LCB10-0200 activity to MIC ≤ 0.12 mg/L for 90.5% of isolates. In contrast, whereas LCB10-0200 alone showed potent activity against meropenem-resistant A. baumannii and P. aeruginosa at MIC ≤ 4 mg/L for 84.3% of isolates, the combination with AVI did not improve its activity. LCB10-0200/AVI was active against CTX-M-, SHV-, CMY-, and KPC- producing E. coli and K. pneumoniae, while LCB10-0200 alone was active against ADC-, OXA-, and VIM- producing A. baumannii and P. aeruginosa. Both LCB10-0200 and LCB10-0200/AVI displayed low activity against IMP- and NDM- producing strains. LCB10-0200 alone exhibited strong activity against selected strains. The addition of AVI significantly increased LCB10-0200 activity against carbapenem-resistant E. coli, K. pneumoniae.


2020 ◽  
Author(s):  
Hans B. Smith ◽  
Tin Lok Li ◽  
Man Kit Liao ◽  
Grischa Y. Chen ◽  
Zhihong Guo ◽  
...  

ABSTRACTListeria monocytogenes is a Gram-positive intracellular pathogen that is highly adapted to invade and replicate in the cytosol of eukaryotic cells. Intermediate metabolites in the menaquinone biosynthesis pathway are essential for the cytosolic survival and virulence of L. monocytogenes, independent of the production of MK and aerobic respiration. Determining which specific intermediate metabolite(s) are essential for cytosolic survival and virulence has been hindered by the lack of an identified DHNA-CoA thioesterase essential for converting DHNA-CoA to DHNA in the MK synthesis pathway. Using the recently identified Escherichia coli DHNA-CoA thioesterase as a query, homology sequence analysis revealed a single homolog in L. monocytogenes, LMRG_02730. Genetic deletion of LMRG_02730 resulted in an ablated membrane potential, indicative of a non-functional electron transport chain (ETC) and an inability to aerobically respire. Biochemical kinetic analysis of LMRG_02730 revealed strong activity towards DHNA-CoA, similar to its E. coli homolog, further demonstrating that LMRG_02730 is a DHNA-CoA thioesterase. Functional analyses in vitro, ex vivo, and in vivo using mutants directly downstream and upstream of LMRG_02730 revealed that DHNA-CoA is sufficient to facilitate in vitro growth in minimal media, intracellular replication, and plaque formation in fibroblasts. In contrast, protection against bacteriolysis in the cytosol of macrophages and tissue specific virulence in vivo requires the production of DHNA. Taken together, these data implicate LMRG_02730 (renamed MenI) as a DHNA-CoA thioesterase and suggest that while DHNA protects the bacteria from killing in the macrophage cytosol, DHNA-CoA is necessary for intracellular bacterial replication.


Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.


2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.


Author(s):  
Павел Алексеевич Какорин ◽  
Татьяна Владимировна Фатеева ◽  
Ольга Ивановна Терешкина ◽  
Ирина Борисовна Перова ◽  
Галина Владиславовна Раменская ◽  
...  
Keyword(s):  

На основании ранее проведенных исследований установлен профиль флавоноидов лиофилизированного водного извлечения, полученного из побегов C. jubata. В связи с тем, что, согласно данным литературы, флавоноиды являются потенциальными ингибиторами микроорганизмов, проведено изучение антимикробной активности лиофилизата в опытах in vitro с использованием скринигового метода определения антимикробной активности для препаратов растительного происхождения. При изучении бактериостатической и фунгистатической активности в опытах in vitro использовали метод двукратного серийного разведения препаратов в жидких питательных средах. В результате исследования лиофилизированного водного извлечения караганы гривастой установлено наличие умеренной антимикробной активности в отношении всех изученных штаммов патогенных микроорганизмов: грамположительных и грамотрицательных бактерий (S. aureus, E. coli, P. vulgaris, P. aeruginosa), дрожжеподобных и мицелиальных грибов (C. albicans, M. canis). Полученные данные позволяют рекомендовать лиофилизированное водное извлечение караганы гривастой для создания на его основе лекарственных форм наружного применения для лечения заболеваний кожи и слизистых оболочек, связанных с бактериальным воспалительным процессом.


