Bol’shie Vyazemy, Odintsovskii Region, Moscow Province, 143050 Russia, e-mail dzhavakhiya@yahoo.com, tatiana.voinova@bk.ru, unavil@yandex.ru, nataafg@gmail.com, mod-39@list.ru, makeev@vniif.ru, larisa@vniif.ru Acknowledgements: Supported financially by Russian Science Foundation (RSF project ¹ 14-16-00150) Received May 26, 2016 A b s t r a c t The control of the mycotoxin contamination of agricultural products represents a serious problem of the global food and feed industry. <...> Aflatoxin B1 (AFB1) is one of the most dangerous mycotoxins due to its hepatotoxicity, carcinogenicity, and temperature resistance. <...> Thus, the search for substances able to block its biosynthesis and, therefore, to prevent the toxin accumulation in food and feed is still relevant. <...> This paper is devoted to the study of the ability of some natural and synthesized compounds to block the biosynthesis of AFB1 and/or melanin (both are secondary metabolites, which have common intermediates and common initial stages of the polyketide biosynthetic pathway) in toxigenic Aspergillus flavus. <...> The studied compounds included lovastatin, and several commercial compounds: (aminoethyl)thiophosphonic acid, (aminomethyl)thiophosphonic acid, alafosfalin, (1aminoethyl)phosphonic acid, and N-hydroxyputrescine. <...> A mutant Aspergillus terreus strain 45-50 obtained earlier from the A. terreus ATCC 20542 was used as the lovastatin producer. <...> N-hydroxyputrescine and some phosphoanalogues of amino acids were assessed by their influence on the pigmentation of fungal colonies grown on solid medium and on the specific AFB1 content in cultural broth determined after the cultivation of a fungus on liquid nutrition medium. <...> To reveal changes in the colony morphology, toxigenic A. flavus strain AF11 was cultivated on agarized medium. <...> To determine the effect of tested compounds on the AFB1 production, AF11 was cultivated for 170 h in a liquid Payne-Hagler medium. <...> Solutions of the tested compounds were added to the medium up to the final concentration of 0.001-0.1 % (commercial compounds) or 0.0001 to 0.001 % (lovastatin). <...> In addition, the effect of lovastatin on the AFB1 accumulation in wheat grain contaminated with A. flavus AF11 was assessed. <...> The supplement of the nutrition medium with (aminoethyl)thiophosphonic acid, (aminomethyl)thiophosphonic acid, and alafosfalin caused a significant decrease in the AFB1 production, but did not influenced on the colony pigmentation. <...> N-hydroxyputrescine and (1aminoethyl)phosphonic acid were able to partially or completely block <...>