Kamel A. Saleh

Di- and Tri-valent Metal Ions Interactions with Four Biodegradable Hydroxamate and Cataecholate Siderophores: New Insights into Their Complexation Equilibria

The interaction of a number of divalent and trivalent metal ions [iron(III), chromium(III) copper(II), cobalt(II) and nickel(II)] with four isolated and purified microbial catecholate and hydroxamate siderophores was studied using the pH-potentiometric technique to investigate the complexation behavior of these systems as these systems could mimic many biological interactions of the siderophore chelating agent. The protonation constants of these new siderophore analogues as well their binary complex species stability constants were determined using the Hyperquad 2008 estimation model program. From the determined stability constants of the metal complex species, the concentration distribution of the various metal ion complex species involving isolated siderophore analogues in solutions was estimated using the HySS 2009 modeling program. The complex species distribution diagrams were plotted and discussed. Additionally, the Gibbs energies and the molecular structures of the formed complex species were evaluated and predicted using Gaussian 09 software for molecular modeling and density functional theory calculations.

Microbial production of four biodegradable siderophores under submerged fermentation

Four siderophore analogues were isolated and purified from Escherichia coli, Bacillus spp. ST13, and Streptomyces pilosus microorganisms under some specific submerged fermentation conditions. In order to evaluate the highest production of this siderophore analogues through the growth, a rapid spectrophotometric screening semi-quantitative method was used, in which interestingly the analogues were isolated in its own form not its iron chelate. After chromatographic separation, the chemical structures of the isolated and purified siderophores were illustrated using detailed spectroscopic techniques. The biodegradation studies were done on that four novel isolated and purified siderophores following OECD protocols. In addition, the bioactivities of these siderophores and their iron complexes were examined and evaluated.

Bioactivities of Novel Metal Complexes Involving B Vitamins and Glycine

Abstract In this work twelve novel mixed ligand complexes were synthesized. The complexes were formed between a metal ion (Cu(II), Cd(II), Mn(II), Fe(III), Ni(II), Pb(II)) and vitamins (B 3 and B 9) as primary ligands, and glycine as secondary ligand. Melting points, conductivities, and magnetic susceptibilities of the synthesized complexes were determined and the complexes were subjected to elemental analyses. The presence of coordination water molecules in the complex was also supported by TG/DTG thermal analysis. Full elucidation of the molecular structures for the synthesized mixed ligand complexes were confirmed using detailed spectroscopic IR, 1H-, 13C-NMR, and XRD techniques. In addition, cytotoxic and antioxidant activities of the twelve synthesized solid complexes were tested to evaluate their bioactivities.

Platinum and vanadate Bioactive Complexes of Glycoside Naringin and Phenolates

Abstract Platinum(II) and vanadium(V) solid binary and ternary complexes involving naringin, a flavanone glycoside in found in grapefruit, and some phenolic acids were synthesized and fully characterized using detailed structural and spectroscopic analysis techniques such as IR, NMR, and SEM techniques. The magnetic susceptibility results as well line drawings of the platinum and vanadium complexes showed four-coordinate square-planar and remarkable low-spin diamagnetic species; which is in agreement with the structures proposed. The cytotoxic activities of the binary and ternary vanadium and platinum metal complexes of phenolic acids and naringin were tested and evaluated against HepG2 (human hepatocellular carcinoma), MCF-7 (human breast adenocarcinoma), and HCT116 (human colorectal carcinoma) tumor cell lines. Also, their antioxidant activities were examined by free radical scavenging assay. The relationship between the chemical structure of the synthesized complexes and their biological influence was studied and evaluated.

Simulative aurintricarboxylic acid molecular docking with antitumor activity for its VO(II), Cr(III), Mn(II) and Fe(III) complexes, HF/DFT modeling and elaborated EPR studies

A synthesized aurintricarboxylic acid (ATA) complex was deliberately investigated. Spectral, thermal, theoretical and antitumor studies are accomplished in this study. Elaborated electronic and EPR considerations are introducing parameters support the structural discussion of complexes. Octahedral geometry is proposed for all complexes except VO(II) is a square-pyramidal configuration. Molecular modeling utilizing Gaussian 09 program (HF/DFT) was used to verify the mode of bonding through the optimized geometries as well as essential quantum parameters were calculated using frontier energies (EHOMO & ELUMO). The soft character of the complexes may expect their excellent biological feature. The molecular docking computational achievement displays distinguished bounds of ATA drug with human colorectal carcinoma and human hepatic carcinoma. However, the interaction with human breast carcinoma receptor is completely absent. This behavior may clarify the antitumor activity of the complexes under investigation. The experimental work was supported with docking for carcinoma receptors used experimentally. VO(II) complex displays distinguished inhibition activity toward human carcinoma used. This is pointed to the other important use for ATA drug complexes exceeding the antibacterial field.