Author(s):  
Е. Ю. Тризна ◽  
Д. Р. Байдамшина ◽  
Александр А. Виницкий ◽  
А. Р. Каюмов
Keyword(s):  

Исследована способность лиофилизата бовгиалуронидазы азоксимера («Лонгидаза») разрушать бактериальные биопленки S. aureus, E. faecalis, E. coli, а также сочетанное действие препарата с антибактериальными средствами. Показано, что 2 ч инкубации бовгиалуронидазы азоксимер в концентрации 750 – 1500 МЕ/мл вызывает двукратное снижение биомассы матрикса зрелых биопленок E. faecalis и E. coli, и на 60 % — S. aureus. Данный ферментный препарат не влияет на образование бактериальных биопленок. При сочетанном применении с антибактериальными средствами препарат повышает их эффективность в отношении бактерий в составе биопленок. Так, концентрация ципро-флоксацина и амоксициллина, необходимая для снижения количества КОЕ на 3 порядка в биопленке E. faecalis, в присутствии бовгиалуронидазы азоксимера снижается в 16 раз (p < 0,05). В присутствии фермента в 16 раз меньшие концентрации цефуроксима, фосфомицина, ципрофлоксацина и амикацина достаточны для снижения количества КОЕ на 3 порядка в биопленке E. coli (p < 0,05), и в значительно меньшей концентрации цефуроксим оказывает бактерицидное действие на клетки в биопленке S. aureus (p < 0,05). Вероятно, бовгиалуронидаза азоксимер увеличивает проникновение антибактериальных средств к клеткам бактерий в биопленке, что обеспечивает потенцирование их антибактериального эффекта. Такое действие ферментного препарата позволяет снизить дозу и повысить безопасность антибактериальных средств при сохранении их эффективности.


2019 ◽  
Vol 65 (5) ◽  
pp. 760-765
Author(s):  
Margarita Tyndyk ◽  
Irina Popovich ◽  
A. Malek ◽  
R. Samsonov ◽  
N. Germanov ◽  
...  

The paper presents the results of the research on the antitumor activity of a new drug - atomic clusters of silver (ACS), the colloidal solution of nanostructured silver bisilicate Ag6Si2O7 with particles size of 1-2 nm in deionized water. In vitro studies to evaluate the effect of various ACS concentrations in human tumor cells cultures (breast cancer, colon carcinoma and prostate cancer) were conducted. The highest antitumor activity of ACS was observed in dilutions from 2.7 mg/l to 5.1 mg/l, resulting in the death of tumor cells in all studied cell cultures. In vivo experiments on transplanted Ehrlich carcinoma model in mice consuming 0.75 mg/kg ACS with drinking water revealed significant inhibition of tumor growth since the 14th day of experiment (maximally by 52% on the 28th day, p < 0.05) in comparison with control. Subcutaneous injections of 2.5 mg/kg ACS inhibited Ehrlich's tumor growth on the 7th and 10th days of the experiment (p < 0.05) as compared to control.


2019 ◽  
Vol 35 (6) ◽  
pp. 91-101
Author(s):  
F.A. Klebanov ◽  
S.E. Cheperegin ◽  
D.G. Kozlov

Mutant variants of mini-intein PRP8 from Penicillium chrysogenum (Int4b) with improved control of C-terminal processing were characterized. The presented variants can serve as a basis for self-removed polypeptide tags capable of carrying an affine label and allowing to optimize the process of obtaining target proteins and peptides in E. coli cells. They allow to synthesize target molecules in the composition of soluble and insoluble hybrid proteins (fusions), provide their afnne purification, autocatalytic processing and obtaining mature target products. The presented variants have a number of features in comparison with the known prototypes. In particular the mutant mini-intein Int4bPRO, containing the L93P mutation, has temperature-dependent properties. At cultivation temperature below 30 °C it allows the production of target molecules as part of soluble fusions, but after increasing of cultivation temperature to 37 °C it directs the most of synthesized fusions into insoluble intracellular aggregates. The transition of Int4bPRO into insoluble form is accompanied by complete inactivation of C-terminal processing. Further application of standard protein denaturation-renaturation procedures enable efficiently reactivate Int4bPRO and to carry out processing of its fusions in vitro. Two other variants, Int4b56 and Int4b36, containing a point mutation T62N or combination of mutations D144N and L146T respectively, have a reduced rate of C-terminal processing. Their use in E. coli cells allows to optimize the biosynthesis of biologically active target proteins and peptides in the composition of soluble fusions, suitable for afnne purification and subsequent intein-dependent processing without the use of protein denaturation-renaturation procedures. intein, fusion, processing, processing rate, gelonin The work was supported within the framework of the State Assignment no. 595-00003-19 PR.


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