Targeted synthesis of dipeptides containing derivatives of -phenylalanine and study of their antifungal activity

New dipeptides containing derivatives of phenylalanine, N-tert-butoxycarbonyl-(S)-alanyl-(S)-[ALPHA]-methylphenylalanine and N-tert-butoxycarbonyl-(S)-alanyl-(S)-[ALPHA]-methyl-4-fluorophenylalanine, were synthesized. The antifungal activity of initial non-protein amino acids, derivatives of phenylalanine, and synthesized dipeptides was studied by selecting widely spread pathogenic and conditionally pathogenic fungal strains as test fungi: Aspergillus versicolor 12134, A. flavus 10567, A. candidus 10711, Penicillium chrysogenum 8190, P. aurantiogriseum 12053, P. funiculosum 8258, Alternaria alternata 8126, Ulocladium botrytis 12027, and Aureobasidium pullulans 8269. The studies showed that the antifungal activity of (S)-[ALPHA]-methyl-phenylalanine amino acid was pronounced against P. aurantiogriseum 12053 and Ulocladium botrytis 12027 fungal strains when applied at a concentration of 0.177 mg/ml; the dipeptide containing the mentioned amino acid showed a high inhibitory effect on the P. aurantiogriseum 12053 strain, exhibiting the same degree of inhibition at concentrations of 0.232 mg/ml and higher. (S)-[ALPHA]-methyl-4-fluorophenylalanine amino acid most significantly suppressed the growth of P. aurantiogriseum 12053, P. funiculosum 8258, Ulocladium botrytis 12027, and Aureobasidium pullulans 8269 fungal strains when a 0.195 mg/ml solution was used. The growth of the P. aurantiogriseum 12053 strain was inhibited even at a lower concentration of 0.13 mg/ml; the dipeptide containing the amino acid significantly inhibited the growth of the P. aurantiogriseum 12053 strain when applied at a concentration of 0.369 mg/ml. Keywords: peptides, antifungal, synthesis