Eman H. Ismail

Synthesis, spectroscopic and structural characterization, and antimicrobial studies of metal complexes of a new hexadentate Schiff base ligand. Spectrophotometric determination of Fe(III) in water samples using a recovery test

New Schiff base complexes were prepared using the bioactive antimicrobial bis-Schiff base ligand synthesized by condensation of 2-aminobenzoic acid and 2,2′-(ethylenedioxy)bis(benzaldehyde). The pKA value of the bis-Schiff base was determined through visible spectrophotometric experiments and the stability constants of its complexes were also studied. The structural features of the complexes were determined from their elemental analyses, magnetic susceptibility, molar conductance, and spectral (IR and 1H NMR) studies. Powder XRD indicates that all the complexes are amorphous except the Cr(III) and Cu(II) chelates which are crystalline. The data revealed that the stoichiometries of all prepared complexes are of 1:1 M/L type. The UV–vis absorption spectral data for the complexes suggest an octahedral geometry around the central metal ion. Thermogravimetric data (TG and DTG) were also studied. The kinetic and thermodynamic parameters for thermal decomposition of the complexes were calculated by graphical methods using the Coats–Redfern approach. The antimicrobial activity of the bis-Schiff base and its complexes was tested against a number of bacteria and fungi to assess their inhibiting potential. Most of the complexes exhibit antibacterial activity more than the parent bis-Schiff base. Also Cr(III), Co(II), and Ni(II) complexes have antifungal activity against Candida albicans whereas the parent bis-Schiff base is inactive. A recovery test was also applied for the spectrophotometric determination of Fe(III) in different natural water samples.Graphical abstract

Preparation and Identification of a New [Cr2(NTA)2(μ-OH2)]·2H2O Complex

[Cr2(NTA)2(μ-OH2)]·2H2O is prepared by heating nitrilotriacetic acid (H3NTA) with an aqueous suspension of freshly precipitated Cr2O3·nH2O. Elemental analysis, IR spectra, UV/vis spectra, X-ray diffraction, thermogravimetric analysis, mass spectra and magnetic susceptibility measurements suggest the existence of a Cr-Cr bond. One of the three water molecules acts as a bridging ligand (μ-H2O) while the other two are waters of crystallization.

Preparation, characterization and determination of acid dissociation and stability constants of some acid divalent-metal 1 : 2 nitrilotriacetate complexes

H2[MII(HNTA)2]·xH2O complexes of eleven divalent metals were prepared. These complexes were characterized via elemental analysis, IR spectra, TGA, DTA and 1H NMR. pKa1 and pKa2 of these acids were determined together with their log β 1 and log β 2 as metal complexes.

Auditory brainstem response in full term neonates born to mothers with iron deficiency anemia: relation to disease severity

Abstract Background: Iron is crucial for fetal brain development; however, there are insufficient data regarding the effects of maternal iron deficiency anemia (IDA) on auditory neural maturation. Aim: We evaluated the effect of maternal IDA on auditory brainstem response (ABR) in full-term neonates. Methods: Out of 223 pregnant women, 50 were diagnosed as having IDA and 50 healthy mothers were enrolled as controls. ABR test was done for the studied neonates within 48 hours after birth and at 3 months. Results: We found that hemoglobin and iron profile were lower in neonates born to anemic mothers compared with controls. Of 100 neonates screened for ABR, 25 failed the test (all of them were born to anemic mothers). The majority of neonates who failed the screening ABR test (88%) had latent iron deficiency (cord blood ferritin 11–75 µg/L). After 3 months, 85 neonates underwent diagnostic ABR test which revealed significantly prolonged interpeak latencies I–III, III–V, and I–V among neonates born to IDA mothers compared with the control group. Within the IDA group, all interpeak latencies were more prolonged in neonates with latent iron deficiency and in those born to mothers with serum ferritin <15 µg/L. Logistic regression analysis showed that maternal hemoglobin and mean corpuscular volume could predict neonatal ABR results. Conclusions: IDA during late pregnancy adversely affects cord blood iron and hearing status. ABR results are closely related to the severity of maternal and neonatal iron status. Antenatal screening of pregnant mothers is needed to improve fetal iron status and prevent abnormal auditory maturation.