Isatin Schiff Base Research Articles

Synthesis of novel 4-substituted isatin Schiff base derivatives as potential autophagy inducers and evaluation of their antitumour activity.

Induction of autophagic death in cancer cells is one of the promising strategies for the development of anti-cancer therapeutics. In the present study, we designed and synthesized a series of isatin Schiff base derivatives containing thioether structures. After discovering the highly active target compound H13 (IC50 = 4.83μM) based on in vitro antiproliferation, we also found it had a high safety against normal cells HEK293 with CC50 of 69.01μM, indicating a sufficient therapeutic window. In addition, to provide reference for subsequent studies, a model was successfully constructed by Sybyl software. Preliminary mechanistic studies suggested that H13-induced apoptosis may be closely related to ROS accumulation and mitochondrial dysfunction. Subsequent studies revealed that H13 inhibited cell proliferation by inducing cellular autophagy mainly through blocking signal of the PI3K/AKT/mTOR pathway. Altogether, these results suggested that H13 was potentially valuable as a lead compound.

Synthesis, Molecular Docking Study, Anti-Oxidant and Cytotoxicity Evaluation of New Spiro Six Membered Ring Derivatives of 5-nitro isatin

Spiro-5-nitro isatino six memberd ring (quinazoline-4-one, thiazine-4-one and oxazine-4-one) respectively were produced by a cycloaddition of 5-nitro isatin Schiff bases [1–5] with anthranilic acid, o-mercapto benzoic acid and salicylic acid. 1HNMR and 13CNMR nuclear magnetic resonance spectroscopies, as well as Fourier-transform infrared spectroscopy, were used to identify the structures of the obtained compounds. These spiro-5-nitro isatin are of interest to us due to their potential antioxidant and anticancer properties. The MTT assay ((3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide)) was used to examine in vitro bioactivity testing against breast cancer (MCF-7) cell lines which compound 14 (IC50=79.85, IC50=39) after 24 hours and 48 hours showed good cytotoxicity compared with drug reference tamoxifen. synthesized compounds 6-20 were evaluated for against antioxidant activity by using DPPH assay. In molecular docking, Promising compounds were used to reveal potential cytotoxic activity mechanisms.

Synthesis, Invitro Cytotoxic Activity and Optical Analysis of Substituted Schiff Base Derivatives.

Fluorescent cytotoxic compounds with readout delivery are crucial in chemotherapy. The growing demands of these treatment strategies require the novel heterocyclic molecules with better selectivity alongside fluorescence marker potential. In this context, a series of nine isatin Schiff base derivatives 4a-i were synthesized, characterized and evaluated for UV-visible, fluorescence, thermal and bioanalysis in order to explore the effect of structure on their bioprofiles. The analogue 4d exhibited maximum cytotoxic activity on Hella cells with percentage inhibition of 83% at 50 µM and 100% at 150 µM concentrations while 4c showed minimum cytotoxic activity with the value of 19% at 50 µM and 22% at 150 µM concentrations. Meanwhile, 4g was found to exhibit maximum inhibition potential towards Vero Cells with the percentage inhibition values of 83 at 50 µM concentration. The overall SAR study showed that the para-fluoro-substituted isatin moieties exhibited the appreciable percentage inhibition while the least activity was delivered by the isatin derivatives with para-bromo substitution.

Synthesis, Characterization, Antimicrobial and In Silico Studies of Isatin Schiff Base Linked 1,2,3-Triazole Hybrids.

A new series of isatin-Schiff base linked 1,2,3-triazole hybrids has been synthesized using CuAAC approach from (E)-3-(phenylimino)-1-(prop-2-yn-1-yl)indolin-2-one derivatives in high yield (73-91 %). These synthesized derivatives were characterized using FT-IR, 1H NMR, 13C NMR, 2D-NMR and HRMS spectral techniques. The in vitro antimicrobial activity assay demonstrated that most of the tested hybrids exhibited promising activity. Compound 5 j displayed significant antibacterial efficacy against P. aeruginosa and B. subtilis with MIC value of 0.0062 μmol/mL. While, 5 j also showed better antifungal potency against A. niger with MIC value of 0.0123 μmol/mL. The docking studies of most promising compounds were performed with the well-known antibacterial and antifungal targets i. e. 1KZ1, 5TZ1. Molecular modelling investigations demonstrated that hybrids 5 h and 5 l exhibited good interactions with 1KZN and 5TZ1, with binding energies of -9.6 and -11.0 kcal/mol, respectively. Further, molecular dynamics studies of the compounds showing promising binding interactions were also carried out to study the stability of complexes of these hybrids with both the targets.

