Abstract Objectives: Isatin and 2-oxoindole are valuable synthetic building blocks with diverse biological properties, including antifungal, antibacterial, antitumor, and anticancer activities. Due to the growing threat of pathogen resistance to current antimicrobial, nematicidal, and antienzymatic agents, our research group focuses on discovering new compounds with promising biological potential. Methods: N-1 alkylated isatin was synthesized in the presence of K2CO3. The N-1 alkylated isatin was then reacted with 2-oxoindole in the presence of the acid-base catalyst ZrCl4 to afford N-1 alkylated isoindigo derivatives, which were characterized using 1H, 13C NMR, and FT-IR spectroscopy. The synthesized derivatives were evaluated for their antimicrobial activity against Dickeya sp., Streptomyces sp., Fusarium oxysporum, and Rhizoctonia solani, their nematicidal efficacy against the plant pathogen Meloidogyne incognita, and their inhibitory potential against acetylcholinesterase. Results and Discussion: Among all synthesized derivatives, the isoindigo compound VIj (3-(1-decyl-2-oxoindolin-3-ylidene)indolin-2-one) exhibited the highest biological activity. It demonstrated significant antibacterial activity, with MIC values of 39 and 36 μg/mL against Dickeya sp. and Streptomyces sp., respectively. Similarly, the compound showed remarkable antifungal activity, with MFC values of 278 and 292 μg/mL against Fusarium oxysporum and Rhizoctonia solani, respectively. Regarding its nematicidal activity, VIj displayed potent inhibition against Meloidogyne incognita. The LC50 and LC95 values for egg hatch inhibition were determined as 0.193 and 1.462 mg/mL, respectively, while for juvenile mortality, the LC50 and LC95 values were 0.152 and 0.995 mg/mL, respectively. Additionally, the inhibitory activity of VIj against the acetylcholinesterase enzyme of M. incognita was evaluated, revealing an IC50 value of 210.4 μg/mL. These findings highlight VIj as a novel scaffold with significant antimicrobial, antifungal, and nematicidal properties. Conclusions: Its promising biological activities make it a valuable candidate for the agrochemical sector, where such compounds are in high demand for potential agricultural applications.

Synthesis and Biological Evaluation of N-1 Alkylated Isoindigo Derivatives: Antimicrobial, Antinematicidal, and Acetylcholinesterase Inhibition for Agrochemical Application

期刊论文
发表日期：

2025年12月1日

查看全文

Gurbir Kaur,
Divya Utreja,
Anu Kalia,
Sukhjit Kaur,
Yadhu Suneja

摘要

Abstract

Objectives: Isatin and 2-oxoindole are valuable synthetic building blocks with diverse biological properties, including antifungal, antibacterial, antitumor, and anticancer activities. Due to the growing threat of pathogen resistance to current antimicrobial, nematicidal, and antienzymatic agents, our research group focuses on discovering new compounds with promising biological potential. Methods: N-1 alkylated isatin was synthesized in the presence of K₂CO₃. The N-1 alkylated isatin was then reacted with 2-oxoindole in the presence of the acid-base catalyst ZrCl₄ to afford N-1 alkylated isoindigo derivatives, which were characterized using ¹H, ¹³C NMR, and FT-IR spectroscopy. The synthesized derivatives were evaluated for their antimicrobial activity against Dickeya sp., Streptomyces sp., Fusarium oxysporum, and Rhizoctonia solani, their nematicidal efficacy against the plant pathogen Meloidogyne incognita, and their inhibitory potential against acetylcholinesterase. Results and Discussion: Among all synthesized derivatives, the isoindigo compound VIj (3-(1-decyl-2-oxoindolin-3-ylidene)indolin-2-one) exhibited the highest biological activity. It demonstrated significant antibacterial activity, with MIC values of 39 and 36 μg/mL against Dickeya sp. and Streptomyces sp., respectively. Similarly, the compound showed remarkable antifungal activity, with MFC values of 278 and 292 μg/mL against Fusarium oxysporum and Rhizoctonia solani, respectively. Regarding its nematicidal activity, VIj displayed potent inhibition against Meloidogyne incognita. The LC₅₀ and LC₉₅ values for egg hatch inhibition were determined as 0.193 and 1.462 mg/mL, respectively, while for juvenile mortality, the LC₅₀ and LC₉₅ values were 0.152 and 0.995 mg/mL, respectively. Additionally, the inhibitory activity of VIj against the acetylcholinesterase enzyme of M. incognita was evaluated, revealing an IC₅₀ value of 210.4 μg/mL. These findings highlight VIj as a novel scaffold with significant antimicrobial, antifungal, and nematicidal properties. Conclusions: Its promising biological activities make it a valuable candidate for the agrochemical sector, where such compounds are in high demand for potential agricultural applications.