engleski

Novel amino acid-primaquine derivatives as inhibitors of biofilm formation

Recently we have described preparation [1] and evaluation of antiproliferative [2], antioxidative [2] and antimalarial activity [3] of novel amino acid-primaquine ureidoamides 1a-f. In order to further investigate their biological activity, we found it worth to test their antimicrobial effects against a panel of Gram-positive, Gram-negative bacteria and fungal species. The title compounds showed very weak antimicrobial activity, with the exception of compounds 1a and 1d which exhibited moderate activity against some bacterial species. However, we have also tested the efficacy of compounds 1a-e on the biofilm formation by different bacterial and yeast strains. The results, expressed as minimum biofilm eradication concentration (MBEC), showed that the potency against biofilm formed by Escherichia coli ATCC 8739 and ATCC 10536 of all tested compounds was rather prominent, with even lower MBEC than that of the referent antibiotic gentamycin (MBEC = 25 µg/mL), especially for compounds 1a and 1c (MBEC = 6.25 µg/mL). The same compounds were also very potent as inhibitors of biofilm formed by Pseudomonas aeruginosa ATCC 27853, and somewhat less potent against P. aeruginosa ATCC 9027. Compound 1a had MBEC for S. aureus ATCC 6538 comparable with MBEC of gentamycin. On the other hand, none of the tested ureidoamides was effective against biofilm formation by Enterococcus faecalis. MBECs of almost all tested compounds against biofilm formed by Candida albicans ATCC 10231 and ATCC 90028 was at the level of referent antimicotic amphotericin, especially for the latter strain. The highest activity against biofilm formation by C. kefyr showed compounds 1d, 1e and 1f (MBEC = 25, 6.25 and 6.25 µg/mL, respectively). However, it has been found that the compounds are not effective against biofilm formation by C. parapsylosis ATCC 22019, C. tropicalis ATCC 750 and C. krusei ATCC 14243. Having in mind all the above mentioned facts, the tested ureidoamides 1a-f could serve as lead compounds in the development of novel inhibitors of biofilm formation.

primaquine ; amino acid ; biofilm

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