Investigating the antibacterial potential of novel N-Boc isatin Schiff bases: Combining synthesis with in-vitro and in-silico studies

The abstract explores into the antibacterial efficacy of newly synthesized N-Boc isatin Schiff bases against a range of pathogenic bacteria, including multidrug-resistant strains. The characterization of the synthesized compounds was achieved through various spectroscopic methods including 1H NMR, 13C NMR, and HRMS techniques, providing detailed structural insights. The in vitro antibacterial assessments were conducted via the agar diffusion method, revealing that compounds 3a, 3d, 3g, and 3j exhibited potent activity against both gram-positive (B. subtilis, MRSA) and gram-negative (E. coli) bacterial strains, providing objective data on their effectiveness. Furthermore, compound 3j, which featured bromine substitution at C5 of N-allyl isatin, displayed significant inhibition zones of 27 mm and 20 mm against E. coli and VRE, respectively, surpassing the activity of ciprofloxacin used as a standard drug molecule, thereby providing specific results. The molecular docking studies against E. coli Peptide Deformylase complex further confirmed the antibacterial potential of the synthesized compounds, adding a scientific basis for their efficacy. Additionally, in silico ADME predictions indicated favourable oral bioavailability, highlighting the promise of N-Boc substituted isatin Schiff bases as potential candidates for the development of novel antibacterial agents, thus contributing to the objective evaluation of their pharmacokinetic properties. Consequently, our studies demonstrated that these compounds not only possess significant antibacterial activity but also show promising pharmacokinetic properties, positioning them as strong candidates for the development of new antibacterial agents.

Corrosion and inhibition studies on AISI 316 with AISI 410 fiber laser welded joints

In this investigation, the corrosion study was conducted on fiber laser welded joints of AISI 410 and 316L stainless steel plates using hydrochloric acid, basic, and salt medium, behavior in three different pH. The effects of three different corrosive atmospheres were examined using the weight loss method. The test sample which was exposed to 1 N hydrochloric acid medium for 48 Hours resulted in 0.006 g of weight loss. The maximum amount of corrosion was found in the acidic medium whereas the least was observed in the salt medium. The effectiveness of three distinct derivatives of 1H-indole-2,3-dione, each replaced with hydroxyl groups in various positions, in inhibiting corrosion. Among the three derivatives examined, it was observed that those with ortho and para hydroxyl group substitutions exhibited superior inhibitory properties.
 KEY WORDS: Fiber laser welding, Traverse speed, Corrosion study, Isatin Schiff base, Inhibitors
 Bull. Chem. Soc. Ethiop. 2024, 38(3), 811-823. 
 DOI: https://dx.doi.org/10.4314/bcse.v38i3.20

A novel isatin Schiff based cerium complex: synthesis, characterization, antimicrobial activity and molecular docking studies

In this work, a novel isatin-Schiff base L2 had been synthesized through a simple reaction between isatin and 2-amino-5-methylthio-1,3,4-thiadiazole. The produced Schiff base L2 was then subjected to a hydrothermal reaction with cerium chloride to produce the cerium (III)-Schiff base complex C2. Several spectroscopic methods, including mass spectra, FT-IR, elemental analysis, UV–vis, 13C-NMR, 1H-NMR, Thermogravimetric Analysis, HR-TEM, and FE-SEM/EDX, were used to completely characterize the produced L2 and C2. A computer simulation was performed using the MOE software program to find out the probable biological resistance of studied compounds against the proteins in some types of bacteria or fungi. To investigate the interaction between the ligand and its complex, we conducted molecular docking simulations using the molecular operating environment (MOE). The docking simulation findings revealed that the complex displayed greater efficacy and demonstrated a stronger affinity for Avr2 effector protein from the fungal plant pathogen Fusarium oxysporum (code 5OD4) than the original ligand. The antibacterial activity of the ligand and its Ce3+ complex were applied in vitro tests against different microorganism. The study showed that the complex was found to be more effective than the ligand.

