• Mass Spectrometry Letters
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• v.6 no.3
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• pp.65-70
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• 2015

N-Alkyl/benzyl substituted isatin derivatives are intermediates and synthetic precursors for the preparation of biological active heterocycles. N-alkyl/benzyl isatins have showed various biological activities, such as cytotoxicity, antiviral, caspase inhibition, cannabinoid receptor 2 agonists for the treatment of neuropathic pain, etc. In this study, N-alkyl/benzyl isatin derivatives were synthesized from isatin and alkyl/benzyl halides in presence of K₂CO₃ in DMF and excellent to quantitative yields (~95%) were obtained. Isatins and benzyl-isatins were condensed with fluorescein hydrazide to form fluorescein hydrazone. All the compounds were subjected to their fragmentation behavior study using LC/MSⁿ. N-Alkyl substituted isatin derivatives fragmented at nitrogen-carbon (N-C) bond, hence gave daughter ion as [RN+H]⁺. Whereas, N-benzyl substituted isatin derivatives fragmented at carbon-carbon (C-C) bond of alkyl chain which linked with nitrogen molecules, therefore gave N-methyl fragments [RNCH₂]⁺. This study demonstrated that, isatin moiety present in a small/large molecule or in a matrix of reaction mixture with/without N-alkyl/benzyl substituents can be identified by mass spectroscopic fragmentation behavior study.

• YAKHAK HOEJI
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• v.18 no.1
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• pp.74-76
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• 1974

Oh heating isatin with aromatic monocarboxylic acids having .alpha.-hydrogen atoms such as p-nitrophenylacetic acid, p-methoxyphenyl acetic acid and .alpha.-naphthylacetic acid in the presence of anhydrous sodium acetate functioning as a catalyst, p-nitrobenzylidene-3-oxindole, p-methoxybenzylidene-3-oxindole and ${\alpha}$-naphthobenzylidene-3-oxindole are obtained, respectively. The results of these experiments show that isatin may be used as the carbonyl component in the condensation reaction.

• YAKHAK HOEJI
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• v.17 no.3
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• pp.141-146
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• 1973

Eight isatin N-Mannich bases were synthesized and tested their antimicrobial and antitumor activities. N-Piperidinomethylisatin-(N-cyclohexyl)-thiosemicarbazone is active against St. aureus at 10${\mu}$g/disk and isatin thiosemicarbazone against P. chrysogenum at 10${\mu}$g disk.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3391-3398
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• 2013

The carboxylated multiwall carbon nanotubes (MWCNT-COOH) and functionalized with isatin derivative (MWCNT-isatin) have been used as efficient adsorbents for the removal of lead (Pb) from aqueous solutions. The influence of variables including pH, concentration of the lead, amount of adsorbents and contact time was investigated by the batch method. The adsorption of the lead ions from aqueous solution by modified MWCNTs was studied kinetically using different kinetic models. The kinetic data were fitted with pseudo-first-order, pseudo-second-order, and intra-particle diffusion models. The sorption process with MWCNT-COOH and MWCNT-isatin was well described by pseudo-second-order and pseudo-first-order kinetics, respectively which it was agreed well with the experimental data. Also, it involved the particle-diffusion mechanism. The values of regression coefficient of various adsorption isotherm models like Langmuir, Freundlich and Tempkin to obtain the characteristic parameters of each model have been carried out. The Langmuir isotherm was found to best represent the measured sorption data for both adsorbent.

• Textile Coloration and Finishing
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• v.19 no.3
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• pp.6-11
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• 2007

The indigoid-type dyes based on isatin $\alpha-chloride$ were synthesized and the dyes were discussed with relevance to the "H-chromophore" or "cross-conjugated chromophore". The color-changed properties of the dyes were also investigated by means of visible absorption spectra. The novel dyes from isatin $\alpha-chloride$ are of theoretical interest and such dyes can be used as continuous pH indicators in acid/base titrimetric analyses.

• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.507-510
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• 2003

• Archives of Pharmacal Research
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• v.16 no.3
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• pp.180-185
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• 1993

The acid dissociation constants of certain Schiff bases derived from isatin with p-substituted benzoyl hydrazines and somee amino acids of glycine, $\beta$-and $\alpha$-alanine, valine, $\beta$-phenyl-$\alpha$-alanine and anthranilic acid have been detemined potentiometrically at different temperatures in different aquo-organic solvent mixtures (ethnol, dioxane, dimethyl formamide, methanol, acetone and tetrahydrofurance). The pKa values were demonstrated on the light of the different electornic and steric effects of the substituents and the sovlent characteristics. In all the mixed media used, ionization of the compounds decreased by increasing the mole fraction of the organic cosolvent. Theemodynamic parameters $(\Delta{H}^\circ,\;\Delta{G}^\circ,\;\Delta{S}^\circ)$ were evaluated. The structural effects of the investigated compounds on these parameters were reported and discussed.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.2
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• pp.123-129
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• 2003

Oxindoles(6a-g) are obtained by rhodium(II)-catalyzed Wolff rearrangement of diazoquinolinediones in moderate yields. Treatment of 6a-g oxindole derivatives reacted with CAN in acetonitrile at room temperature to gave 7a-g isatins in good yields. The structures of these compound were identified by MP, IR and NMR-spectra.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1761-1764
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• 2010

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.11-18
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• 2005

The nicotine converter genotypes of burley tobacco (Nicotiana tabacum L.), which convert nicotine to nornicotine, contain a high amount of nornicotine that degrades tobacco quality and smoking taste. Elimination of nicotine converter plants before seed harvesting is required for breeding nicotine low-converter lines and for increasing their seed production. This study aims to develop a rapid and convenient method of identifying nicotine converter plants of burley breeding lines of KB9118(KB108) using thin-layer chromatography (TLC) and isatin coloration method. Out of 223 plants in 10 lines harvested at maturity in 2002, 102 plants ($45\%$) were identified as nicotine converters by TLC of tobacco leaves air-cured. For 16 lines selected as low-converters in 2002, 148 plants grown in the field in 2003 were tested by the isatin coloration method using two detached leaves at the flowering stage thoroughly sprayed with $1\%\;NaHCO_3$ solution and cured in conditioned chambers for the early identification of nicotine to nornicotine conversion. From these samples, 46 plants ($31\%$) in 4 lines were identified as nicotine converters, indicating that the ratio of converters significantly decreased by one time selection. Mean percent conversion of non-screened lines was $14\%$ higher than that of following generation. Therefore in the burley tobacco, a rapid and convenient means of identifying and removing nornicotine converter plants by the isatin coloration method during growth in the greenhouse or field were effective in reducing the converter plants in the following generation.