Biologically Active New N, N', N''-Tri-Substituted Ferrocenyl Phenylguanidines and their Characterization.

BACKGROUND: Introducing new candidates for various biological targets is a prime characteristic of the present day medicinal research and development. Guanidines are the important bioactive compounds and are well recognized for their diverse biological activities, especially as anticancer, antimicrobial and antioxidant agents. Due to the favorable electronic properties of ferrocene like lipophilicity, redox activity, stability in solution state and its easy derivatization, have made ferrocenyl compounds very popular molecules for biological uses. OBJECTIVES: Keeping in sight, it is valuable to synthesize ferrocenyl guanidines to increase the binding potency with DNA, make them redox active and more lipophilic compounds. METHODS: Six new ferrocenyl phenylguanidines (F1 - F6) have been synthesized via multi step protocol. The structures of F1 - F6 were established by using elemental analysis, UV-visible, multinuclear (1H and 13C) NMR and FTIR spectroscopy. Solution phase redox behavior, of the synthesized compounds, has been characterized by cyclic voltammetry. Two compounds (F2 & F4) were characterized by single crystal XRD. RESULTS: Due to the biological importance of guanidines; these ferrocenyl guanidiens were screened for different biological activities like antibacterial, antifungal, antioxidant and DNA binding. DNA interaction study was done by using UV-visible spectrometry and cyclic voltammetry revealed good binding capacity of the test compounds. CONCLUSION: The results revealed that the ferrocene incorporation to guanidines enhances their DNA binding ability. A similar trend was found in antioxidant and antimicrobial studies. Being the bioactive molecules these compounds are potential drug candidates.

Preliminary investigation of anticancer activity by determining the DNA binding and antioxidant potency of new ferrocene incorporated N,N',N″-trisubstituted phenylguanidines.

Six new bioactive ferrocene based phenylguanidines were successively synthesized and characterized by means of various analytical techniques like elemental analysis, FT-IR, multinuclear ((1)H and (13)C) NMR, UV-Vis spectroscopy and cyclic voltammetry. The interaction of compounds with DNA was investigated by spectroscopic and cyclic voltammetric measurements. The interaction was found to be the electrostatic and the binding constants values were impressively larger. Compounds f-1, f-2, f-3 have slight larger binding constant values ranging from 0.8×10(5) to 2.4×10(5) as compared to g-1, g-2 and g-3 ranging from 7.6×10(4) to 1.1×10(5) which is most probably due to the presence of ferrocene at para position where the delocalization of electrons is maximum. Antioxidant activity was determined by UV-Vis spectrophotometer by using DPPH as a free radical. All the compounds exhibit good antioxidant activity and the results so obtained support the structure activity relationship.