New bis Schiff base of isatin derivatives: syntheses, characterization, and biological activity

In the current study, imesatin (A) was condensed with various aromatic aldehydes to create a number of new Schiff bases of isatin [B1-B6]. The imesatin were created by combining isatin and O-phenylenediamine. Utilizing FT- IR and 1H-NMR and 13CNMR techniques, the chemical structures of the produced compounds were verified. Staphylococcus aureus, a gram positive bacteria, and Klebsiella pneumonia, a gram negative bacteria, were used to evaluate the biological study at concentrations of 50 and 100 μg/mL. Derivatives were discovered to have biological activity against these bacterial growths.

Isatin-Schiff base functionalized graphene oxide as a highly selective turn-on fluorescent probe for the detection of Pd(II) via photoinduced electron transfer pathway

We investigated the use of isatin-Schiff base functionalized graphene oxide (ISBGO) as a selective fluorescent chemosensor for the detection of palladium ions. Selectivity tests indicated that over 23 metal ions tested, ISBGO (λex = 340 nm, λem = 504 nm) showed the highest affinity for Pd(II), displaying a 10.1-fold enhancement. Also, interference tests proved that in the presence of both Pd(II) and other metal ions, there was still high fluorescence intensity and no considerable quenching occurred. According to DFT and TD-DFT calculations, photo-induced electron transfer (PET) is responsible for the turn-on response produced by the chemosensor. Coordination of Pd(II) with ISBGO in fact blocks PET from imine nitrogen of 3-iminoindolin-2-one moiety to the benzene ring, which in turn leads to a turn-on response. In addition, Job’s plot analysis and Benesi-Hildebrand approach suggest that ISBGO preferably forms a 1:1 complex with Pd(II) with an association constant of 1.020 × 105 M−1. Moreover, FT-IR spectroscopy and DFT study showed that amide oxygen and imine nitrogen of 3-iminoindolin-2-one moiety acted as binding sites of ISBGO. High sensitivity, fast response, great degree of sensitivity, short life time, low detection limit of 32 nM combined with high association constant (Kf) of 1.020 × 105 M−1 and increased fluorescence quantum yield (Φf) of roughly 1.5-fold in the presence of Pd (II), highlight the role of ISBGO as an excellent probe for sensing Pd(II) in aqueous solution.

Synthesis, Characterization, and Preliminary Antimicrobial Evaluation of New Schiff Bases and Mannich Bases of Isatin

Till now, isatin derivatives have received a lot of interest in organic and medicinal chemistry due to their significant biological and pharmacological activities. Schiff’s and Mannich bases of isatins are an effective group of heterocyclic derivatives that play a significant role in medicinal chemistry as antimicrobial agents. In light of these facts, new Schiff bases and Mannich bases of isatin were synthesized. The monomer Mannich bases; 3(a-e) have been synthesized by reacting isatin with different secondary amines, piperidine, morpholine, and pyrrolidine, dimethylamine, diphenylamine, separately, and formaldehyde, while the dimer (5) formed by using piperazine and formaldehyde which then react separately with Phenylhydrazine to form new Schiff bases 4(a-e), and dimer Schiff base (6) as final products. The structures of the newly synthesized compounds were identified using two spectroscopic methods; (Fourier- transform infrared) FTIR and proton nuclear magnetic resonance spectroscopy (¹H-NMR) analysis. The preliminary in vitro antibacterial and antifungal screening results of new isatin derivatives [4(a-e) and 6] reported moderate to potent antimicrobial activity, the compound 4c exhibited moderate broad-spectrum antibacterial and antifungal activities compared to other derivatives. Moreover, compounds 4c and 6 have a good inhibitory effect against B. subtilis while amoxicillin (standard drug) shows no activity. For antifungal activity compounds (4a-c and 4e) have considerable activity towards C. albicans, whereas compound 4d exhibits slight activity and 6 of no activity.

