Microwave-assisted synthesis of borneol esters and their antimicrobial activity

Nat Prod Res. 2018 Jul;32(14):1714-1720. doi: 10.1080/14786419.2017.1399380. Epub 2017 Nov 10.

Abstract

Seventeen borneol esters (1-17) were synthesised by conventional and microwave-assisted methodology using DIC/DMAP, and seven are described for the first time (8, 9, 10, 12, 13, 16 and 17). The microwave-assisted methodology was carried out without use of solvents, displayed short reaction times, and showed equal or higher yields for all the long-chain esters and three aromatic compounds (11, 12 and 14) when compared to the conventional approach. All the borneol esters were evaluated against the bacteria Streptococcus sanguinis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and the fungus Candida albicans. Compounds 12, 13 and 14 displayed promising antibacterial activity with a MIC equal to ampicilin (62.5 mg mL-1) for some microorganisms. In fact, bornyl 3',4'-dimethoxybenzoate (13) was active against all tested bacteria and fungus.

Keywords: Borneol esters; DIC/DMAP; antibacterial activity; microwave irradiation.

MeSH terms

  • Anti-Bacterial Agents / chemical synthesis
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Anti-Infective Agents / chemical synthesis*
  • Anti-Infective Agents / chemistry
  • Anti-Infective Agents / pharmacology*
  • Benzoates / chemical synthesis*
  • Benzoates / chemistry
  • Benzoates / pharmacology*
  • Camphanes / chemistry*
  • Camphanes / pharmacology*
  • Candida albicans / drug effects
  • Chemistry Techniques, Synthetic
  • Drug Evaluation, Preclinical / methods
  • Escherichia coli / drug effects
  • Esters / chemistry
  • Microbial Sensitivity Tests
  • Microwaves
  • Pseudomonas aeruginosa / drug effects
  • Staphylococcus aureus / drug effects

Substances

  • Anti-Bacterial Agents
  • Anti-Infective Agents
  • Benzoates
  • Camphanes
  • Esters