Synthesis and antitumor activities of novel Mannich base derivatives derived from natural flavonoids

In our current study, a series of reactions with isolated natural flavonoids (2-phenylchromen-4-one) and flavanone (2,3-dihydro-2-phenylchromen-4-one) through Mannich base was carried out by a one-pot three-component reaction. Their structure-activity relationship study (SAR) reveals the anticancer activity of natural compounds and their Mannich bases. The flavones were substituted by imine at position C-8, while in the flavanones, the reaction takes place at positions C-8 and C-3. Spectroscopic techniques characterized all the isolated and newly synthesized derivatives. Anticancer activity was checked on HeLa and MCF-7 (cancer cell lines) and BHK-21 (normal cell line). Using propidium iodide (PI) and DAPI staining as fluorescence microscopic imaging was confirmed the Apoptotic effect of potent compound. Further, it was evaluated by cell cycle analysis through flow-cytometry, reactive oxygen species and lactate dehydrogenase production. The caspase-9 and -3 activity were estimated by mitochondrial membrane potential. Derivative of naringenin, ((2S)-4′,5,7-Trihydroxyflavan-4-one) where reactions occur at position C-3 were active than others.

SYNTHESIS, BIOLOGICAL STUDY, DNA INTERACTION OF MANNICH BASE METAL COMPLEXES DERIVED FROM BENZAMIDE

Objective: Coordination compounds occur widely in nature and they comprise a large share of current inorganic research. The Mannich reaction is a classic method for the preparation of Mannich bases, namely, β amino compounds, which are heterocyclic. Methods: A novel Mannich base of N-((3,4-dimethoxyphenyl)(2,5-dioxopyrrolidin-1-yl) methyl)benzamide and its coordination complexes with transition metals Mn and Co have been synthesized and characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, UV-Visible, IR, NMR, and Mass spectral studies. Results: Based on the magnetic moment and UV-Visible spectral data, octahedral geometries were assigned for the metal complexes. The metal complexes were screened for antifungal activity. Conclusion: the metal complexes have shown good activity than the ligand. The binding of selected metal complexes with calf thymus DNA was investigated. It is found that the cobalt (II) metal complex of the ligand showed efficient DNA binding ability.

Mannich Base as an Efficient Corrosion Inhibitor of AA6061 in 0.5 M HCl: Electrochemical, Surface Morphological and Theoretical Investigations

The inhibition action of a Mannich base, N-(1- morpholinobenzyl) semicarbazide (MBS), was examined on AA6061 corrosion in 0.5 M HCl solution at varied temperatures (303 to 323 K). The testing was performed by potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. The inhibition performance of MBS was improved with an increment in its concentration (0.01–2.56 mM) and temperature rise (303 to 323 K). MBS showed a mixed inhibitor behavior at all concentrations and temperatures range studied. MBS displayed the highest inhibition efficiency of 98% at 2.56 mM and 323 K. Inhibitor followed mixed adsorption on the alloy surface and obeyed the Langmuir isotherm model. The results obtained from the EIS were in good agreement with that of the PDP results. An appropriate mechanism was proposed for the corrosion inhibition of AA6061. Inhibitor molecules adsorption on alloy surface was confirmed by surface morphology testing by a scanning electron microscope (SEM) and atomic force microscope (AFM). Theoretical studies using density-functional theory (DFT) confirmed the experimental results.

Preparation and assistant-dyeing of formaldehyde-free amphoteric acrylic retanning agent

With the enhancement of environmental protection consciousness, concerns have been raised about non-toxic and biodegradable leather retanning agents. According to the European standard 2002/231/EC, the free formaldehyde content of leather products should be less than 150 mg/kg. As one of the retanning agents in the market, the content of free formaldehyde in the Multifunctional retanning agent (MTA) is 372.22 mg/kg and higher than the limit value. In this work, glutaraldehyde as an alternative of formaldehyde was used to modify acrylic polymer and an amphoteric acrylic retanning agent was prepared. Then it was used in retanning process, and its retanning and assistant-dyeing properties were investigated. The results showed that the free formaldehyde content of amphoteric acrylic retanning agent modified with glutaraldehyde was only 4.17 mg/kg. Meanwhile, the presence of amino groups in the amphoteric acrylic retanning agent improved the dyeing properties of leather by electrostatic attraction. Compared with the leather treated with anionic acrylic retanning agent, the residual dye concentration of the dyeing effluent of the retanned leather with amphoteric acrylic retanning agent decreased from 17.4 mg/L to 10.0 mg/L, and the dyed leather had better resistances to friction and water-washing. In addition, the BOD5/COD value of the wastewater after Mannich base polymer retanning was only 0.32, indicating that the retanning agent was biodegradable. Moreover, the leather retanned with amphoteric acrylic retanning agent had good thermal stability, fullness and physical and mechanical properties. Graphical abstract