Synthesis and Antimicrobial Activity of Sulfur Derivatives of Quinolinium Salts.

Anna Empel,Małgorzata Kępa,Tomasz J Wąsik,Danuta Idzik,Andrzej Zięba,Robert D Wojtyczka,Aleksander Sochanik,Ewa Kisiel

doi:10.3390/molecules23010218

Abstract

A novel method for cleavage of the dithiine ring in 5,12-(dimethyl)-thioqinantrenium bis-chloride 1 “via” reaction with sodium hydrosulfide leads to 1-methyl-3-mercaptoquinoline-4(1H)-thione 2. Further transformation of thiol and thione functions of compound 2 leads to a series of sulfide and disulfide derivatives of quinolinium salts 4 and 6. 1-Methyl-4-chloro-3-benzylthioquinoline chloride 8 was obtained by N-alkylating 4-chloro-3-benzylthioquinoline using dimethyl sulfate. Antimicrobial activity of the obtained compounds was investigated using six Gram-positive and six Gram-negative bacterial strains, as well as Candida albicans yeast. Greater activity was demonstrated towards Gram-positive strains. MIC values for compounds and with benzylthio 4d and benzoylthio 4f substituents in 3-quinoline position were found to be in the 0.5–1 μg/mL range, at a level similar to that of ciprofloxacin (reference). Compounds 4d and 4f also demonstrated interesting antifungal properties (MIC = 1).

Highlights

Increasing bacterial resistance to antibiotics has become a very serious medical problem for health care systems worldwide [1,2]
There have our previous papers, we described the synthesis of
In our trials demonstrated their strong antimicrobial properties we salts decided to previousSince papers,initial we described the synthesis of

Summary

Introduction

Increasing bacterial resistance to antibiotics has become a very serious medical problem for health care systems worldwide [1,2] This situation requires continued efforts in searching for novel classes of compounds with antimicrobial activities. Other examples of similar compounds include streptonigrin, produced by Streptomyces flocculus, an aminoquinone antitumor and antibacterial antibiotic [5] and camptothecin, a cytotoxic quinoline alkaloid isolated from the bark and stem of Camptotheca acuminata (Camptotheca, happy tree). Derivatives of the latter, topotecan and irinotecan, are anticancer drugs [6].

Methods

Results

Conclusion