Synthesis and Biological Activity Evaluation of Polyfunctionalized Anthraquinonehydrazones

Background: Anthraquinone derivatives, frequently occurring motifs in many various natural compounds, have attracted a great deal of interest as compounds with a wide spectrum of biological activities. Introduction: The hybrid pharmacophore approach has become an object of considerable interest due to the incorporation of a five- or six-membered heterocyclic rings in the structure of various natural compounds, especially anthraquinone derivatives. Methods: A series of polyfunctionalized anthraquinonehydrazones have been synthesized via the azo-coupling reaction between anthraquinone-based triazenes and methylene active compounds. The structures of synthesized compounds were confirmed by spectral data. Some of the synthesized compounds were screened for their in vitro anticancer activity according to US NCI protocols. The screening of antimicrobial and antifungal activities against Candida albicans and Lactobacillus sp. was carried out. The synthesized compounds were evaluated for their antioxidant (DPPH free radical scavenging assay) and herbicidal activity. Results: The synthesized 1-[N'-(5-oxo-2-thioxoimidazolidin-4-ylidene)-hydrazino]-anthraquinone 1.5 displayed a high level of antimitotic activity against tested human tumor cells with mean GI50/TGI values 4.06/78.52μM. The screening of antimicrobial and antifungal activities led to the identification of 1.8 and 1.9 with a moderate effect on Candida albicans and Lactobacillus sp. Antioxidant activity evaluation allowed the identification of 1-[N'-(3-methyl-5-oxo-1-phenyl-1,5- dihydropyrazol-4-ylidene)-hydrazino]-anthraquinone 1.8 with an IC50 value of 3.715 mM. The herbicidal activity screening led to compound identification 1.8 with growth inhibition of Agrostis stolonifera at 25 %. Conclusion: The obtained anthraquinonehydrazones constitute an interesting template for the design of new synthetic agents with polypharmacological activities.