Isatin Schiff bases: A green and sustainable Mg alloys corrosion inhibitor

Mg alloys have a good application prospect and are a structural material with great application potential. However, the corrosion resistance of Mg alloys are very poor, so it is possible to develop environment-friendly and pollution-free corrosion inhibitor to inhibit the corrosion of Mg alloys and study its inhibition mechanism. Three isatin Schiff bases were synthesized and used as Mg alloys corrosion inhibitors. The results showed that in a 0.5 wt% NaCl solution, all three corrosion inhibitors had a good corrosion inhibition effect on AZ91D. The corrosion inhibition mechanism was studied by various characterization methods.

Exploring the Effectiveness of Isatin–Schiff Base as an Environmentally Friendly Corrosion Inhibitor for Mild Steel in Hydrochloric Acid

A recent study has shown that Schiff base OHMHI is an effective inhibitor of the corrosion of mild steel in acidic media. The study utilized weight loss measurements and electrochemical techniques, such as EIS and potentiodynamic polarization, to analyze the corrosion inhibition efficiency of OHMHI. The results of the study show that the presence of OHMHI in the corrosive environment significantly reduced the corrosion rate of mild steel and increased its corrosion resistance. The impedance spectra analysis indicated that OHMHI was adsorbed on the surface of mild steel, providing a protective layer. The potentiodynamic polarization study confirmed the protective role of OHMHI by showing an increase in the passive current density of the mild steel in the presence of OHMHI. The inhibitory efficiency of OHMHI was found to be 96.1%, indicating that it is an effective corrosion inhibitor for mild steel. The study also investigated the optimal conditions for the use of OHMHI as a corrosion inhibitor, with a concentration of 0.5 mM and a temperature of 303 K being chosen. The Langmuir adsorption isotherm concept was used to demonstrate the physical and chemical adsorption of OHMHI on the surface of mild steel. Morphological investigations of the uninhibited and inhibited surfaces of the mild steel specimen were examined using scanning electron microscopy (SEM) analysis. Furthermore, computational investigations using density functional theory (DFT) and experimental data were merged to explore the corrosion inhibition efficiency and mechanism of inhibition. Although the results are promising, further studies are needed to determine the long-term effects of OHMHI on mild steel corrosion and to evaluate its effectiveness under different environmental conditions. Overall, the study highlights the potential of OHMHI as an effective corrosion inhibitor for mild steel in acidic media.

Synthesis, identification and evaluation of molecular docking and experimental anti-cancer and antioxidant activity of new spiro four membered ring derivatives bearing 5-nitro isatin

Spiro-5-nitro isatino aza-β-lactams were produced by a [2 + 2] cycloaddition of 5-nitro isatin Schiff bases [1–5] with different aromatic isocyanate and thioisocyanate. 1HNMR and 13CNMR as well as FTIR spectroscopies, were used to identify the structures of the obtained compounds. These spiro-5-nitro isatin aza- β-lactams interest to us due to their potential antioxidant and anticancer properties. The MTT assay was used to examine in vitro bioactivity testing against breast cancer (MCF-7) cell lines. From result data, compound 14 displayed IC50 values that were lower than those of the clinically used anticancer drug tamoxifen toward MCF-7 cells after 24 h while compound 9 after 48 h synthesized compounds [6–20] were evaluated for against antioxidant activity by using DPPH assay. In molecular docking, Promising compounds were used to reveal potential cytotoxic activity mechanisms.

Immobilizing Isatin-Schiff Base Complexes in NH2-UiO-66 for Highly Photocatalytic CO2 Reduction

Reducing carbon dioxide (CO2) via photocatalysis to carbon-based materials is a challenging process due to the complexity of the process and the production of several byproducts. Therefore, it is crucial to develop photocatalysts with high yield and selectivity for CO2 reduction. Herein, we present a strategy for creating high-performance catalysts by immobilizing Ni, Co, and Cu ions in NH2-UiO-66 by covalently linking the isatin-Schiff base metal complexes (IS) to the micropores. The as-synthesized NH2-UiO-66/IS-complex (66-IS-M, M = Ni, Co, Cu) photocatalysts exhibit special photocatalytic activity for the reduction of CO2 because of the immobilized metal ions serving as active sites during the reaction. Among them, 66-IS-Ni has a maximum CO generation rate of 1350 μmol g–1 h–1 and a CO selectivity of 87%, both of which are significantly higher than those of previously reported metal–organic framework (MOF)-based photocatalysts. Experimental characterizations and density functional theory (DFT) calculations reveal that the effective charge separation and lowered free energy of CO2 reduction on 66-IS-Ni promote CO2 conversion. This study presents a universal strategy for the uniform dispersion of molecular catalysts in amino-functionalized MOF for efficient photocatalytic applications.

