Synthesis of an Activatable Tetra-Substituted Nickel Phthalocyanines-4(3H)-quinazolinone Conjugate and Its Antibacterial Activity.

Suhailah S. Al-Jameel,Suriya Rehman,Mohammad Azam Ansari,Tamer E. Youssef,Sultan Akhtar,Asma M. Elsharif,Hanan H. Mohamed

doi:10.1155/2019/5964687

Suhailah S. Al-Jameel, Suriya Rehman

Open Access

https://doi.org/10.1155/2019/5964687

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Abstract

The aim of this study was to synthesize a series of nickel(II)phthalocyanines (NiPcs) bearing four 4(3H)-quinazolinone ring system units, (qz)4NiPcs 4a–d. The electronic factors in the 4(3H)-quinazolinone moiety that attached to the NiPc skeleton had a magnificent effect on the antibacterial activity of the newly synthesized (qz)4NiPcs 4a–d against Escherichia coli. The minimum MICs and MBCs value were recorded for compounds 4a, 4b, 4c, and 4d, respectively. The results indicated that the studied (qz)4NiPcs 4a–d units possessed a broad spectrum of activity against Escherichia coli. Their antibacterial activities were found in the order of 4d > 4c > 4b > 4a against Escherichia coli, and the strongest antibacterial activity was achieved with compound 4d.

Highlights

We described a facile convenient synthesis of novel tetra-substituted nickel phthalocyanines based on the heterocyclic moiety (i.e., 4(3H)-quinazolinone ring system4NiPcs (4a–d))
Antibacterial properties of tetrasubstituted 4(3H)-quinazolinone nickel (II)phthalocyanine derivatives against Escherichia coli ATCC 25922 have been evaluated by determining Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) using agar dilution methods. e MICs and MBCs values of tetrasubstituted 4(3H)-quinazolinone nickel(II)phthalocyanine derivatives 4a, 4b, 4c, and 4d are summarized in Table 1. e minimum MIC and MBC value recorded were 4 and 8 mg/ ml for compound 4d, whereas compounds 4c, 4b, and 4a showed MICs values of 8, 8, and >16 and MBCs values of 16, 16, and >32 mg/ml, respectively. e antibacterial activities were found in the order of 4d > 4c > 4b > 4a against Escherichia coli, and the strongest antibacterial activity was achieved with compound 4d (Table 1)
E morphological and structural changes in Escherichia coli cells caused by tetra-substituted 4(3H)-quinazolinone nickel (II)phthalocyanine derivatives were further investigated by scanning electron microscopy (SEM). e untreated Escherichia coli cells were typically rod-shaped, intact, and normal having regular and smooth cell surface (Figure 5(a))

Summary

Introduction

Youssef and Hanack have described novel symmetrically and asymmetrically NiPcs bearing heterocyclic moieties for pharmaceutical application [16], in connection with a previous work and our current interest in the synthesis of Pcs derivatives functionalized with substituted heterocycles for biological evaluations [17, 18]. We described a facile convenient synthesis of novel tetra-substituted nickel phthalocyanines based on the heterocyclic moiety (i.e., 4(3H)-quinazolinone ring system (qz)4NiPcs (4a–d)). Antibacterial properties of tetra-substituted 4(3H)-quinazolinone nickel(II)phthalocyanine derivatives have not been yet explored. To the best of our knowledge, this is the first report which aims to modify the structural activity of nickel(II)phthalocyanines conjugate with four 4(3H)-quinazolinone units and evaluate their parameters required for the structure-function relationship for antibacterial properties. To the best of our knowledge, this is the first report which aims to modify the structural activity of nickel(II)phthalocyanines conjugate with four 4(3H)-quinazolinone units and evaluate their parameters required for the structure-function relationship for antibacterial properties. e antibacterial activity results obtained for the newly formed (qz)4NiPcs 4a–d show promising antibacterial properties against Escherichia coli

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Conclusion