4. Biological activity of mixed ligand Fe(III) complexes with bioactive ligands

#### 4.1. The study of antibacterial activity of Fe Complex

#### 4.1.1. The effect of microorganisms and media

Salicylhydroxamic acid (SHAM) and its binary and ternary complexes (I–VI) were screened [47] to do an experiment to test its antibacterial activity on six bacterial strains: Escherichia coli (E.c.), Staphylococcus aureus (S. a.), Enterobacter cloacae (E. c.), Salmonella gallinarum (S. g.), Bacillus subtilis (B. s.), and Pseudomonas aeruginosa (P. a.). This experiment is illustrated in Table 6. These strains were obtained from the Microbial Centre of Ain Shams University, Egypt. Some other microorganisms like (Aspergillus fumigatus (A. f.), Candida albicans (C. a.), Alternaria alternata (A. a.), Penicillium italicum (P. i.), Saccharomyces cerevisiae (S. c.), and Microsporum canis (M. c.) were used for the fungistatic evaluation. These were later provided by the National Research Centre and the Microbial Centre of A in Shams University, Egypt. The media used were Mueller Hinton agar medium, tryptic soy broth (TSB), (ICN, biochemical Co., USA).


I, II, III, IV, V, VI are complexes of SHAM (I-VI) Cu(SHAM)2�2H2O (I), Ni(SHAM)2�2H2O (II), Fe(SHAM)2�2H2O (III), [Cu(Phen)(SHAM)] (IV), [Ni(Phen)(SHAM)] (V), [Fe(Phen)(SHAM)] (VI), and the reference drug (A) against six bacterial species and six fungi species in the agar disc diffusion method measured by diameter of inhibition zones (DIZ, mm).

Table 6. Antimicrobial activities of SHAM and its complexes.

#### 4.1.2. The calculation of minimum inhibitory concentration (MIC)

The apparatus used for the experiments are 0.5 mL volume 96-well microplates (ICN Biochem. Co., USA). Fill the first row of wells in each of 96-well microdilution plates with 100 μL of double strength TSB and fill the others with single strength TSB. Dilute the test compound and pour 100 μL in the first row. Every well filled must have its content mixed. The mixing technique based on suctioning and dispensing its content back five times. Take 100 μL from the first row and fill the second one. Then take from the second and fill the third. Repeat this procedure until the 23 rows. Each organism was experimented twice and the experiment as a whole was repeated three times. Before inoculating the 96 well plates with 96-prong inoculator, this later was in the inoculums. The microdilution plates were sealed with tape to prevent the drying of samples. At the end, plates were incubated at suitable temperatures to allow the growth to start. The growth was observed after 1 day.

Metal complexes of salicylhydroxamic acid (SHAM) and 1,10-phenanthroline (PHEN)

This stable can be summarized in the following points:


The bacteria used were (S.a.), (S.g.), (B.s.), (P.a.), (E.c.), and (E.c.). While the fungi used were (A.f.), (C.a.), (A.a.), (P.i.), (S.c.), and (M.c.). The reference drugs: (A) Ampicillin (H2O).
