Correlation of antioxidant activities with theoretical studies for new hydrazone compounds bearing a 3,4,5-trimethoxy benzyl moiety

Preparation, characterization and Microbicide activities of N'-((3-(hydroxyimino)butan-2-ylidene)-2-(phenylamino)acetohydrazide and its complexes

“…This mode of bonding is further supported by the new bands observed in the 638-575, 581-497 and 456-504 ranges related to (MO), two (MN)respectively [55]. The spectra of the bimetallic complexes (4), (8)(9) and (13)(14) suggested the chelation of the ligand in a dibasic tetradentate fashion bonding two metal ions by the three nitrogen atoms of amino, imine and oxima to groups and the enolic oxygen atom, which is supported by i) complete disappearance of the band of both hydroxyl of the oxime as well as the carbonyl group of the acetohydrazide moiety. ii) a negative shift in the position of the NH bands iii) the appearance of an additional band in the range 1500-1527assigned to the emerging of a new C=N group.…”

“…The observed separation value () (159-200) cm -1 between asymmetric and symmetric (COO -) groups indicate that the ligand acts as a mono-dentate in these complexes [62]. IR spectrum of the nitrate complexes (9,11) showed new bands at  5 (1432, 1412)and  1 (1366, 1329) cm -1 respectively referring presence of nitrate group in a coordination mode with the metal ion. The difference between ( 5 - 1 ) was in the range (74-81) cm -1 indicating that, the nitrate group bonded to the M(II) ion is uni-dentate fashion [61,63,64].…”

“…53.78%), refers to decomposition of the complex ending up with the formation the metal oxide.Cu(II) complex (8) (9) and (14) showed five decomposition steps. The first one involves loss of one, two hydrated water molecules with weight loss 3.38 and 5.56 % respectively, these weight losses accompanied with two endo thermic peaks at 90 and 85 o C in the DTA pattern of complex (9) and (14) respectively. The removal of the coordinated water molecules (one for complex (9) and three for complex (14) was accompanied with endothermic peaks at 180 and 170 o C and weight losses 4.23 and 9.16 % (calcd.…”

“…Complexes (4), (8), (9), (13) and (14) were found to afford M 2 L formulae while complex (11) adopted ML 2 formulae. The ligand acted as a neutral (bidentate [11], tridentate [6,7], monobasic (tridentate [2,3,5,12]), dibasic (tridentate [10], tetradentate [4,8,9,13,14]) chelating to the metal ions via nitrogen atoms of aceto-amino and azomethine groups, carbonyl oxygen atom in its enolic or ketonic form and/or protonated or deprotonated oximino nitrogen atom, adopting an octahedral, tetrahedral or square planar geometry around metal ions. The antimicrobial activity of the ligand, as well as the metal complexes, was examined using Amphotericin B and Amoxicillin as drugstandards against Aspergillus niger (A.niger) and Escherichia coli (E. coli) ,respectively.…”

“…Hydrazone ligands represent a class of Schiff base with an extra function group characterized by a nitrogen-nitrogen covalent bond that enhances their capability to form more stable metal complexes via reaction with most of the transition metal ions [6,7]. Both hydrazide and hydrazone compounds have drawn much concern in order to investigate their structures as well as their enormous biomedical activities as: antioxidant [8,9], analgesic, anti-inflammatory [10], antimalarial, anti-leishmanial and anti-trypanosomal [11], anti-convulsant [(12)], antibacterial [13,14], antiplatelet [15], antitumor [16] and antiviral [17,18] activities. The presence of active azomethine NHN=CH-protons in these compounds imparts them a major importance as good candidates for the development of new drugs [19][20][21].…”