Successively Substituting an Additional 4-(2-Aminoethyl) Aniline Group in Fabricated Isoindoline-1,3-Dione Scaffold Enhances the Antimicrobial Potency: Part II of Research

The irrational use of antimicrobial agents for several decades has led to the drug-resistance among the patient population [1]. Overcoming the present drug-resistance is a major challenge for modern day scientists. In order to counter this problem, several approaches have been utilized, one of which involve drug design and discovery, where new classes or unexplored chemical moieties are explored for a particular activity, either serendipitously or quite rationally [2]. In the same way, in our previous research (Part-I of Research), based on the research evidence that phthalimide based compounds have gained adequate attention as anti-infective (anti-fungal, anti-microbial, anti-retroviral, anti-influenza, anti-malarial, and anti-tubercular) very recently [3]. Previously, we developed some potential phthalimide based compounds (2-((2-(4-substituted-phenyl) hydrazinyl) methyl) isoindoline-1,3-dione) derived from N-chloromethyl phthalimide by reacting with aromatic hydrazine derivatives and screened for anti-microbial studies against two Abstract


Research Article Introduction
The irrational use of antimicrobial agents for several decades has led to the drug-resistance among the patient population [1].
Overcoming the present drug-resistance is a major challenge for modern day scientists. In order to counter this problem, several approaches have been utilized, one of which involve drug design and discovery, where new classes or unexplored chemical moieties are explored for a particular activity, either serendipitously or quite rationally [2]. In the same way, in our previous research (Part-I of Research), based on the research evidence that phthalimide based compounds have gained adequate attention as anti-infective (anti-fungal, anti-microbial, anti-retroviral, anti-influenza, anti-malarial, and anti-tubercular) very recently [3]. Previously, we developed some potential phthalimide based compounds (2-((2-(4-substituted-phenyl) hydrazinyl) methyl) isoindoline-1,3-dione) derived from N-chloromethyl phthalimide by reacting with aromatic hydrazine derivatives and screened for anti-microbial studies against two

Abstract
The irrational use of antimicrobial agents for several decades has led to the drug-resistance among the patient population. Overcoming the present drug-resistance is a major challenge for modern day scientists. In order to counter this problem, several approaches have been utilized, one of which involve drug design and discovery, where new classes or unexplored chemical moieties are explored for a particular activity, either serendipitously or quite rationally. Learning lessons from the previously synthesized four compounds (Part-I of Research), we have now (Part-II of Research) designed two compounds (3 and 5) by incorporating an additional 4-(2-aminoethyl)aniline group in the fabricated isoindoline-1,3-dione scaffold by successive synthetic step utilizing similar protocol and screened them against the above four mentioned pathogenic microbes in a similar way. The present exploration is an attempt to rationally overcome the microbial drug resistance by the efficacious and potent nature of the compounds. Compound (5) exhibited the highest activity against A. niger with ZOI diameter of >29mm. All the compounds showed more or less nearly the same activity. From this study, it may be concluded that substituting the amine/amide-based components leads to an increase in the potency of the compared along with better-anti-fungal activity. Therefore, the current exploration helped to design the compounds which have better potency than our previous reports and also providing imperative knowledge regarding the selection of the substituents. The encouraging results will further motivate us in developing novel and better inhibitors of phthalimide scaffold in the future. 177 prominent species of bacteria; Escherichia coli and Staphylococcus aureus, and the fungal species, Candida albicans and Aspergillus niger [4]. The observed results were not very impressive, in terms of potency (50 μg/mL) as compared with the standard drugs. All the compounds demonstrated both bactericidal and fungicidal activity in a moderate depth. However, the measured activities were observed to be nearly the same and a very reasonable conclusion was not able to draw from the previous study at all. Therefore, learning lessons from the previously synthesized four compounds, we have now (Part-II of Research) designed two compounds by incorporating an additional 4-(2-aminoethyl)aniline group in the fabricated isoindoline-1,3-dione scaffold by successive synthetic step utilizing similar protocol and screened them against the above four mentioned pathogenic microbes in a similar way. The present exploration is an attempt to rationally overcome the microbial drug resistance by the efficacious and potent nature of the compounds.

Synthesis of Target Compounds
The synthesis involved chemical reaction of

Chemistry
The obtained spectra revealed several imperative facts which The amide (-NH) portion was positioned prominently adjacent to the amine at >3150 cm -1 in FT-IR spectra. The compound (5) had no specific amine group and therefore the FT-IR spectra did not show any characteristic peak in the range of 3200-3350 cm -1 in FT-IR spectra. When compared with the FT-IR spectra of the starting material (1), distinct differences were observed. The presence of no amine group was a discrete feature which helped to distinguish from compound (3) and was an appropriate evidence for the creation of the proposed compounds. The 1 H-NMR of the molecules additionally supported the above-mentioned data completely.
The amide components were predominantly found at 4 ppm. The  of the compared along with better-anti-fungal activity. Therefore, the current exploration helped to design the compounds which have better potency than our previous reports, and also providing imperative knowledge regarding the selection of the substituents. better-anti-fungal activity. Therefore, the current exploration helped to design the compounds which have better potency than our previous reports and also providing imperative knowledge regarding the selection of the substituents. The encouraging results will further motivate us in developing novel and better inhibitors of phthalimide scaffold in the future.