Biological Properties of Schiff Bases and Azo Derivatives of Phenols

Abstract

Aza-derivatives of phenols such as Schiff bases and hydrazones are an important and interesting group of chemical compounds. They exhibit a number of biological activities and play an important role in the regulation of many biochemical processes. Due to these properties, these compounds are potentialy useful for the design and production of novel anticancer, antimalaria, antivirus and antimicrobial drugs.The primary aim of the present review is to compare selected groups of phenol-derivatives containing azo-, heterocyclic, aromatic, alkyl and sugar moieties in view of their potential use and undesired effects, since some of them are widely used as dyes in the industry.Despite the vast number of azo derivatives of phenols which were synthesized and tested with respect to their biological activities, there is a continuous search for compounds of this group which might exhibit interesting, new biological effects.The main contribution to the development of Schiff base chemistry undoubtedly came from pharmaceutical research that began with the early studies of Hugo Schiff in the 19th century. Indeed, a vast number of publications on this matter underline the relevance of Schiff bases and related compounds in chemistry, pharmacy, biochemistry and industry. GOSSYPOLGossypol (Scheme 1) is a bisesquiterpene with interesting physico-chemical properties and pronounced biological activities. Despite many useful biological and physiological characteristics the main obstacle in using this compound as a drug is its relatively high toxicity and some other side effects [1][2][3][4][5]. The toxicity of gossypol is directed mainly towards the reproductive system, liver, heart and lipid membranes [6,7]. In the last thirty years biological and medical applications of gossypol and its derivatives mainly of its Schiff bases were on the focus of research. More than two thousand publications about gossypol and its derivates in medical therapy show the importance of this compound today. Scheme 1.

A new azo‐Schiff base: Synthesis, characterization, biological activity and theoretical studies of its complexes

“…The electronic spectrum for this complex showed two broad peaks at 15384 and 19193 cm −1 , assigned to 4 T 1g ! 4 A 2g (ν 2 ) and 4 T 1g (F) ! 4 T 1g (P) (ν 3 ) transition, respectively and 25062 cm −1 , assigned to M !…”

“…[1,2] Azo-Schiff bases, having imine groups (C = N), are formed by the condensation reaction of (NH 2 ) primary amines with (CHO) aldehydes or (CO) ketones. [3][4][5][6][7][8] These compounds had been used for industrial purposes such as pigments, catalysts, liquid-liquid extraction, active transport, intermediates in organic synthesis and as polymer stabilizers. [9][10][11][12][13] Thus, they play an important role in revealing the preferred coordination geometries of metal complexes due to their preparative accessibility, diversity and structural variability.…”

Synthesis, Characterization and Antimicrobial Studies of Schiff Base Ligand-Derived from Amoxicillin and Benzaldehyde

“…Structurally a Schiff base is a nitrogen analogue of a carbonyl compound in which the carbonyl group is replaced by an imine or azomethine group (Dhar et al, 1982). The imine group in these compounds is proved to be responsible for various biological activities, antibacterial and antifungal being prominent (Przybylski et al, 2009). The general formula of a Schiff base is RHC = N-R1, where R and R1 are alkyl, aryl, cycloalkyl or heterocyclic groups (Arulmurugan et al, 2010).…”

2-Aminobenzothiazole Containing Novel Schiff Bases Derivatives: Search for New Antibacterial Agents

“…[13] Schiff bases have also been shown to exhibit a broad range of biological activities such as antiviral, antibacterial, anti-inflammatory, antimalarial, antifungal, anti-proliferative and antipyretic properties. [14,15] Imine or azomethine groups are present in various natural, naturally-derived, non-natural compounds and some compound which shows various biological activities. [16,17].…”