Novel π-Extended Quinazoline-Ferrocene Conjugates: Synthesis, Structure, and Redox Behavior

Novel ferrocene conjugates of tricyclic quinazoline derivatives are prepared by condensation of active C-6 methylene groups of mackinazolinones with ferrocenecarbaldehyde. Following this route the conjugated parent alkaloid as well as derivatives with nitro, amino, and alkanoylamino groups at C-2 were attached at the ferrocene moiety, thereby significantly extending the delocalized π system. In addition, the parent compound was subjected to the reaction with ferrocene-1,1'-dicarbaldehyde, giving rise to the symmetrical and unsymmetrical double condensation products – 1,1'-disubstituted ferrocene derivatives, which bear two alkaloid substituents. Some of the compounds obtained were subjected to X-ray crystallographic analyses. The influence of the substituents at C-2 through the extended conjugated π system on the iron atom is reflected by results of cyclovoltammetric measurements

Antimicrobial and cytotoxic activities of 1,2,3-triazole-sucrose derivatives

A library of 1-(1′,2,3,3′,4,4′,6-hepta-O-acetyl-6′-deoxy-sucros-6′-yl)-1,2,3-triazoles have been investigated for their antibacterial, antifungal and cytotoxic activities. Most of the target compounds showed good inhibitory activity against a variety of clinically and food contaminant important microbial pathogens. In particular, 1-(1′,2,3,3′,4,4′,6-hepta-O-acetyl-6′-deoxy-sucros-6′-yl)-4-(4-pentylphenyl)-1,2,3- triazole (5) was highly active against all the tested bacteria with minimal inhibitory concentrations (MICs) ranging between 1.1 and 4.4 μM and bactericidal concentrations (MBCs) from 2.2 and 8.4 μM. The compound 1-(1′,2,3,3′,4,4′,6-hepta-O-acetyl-6′-deoxy-sucros-6′-yl)-4-(4-bromophenyl)-1,2,3-triazole (3) showed antifungal activity with MICs from 0.6 to 4.8 μM and minimal fungicidal concentrations (MFCs) ranging between 1.2 and 8.9 μM. Furthermore, some of the compounds possessed moderate cytotoxicity against human breast, lung, cervical and hepatocellular carcinoma cell lines, without showing toxicity for nontumor liver cells. The above mentioned derivatives represent promising leads for the development of new generation of sugar-triazole anti fungal agents.This work has been supported by Fundação para a Ciência e a Tecnologia through grant Nos. PEst-C/EQB/LA0006/2013 and PEst-OE/AGR/UI0690/2014. T.M. Potewar and R.C. Calhelha are grateful to Fundação para a Ciência e a Tecnologia for their pos-doctoral Grant Nos. SFRH/ BPD/65173/2009 and SFRH/BPD/68344/2010, respectively. The authors thank to Serbian Ministry of Education, Science and Technological Development for financial support (grant number 173032). The NMR spectrometers are part of The National NMR Facility, supported by Fundação para a Ciência e a Tecnologia (RECI/BBB-BQB/0230/2012)