# Oxolane Ammonium Salts (Muscarine-Like)—Synthesis and Microbiological Activity

## TL;DR

This paper describes the synthesis of new muscarine-like compounds and tests their antimicrobial activity against various bacteria and yeast strains.

## Contribution

The synthesis of eight new oxolane ammonium salts with a quaternary nitrogen atom and evaluation of their antimicrobial potential.

## Key findings

- The crystal structure of the pyridinium derivative showed high similarity to muscarine's conformation.
- The compound with a decyl chain was the most active against tested microbes.
- The synthesized compounds were confirmed using NMR, MS, and IR analyses.

## Abstract

Commercially available 2-deoxy-D-ribose was used to synthesize the appropriate oxolane derivative—(2R,3S)-2-(hydroxymethyl)oxolan-3-ol—by reduction and dehydration/cyclization in an acidic aqueous solution. Its monotosyl derivative, as a result of the quaternization reaction, allowed us to obtain eight new muscarine-type derivatives containing a quaternary nitrogen atom and a hydroxyl group linked to the oxolane ring. Their structure was fully confirmed by the results of NMR, MS and IR analyses. The crystal structure of the pyridinium derivative showed a high similarity of the conformation of the oxolane ring to previously published crystal structures of muscarine. Two reference strains of Gram-negative bacteria (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853), two reference strains of Gram-positive staphylococci (Staphylococcus aureus ATCC 25923 and Staphylococcus aureus ATCC 29213) and four reference strains of pathogenic yeasts of the genus Candida spp. (Candida albicans SC5314, Candida glabrata DSM 11226, Candida krusei DSM 6128 and Candida parapsilosis DSM 5784) were selected for the evaluation of the antimicrobial potential of the synthesized compounds. The derivative containing the longest (decyl) chain attached to the quaternary nitrogen atom turned out to be the most active.