Lack of micronuclei formation in bone marrow of rats after oral exposure to thiocyclam insecticide

In this study, a nereistoxin analogue insecticide, thiocyclam, was administered to adult male albino rats by gavage dose of 135, 270 and 540 mg/kg b.w. repeated for 5 days at 24 h intervals. Control animals received only water. Thiocyclam was tested for its potential to cause genotoxic effects in rat bone marrow cells using an in vivo micronucleus assay. After 24 h of the last treatment, rats from all dose levels were sacrificed. Bone marrow cells were collected and assayed for the presence of micronuclei. Thiocyclam did not cause any increase in the incidence of micronucleated polychromatic erythrocytes in rats bone marrow at any of the dose levels. The polychromatic erythrocytes/normochromatic erythrocytes (PCE:NCE) ratio was found to be in the range from 0.50 ± 0.11 to 0.55 ± 0.02. The results of this study demonstrate that the effect of thiocyclam is not significant in the rat in vivo micronucleus assay.

Cell Cycle Arrest in Different Cancer Cell Lines “Liver, Breast, and Colon” Induce Apoptosis under the Influence of the Chemical Content of Aeluropus lagopoides Leaves Extracts

Natural product especially secondary metabolites that produced by plants under the stressed condition shown to have a different pharmacological impact. Aeluropus lagopoides is one of the typical halophyte plants survivals under stressed conditions. It has been used for wound healing and as a painkiller. The bioactivity and the chemical composition of this plant have poorly investigated. Consequently, chemical components of A. lagopoides leaves were extracted using hexane (nonpolar), ethyl acetate (semi-polar), n-butanol (polar) to extract the most extensive variety of metabolites. The cytotoxicity and anticancer impact of extracted secondary metabolites evaluated against breast (MCF-7), colon (HCT-116), and liver (HepG2) cancer cell lines using SRB test. The mechanism of action verified by observing the appearance of apoptotic bodies using the fluorescent microscope while their antiproliferative impact had been evaluated using flow cytometer. Results revealed that secondary metabolites extracted using hexane and ethyl acetate were having the highest cytotoxicity and thus anticancer activity effect on HepG2 with IC50 (24.29 ± 0.85, 11.22 ± 0.679 μg/mL) respectively. Where apoptotic bodies observed, flow cytometer results exhibited that secondary metabolites can inhibit cell cycle in G0/G1 phase. Accordingly, A. lagopoides hexane and ethyl acetate extracts may consider as a candidate anti-cancer drug.

Anti-angiogenic activity of Middle East medicinal plants of the Lamiaceae family

Angiogenesis plays a crucial role in malignant tumor progression and development. The present study aimed to identify lead plants with selective anti-angiogenic properties. A total of 26 methanolic extracts obtained from 18 plants growing in Saudi Arabia and Jordan that belong to the Lamiaceae family were screened for their cytotoxic and anti-angiogenic activities using MTT and rat aortic ring assays, respectively. Four novel extracts of Thymbra capitata (L.) Cav., Phlomis viscosa Poir, Salvia samuelssonii Rech.f., and Premna resinosa (Hochst.) Schauer were identified for their selective anti-angiogenic effects. These extracts did not exhibit cytotoxic effects on human endothelial cells (EA.hy926) indicating the involvement of indirect anti-angiogenic mechanisms. The active extracts are potential candidates for further phytochemical and mechanistic studies.

Synthesis of Novel VO(II)-Perimidine Complexes: Spectral, Computational, and Antitumor Studies

A series of perimidine derivatives (L1–5) were prepared and characterized by IR, 1H·NMR, mass spectroscopy, UV-Vis, XRD, thermal, and SEM analysis. Five VO(II) complexes were synthesized and investigated by most previous tools besides the theoretical usage. A neutral tetradentate mode of bonding is the general approach for all binding ligands towards bi-vanadyl atoms. A square-pyramidal is the configuration proposed for all complexes. XRD analysis introduces the nanocrystalline nature of the ligand while the amorphous appearance of its metal ion complexes. The rocky shape is the observable surface morphology from SEM images. Thermal analysis verifies the presence of water of crystallization with all coordination spheres. The optimization process was accomplished using the Gaussian 09 software by different methods. The most stable configurations were extracted and displayed. Essential parameters were computed based on frontier energy gaps with all compounds. QSAR parameters were also obtained to give another side of view about the biological approach with the priority of the L3 ligand. Applying AutoDockTools 4.2 program over all perimidine derivatives introduces efficiency against 4c3p protein of breast cancer. Antitumor activity was screened for all compounds by a comparative view over breast, colon, and liver carcinoma cell lines. IC50 values represent promising efficiency of the L4-VO(II) complex against breast, colon, and liver carcinoma cell lines. The binding efficiency of ligands towards CT-DNA was tested. Binding constant (K b) values are in agreement with the electron-drawing character of the p-substituent which offers high K b values. Also, variable Hammetts relations were drawn.

Bioactive Lignans: A Survey Report on their Chemical Structures?

Lignans are polyphenols spread in a wide variety of plant-based foods, including seeds, whole grains, legumes, fruit, and vegetables. When consumed, lignan precursors are converted to the enterolignans, enterodiol and enterolactone, by bacteria that normally colonize the human intestine. Lignans have attracted considerable attention due to their pharmacological and biological activities. This review article is a survey on the molecular structure of about 276 new naturally occurring lignans obtained from different plant families. We classified seven main types according to their structural features, and provided a number of review reports published recently about lignans. A tabular compilation of the molecular structures of known lignans is presented at the end of this survey report. A total of 111 references were considered for this survey report.