RESUMO
AIM: This study was performed to isolate and characterize novel antifungal lipopeptide from Bacillus cereus. METHODS AND RESULTS: Elucidation of its chemical structure was carried out by electrospray ionization mass spectra (ESI-MS) and Fourier transform infrared spectroscopy (FT-IR). The compound is a cyclic heptapeptide and composed of amino acids, Leu-Asp-Val-Leu-Leu-Leu-Leu. The in vitro activity of Kannurin against various pathogenic yeasts was assessed by CLSI M27-A and moulds by M38-A. It demonstrated broad-spectrum, fungicidal activity against clinically relevant yeasts and moulds. Kannurin exhibited low haemolytic activity and remained active over a wide pH and temperature range. In addition, Kannurin did not bind with melanin particles and was as active in inhibiting biofilms. CONCLUSIONS: An antifungal surfactin-like lipopeptide produced by Bacillus cereus strain AK1 was purified and chemically characterized. We propose to name this lipopeptide compound 'Kannurin'. To our knowledge, this is the first report of Bacillus cereus producing surfactin-like lipopeptide antibiotic with stronger antifungal activity. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results provide a valuable contribution towards a better understanding of the lipopeptide of Bacillus cereus. Moreover, it raises the possibility of using as an alternative antibiotic in clinical medicine.
RESUMO
A novel 1,6-hexanediol diacrylate cross-linked resin was prepared that was subsequently functionalized by using chloromethyl methyl ether to afford a high-capacity resin. The resin exhibited good swelling and its application in the successful synthesis of a 13-residue peptide corresponding to the fragment of seminalplasmin has been illustrated. The resin was chemically inert at peptide synthetic conditions.
