UDC: 615.276:547.789:542.91

Aim. Based of the Knoevenagel condensation reaction the synthesis of new rhodanine-indoline hybrid molecules for screening antibacterial and antifungal activities was accomplished. Methods. Organic synthesis, NMR spectroscopy, pharmacological screening. Results. The reaction between rhodanine-3-propanoic/ethanesulfonic acids and indolecarbaldehydes in the acetic acid provided series of 5-indolylmethylenerhodanine-3-carboxylic/sulfonic acid derivatives. Based on the esterification reaction with methanol in the presence of sulfuric acid, 5-indolylmethylenerhodanine-3-propanic acid was transformed into appropriate ester for further evaluation of antimicrobial activity. The antimicrobial activity screening allowed the identification of compounds with significant effect against Escherichia coli, Staphylococcus lentus and Candida albicans with MIC/MBC/MFC values in the range of 25-50 μg/mL.
Conclusions. The synthesized 5-indolylmethylenerhodanine-3-carboxylic/sulfonic acid derivatives are a convenient platform for the development of new highly active and low-toxic agents as potential drug-like molecules with antimicrobial activity.
K e y w o r d s: synthesis, 2-thioxo-4-thiazolidinone, indolecarbaldehydes, spectral data, antimicrobial activity.

UDC 547.792.6:615.9:616-092.19-092.9

Keywords: 

2-thioxo-4-thiazolidinones, indolecarbaldehydes, synthesis, cellular immunity, phagocytosis, immunotropic activity, leukocytes, guinea pigs

Abstract

The aim. To study the cell immunity status under influence of 3-[5-(1H-indol-3-ylmethylene)-4-oxo-2-thioxo-thiazolidin-3-yl]-propionic acid, as a prominent 4-thiazolidinone derivative and a class of biologically active compounds with polypharmacological properties.

Materials and methods. Experimental method on the model of laboratory animals (guinea pigs); intradermal allergy tests; relative and absolute content in the peripheral blood of T- and B-lymphocytes subpopulations; hematological indexies: index of the ratio of lymphocytes and monocytes, index of the ratio of neutrophils and monocytes, index of the ratio of neutrophils and eosinophils, phagocytic index, phagocytic number; ELISA; organic synthesis; pharmacological screening.

Results. The effect of 3-[5-(1H-indol-3-ylmethylene)-4-oxo-2-thioxo-thiazolidin-3-yl]-propionic acid has antifungal properties and affect cellular component of immunity in vivo in the guinea pigs model. There are no changes in the skin of guinea pigs during and after chemical applications of the skin and after intradermal tests. The compound stimulate the immune cells, in particular the lymphocyte (increase in the absolute number of CD3 T-lymphocytes by 21.46 % and the absolute number of CD8 T-suppressors by 27.15 %), but with a selective inhibitory effect on certain units (decrease the relative number of NK cells CD16 by 11.57 % and B-lymphocytes CD22 by 23.08 %). There was an increase in the activity of the macrophage phagocytic system (increase in PN by 439.87 % and PI by 62.73 % at 120 minutes), which indicates the reliability of the absorbing function of phagocytes, but with a decrease in their ability to endocytosis (PCI decreased significantly by 78,72 %).

Conclusions. Synthesized 3-[5-(1H-indol-3-ylmethylene)-4-oxo-2-thioxo-thiazolidin-3-yl]-propionic acid has a selective activating effect on certain parts of cellular immunity and on phagocytic activity. Derivate influence on the phagocytic activity of neutrophils is ambiguous, and the effect of the compound directed to the cellular part of the immune system does not cause cellular immunodeficiency. The studied derivative is promising for further study of the drug-like molecule with antifungal and antitumor effects

The Knoevenagel reaction is an essential synthetic tool in the organic and medicinal chemistry of thiazolidin-4-one derivatives. In the present work, the application of ethylenediamine diacetate (EDDA) as an effective catalyst for the interaction of 2-thioxothiazolidin-4-one with 4-(tert-butyl)cyclohexanone is proposed. The structure of novel synthesized 5-[4-(tert-butyl)cyclohexylidene]-2-thioxothiazolidin-4-one (yield 61%) was confirmed by1H-,13C-NMR, LC-MS, IR, and UV spectra. Drug-like properties of the synthesized compound were evaluated in silico using the SwissAdme, and their potential antimicrobial activity against 15 strains of Gram-positive and Gram-negative bacteria as well as yeasts was evaluated in vitro. The synthesized compound possesses satisfactory drug-like parameters and promising antimicrobial properties and presents interest as a prospective intermediate for the forthcoming design of biologically active small molecules. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Author keywords

Antimicrobial activity; Catalyst; Ethylenediamine diacetate (EDDA); Knoevenagel reaction; Rhodanine

Multicomponent reactions effectively contribute to modern organic and medicinal chemistry. 4-Thiazolidinone core and cyclopropyl moiety are important structural motifs for design of potential biologically active molecules. In the present paper, the convenient step-economy and cost-effective synthesis of 2-(cyclopropylamino)-5-(4-methoxybenzylidene)thiazol-4(5H)-one (2) is described based on the application of the MCR methodology. The proposed approach includes direct one-pot interaction of 2-thioxothiazolidin-4-one (rhodanine), 4-methoxybenzaldehyde with cyclopropylamine which was used in 10% excess compare to other reagents. The structure of synthesized compound 2 was confirmed using 1H, 13C, 2D NMR, LC-MS, IR and UV spectra. The presence of prototropic amino/imino tautomerism for synthesized compound 2 was observed based on spectral analysis data. Screening of antimicrobial activity against 12 strains of Gram-positive and Gram-negative bacteria, as well as yeasts, was performed for synthesized derivative 2. © 2022 by the authors.

Author keywords

4-thiazolidinones; antimicrobial activity; cyclopropylamine; multicomponent reactions; rhodanine