Synthesis of Novel Bivalent Hydrazino-Thymohydroquinone Analogs Derived from Thymoquinone as Potential Antimicrobial Agents

In our previous work, it was reported that thymoquinone (TQ) and some thymohydroquinone (THQ) derivatives were used as precursors for the synthesis of potential anticancer agents. Hence, as a part of our ongoing program in the design of biologically active compounds derived from TQ scaffold we herein investigated the synthesis of homo-and heteronuclear thymol dimers tethered through various linkers such as ethylene, butylene, acetyl and N,N'-acetyl piperazine groups. The newly prepared compounds were examined as antimicrobial agents. Compounds 7 and 8 bearing a piperazine moiety exhibited highest antibacterial activity comparing to TQ, THQ and ampicillin especially against Staphylococcus aureus bacteria with MIC value of 16 mu g/mL. All compounds showed moderate antifungal activity against Candida albicans and Aspergillus fumigatus. Together, the new TQ-based bivalent lead might be serving as a promising scaffold for development of novel and potent antimicrobial agents.