Advancements in Schiff Bases of 1H-Indole-2,3dione: A Versatile Heterocyclic Compound in Pharmacological Field

Abstract:Heterocyclic compounds have specific structural peculiarities, imparting immense applications in various fields. This study has explored the medicinal importance of a captive heterocyclic compound, 1H-Indole-2,3dione, commonly known as isatin. The flexibility in the structure of isatin makes it more innovative to have applications in the biological and analytical fields. In this minireview, we have discussed Schiff bases of isatin having activities, such as antidiabetic, antioxidant, antidiabetic, antimalarial, antiviral, anticonvulsant, anti-inflammatory and analgesic activity, and also the importance of this compound in various fields based on the reports mainly focussed on the current and past couple of years.

Synthesis and Characterization Some of Metals (ƖƖ) Complexes' with Mixed Ligands of saccharinate and Isatin Schiff Base

This research paper includes synthesis and characterization of some complexes of Zn(II),Hg(II), Cd(II), Cu(II), Co(II), Ni(II) with mix ligands of saccharinate and Schiff base derived from Isatin. All the synthesized complexes have been characterized by elemental analysis, molar conductance, uv-visible, magnetic susceptibility, atomic absorption , infrared and 1H NMR spectroscopy ,Metal to ligand [M:L] ratio was obtained for all complexes in ethanol. The concluded chemical formulas of the complexes were [M(sac)2(L)2] ,where {M=(Zn(II) , Hg(II) ,Cd(II)} tetrahedral geometry and for the complexes [M(sac)2(L)(H2O)2] ,where (M=Co , Ni and Cu), were octahedral geometry, sac=saccharinate, and L=C14H10N2O2

SYNTHESIS AND ANTIMICROBIAL SCREENING OF 2,6-DIAMINOPYRIDINE SCHIFF BASES OF ISATIN DERIVATIVES

Objective: Synthesis and in vitro antimicrobial screening of 2,6-diaminopyridine Schiff bases of isatin derivatives.
 Methods: Isatin and it’s 5-substituted derivatives (S1-5) were prepared by Sandmeyer method and N2-Benzylidenepyridine-2,6-Diamine (M) was obtained by the reacting 2,6-diaminopyridine with benzaldehyde. Schiff bases (MS1-5) were prepared by reacting isatin derivatives (S1-5) with N2-Benzylidenepyridine-2,6-Diamine (M). Resultant compound structures were confirmed by some analytical techniques’ data. All synthesized compound were screened for in vitro antimicrobial activity by broth dilution methods against Staphylococcus aureus (MTCC-3160), Bacillus subtilus (MTCC-441), Escherichia coli (MTCC-452), Klebsiella pneumoniae (MTCC-432), Candida albicans (MTCC-183), Aspergillus flavus (MTCC-277) using ciprofloxacin and fluconazole as standard drugs.
 Results: All compounds exhibited better antibacterial activity compared to standard. Among all compounds, MS2 and MS4 were found most effective against all strains of bacteria. Only MS3 and MS5 showed antifungal activity against both fungal strains.
 Conclusion: All newly synthesized Schiff bases of isatin showed significant antibacterial activity against the tested strain of bacteria, only a few compounds were found effective as antifungal.

