Synthesis of New Phosphonylated Bis-1,3,4-oxadiazoles and Study of Their Antimicrobial and Antiviral Activity

A series of new bis-1,3,4-oxadiazoles was synthesized by reacting the corresponding dicarboxylic acid bishydrazides with dialkyl chloroethynyl phosphonate. This reaction represents a new approach to the synthesis of 1,3,4-oxadiazoles, and the process's efficiency was demonstrated. The resulting compounds were tested against a range of test cultures: Staphylococcus aureus ATCC6538; Pseudomonas aeruginosa 0387; and Candida utilis LIA-01. All synthesized compounds exhibited moderate antistaphylococcal activity and weak fungistatic action. The cytotoxicity and antiviral activity of the obtained compounds against the influenza A (H1N1) virus was studied in vitro . Two of seven compounds under investigation (28%) have demonstrated high anti-viral activity against influenza virus A/Puerto Rico/8/34 (H1N1) with selectivity indices of 15 and 24.