Comparison of novel tetra-substituted phthalocyanines with their quaternized derivatives: Antioxidant and antibacterial properties

Abstract

In this study, we describe the synthesis and characterization of 2(3), 9(10), 16(17), 23(24)-tetrakis (4-(dimethylamino)benzyloxy) metal-free (2), zinc (II) (3) and cobalt (II) (4) phthalocyanines and comparison of their antioxidant and antibacterial properties with their quatemized derivatives (2a-4a). The antioxidant activities of the all synthesized compounds were emphasized by using three different methods. The results of the experiments showed that the highest DPPH (1,1-dipheny1-2-picrylhydrazyl) activity was determined to be 91.95 % for compound (2). In comparison, phthalocyanines containing 4-(dimethylamino)benzyloxy groups had similar DPPH activity with their quaternized derivatives. In the ferrous ion chelating activity and reducing power assays, compound (2a) showed the highest activity with 97.70 % for chelating activity and 2.34 mg/L for reducing power assay. In comparison, the quatemized derivatives (2a-4a) had much better chelating activity than the non-quatemized ones. However, they had less reducing power than the non-quatemized ones (2-4). In addition, the results of the antibacterial activity determination studies showed that only (2a) and (4a) compounds had good antibacterial activity against E.coli, B. Subtilis (ATCC 6051), B. Subtilis (ATCC 6633), B. Cereus (SBT8) and S. aureus bacteria with 16 - 21 mm inhibition zones. The positive results revealed that the quaternized derivatives (2a-4a) have good antioxidant and promising antibacterial properties.