Isatin Schiff base is an effective corrosion inhibitor for mild steel in hydrochloric acid solution: gravimetrical, electrochemical, and computational investigation

This paper describes the synthesis and characterisation of an isatin Schiff base, namely 2-(2-oxoindolin-3-ylidene) hydrazinecarbothioamide (OHB). The chemical structure of OHB was elucidated through proton-nuclear magnetic resonance (1H-NMR), carbon-nuclear magnetic resonance (13C NMR), and Fourier-transform infrared (FT-IR) spectroscopic techniques. OHB was evaluated for its corrosion inhibition ability on mild steel specimens in 1 M HCl using gravimetrical methods and electrochemical measurements such as electrochemical impedance spectroscopy (EIS) and potentiodynamic techniques complemented with microscopic analysis. The results indicated that OHB is a mixed-type inhibitor and showed good corrosion inhibition, with a maximum corrosion inhibition efficiency of 96.7% at a concentration of 0.5 mM and 303 K. The inhibition performance increased with an increasing OHB concentration and decreased with increasing temperature. The inhibition efficiency was attributed to the formation of a protective film on the surface of the tested mild steel coupon. The electrochemical impedance studies also indicated that the charge transfer resistance increased with an increase in OHB concentration. The morphological analysis confirmed the inhibition performance of OHB and the protective barrier film conformed to Langmuir monolayer adsorption. The experimental and theoretical corrosion kinetics and thermodynamic parameters were in agreement and revealed that an adsorption film of Fe–N coordination bonds formed on the mild steel surface.

Novel Methodology for Synthesis and Computational Analysis of Zinc Complexes of Isatin Derivatives and Screening their Biological Activity

Background: Due to arising threats of microbial infectious diseases in the human population, and the development of resistance against therapeutics, novel medicinal agents are required to counteract antimicrobial resistance. Heterocyclic rings such as indole or pyrrole, have been acknowledged to possess various biological properties like antimicrobial, anticancer, antiviral, antitubercular, etc and metals such as platinum, vanadium, zinc, selenium, etc. also show therapeutic actions. Thus, this work focuses to turn heterocyclic ring compound (isatin) and metal (zinc) into a drug having antimicrobial potential. Objective: The objective of the study was to synthesize zinc complexes of isatin Schiff bases and evaluate for antibacterial and antifungal activity. Methods: Herein, the conventional method was used for the synthesis of isatin Schiff bases from isatin and different monosubstituted amines. Then, zinc complexes were prepared by using isatin Schiff bases and zinc acetate. Physicochemical characteristics such as Rf value and melting point were determined by TLC and decibel melting point apparatus respectively. All the complexes were characterized by FT-IR and 1H NMR techniques. Further, the final zinc complexes were screened for antimicrobial potential by the serial dilution method. Some computational studies were also done with the help of MOPAC 2016. Result: In the present work, 14 complexes of zinc are obtained in harmonious yield from isatin Schiff bases using zinc acetate. Amongst the studied complexes, Z-3, Z-4, and Z-12 depicted maximum antimicrobial activity. Conclusion: 14 complexes of zinc were prepared by using 14 isatin Schiff bases which were in turn prepared by isatin and different mono-substituted amines. Characterization of these complexes was done by using FT-IR and 1H NMR. All prepared metal complexes were obtained in appropriate yield. The synthesized complexes were screened for their antimicrobial potential.

Synthesis of Novel Urea and Sulfonamide Derivatives of Isatin Schiff Bases as Potential Anti-cancer Agents

Background: Among the many types of chemical scaffolds, isatin derivatives, including their Schiff bases, have been extensively studied to find novel therapeutic agents against cancer. Amide or urea groups containing derivatives were also discovered to be tyrosine kinase inhibitors. Objective: This study aims to find potent compounds by designing 16 novel urea and sulfonamide derivatives of isatin Schiff bases. Method: Compounds were tested against PC-3, HepG2, SH-SY5Y, A549 cancerous, and NIH/3T3 noncancerous cell lines using cell culture assay. Results: Among the tested compounds 7a, 7b, 7c, 7d, 7h, 8a, and 8f presented potential inhibitions against cellular proliferation activities of HepG2 cells with average IC50 values of 31.97, 42.13, 31.50, 47.98, 32.59, 43.44, and 37.81 μM, respectively. They showed better inhibition potencies than the reference compound doxorubicin, and its value was measured as 51.15 μM in the same culture assay. The cytotoxic activities of the compounds in other cell lines were found to be less potent compared to doxorubicin. Conclusion: In vitro experiments demonstrated that designed compounds have the first evidence that they might be active against hepatocellular carcinoma. According to ADME prediction results, all compounds presented drug-like and good metabolic properties.