Synthesis and biological evaluation of benzamides and benzamidines: structural requirement of a pyrimidine ring for inhibition of EGFR tyrosine kinase

Synthesis of Evodileptin B, a Natural Anthranilate Derivative Isolated from Evodia lepta, and Evaluation of Its Therapeutic Potential against Parkinson's Disease

Evodileptin B (1) is a natural anthranilate derivative isolated from the ethanol extract of the aerial parts of Evodia lepta (Spreng.) Merr., a traditional medicinal plant of the family Rutaceae. We readily synthesized 1 via the amidation of phloretic with methyl anthranilate and evaluate its neuroprotective activity using a C. elegans Parkinson's disease (PD) model. The results showed that evodilpetin B ameliorated MPP⁺ -induced dopaminergic (DA) neurodegeneration in a dose-dependent manner. Evodileptin B treatment also significantly improved the DA neurotransmission-related behavioral defects such as reduced locomotory and food-sensing ability of worms under MPP⁺ exposure conditions, suggesting its potential application for the functional restoration of DA neurons. In addition, we found that 1 has an ability to regulate aggregation of α-synuclein by increasing proteasome activity in the human α-synuclein-expressing mutant worms. These results demonstrate that evodileptin B has strong neuroprotective properties and may be useful in the treatment of PD.

Synthesis and evaluation of arylamidine derivatives for new antimicrobial and cytotoxic activities

A series of arylamidines 3a-j was designed, synthesized and investigated for antimicrobial activity. Structures of the compounds were confirmed by IR, 1H-NMR and 13C-NMR and a 2D spectroscopic study was performed. A preliminary screening of the antimicrobial tests clearly showed that three out of ten arylamidines, viz, 3f, 3g and 3i, were effective against all the gram-negative bacteria: Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella enteric; and against the yeast, candida albicans. Further, the Minimum Inhibitory Concentrations (MIC) against the bacteria and yeast were determined. All compounds 3a-d, 3f, 3g, 3i and 3j were also investigated for their low cytotoxic effects on tested cell lines. Compounds 3d and 3f were the most effective derivatives against HL-60 and HEp-2 cells, respectively, with IC50 value (2µg/mL), and low normal cells toxicity.

N–H⋯π induced configurational isomerism and the role of temperature in the Z to E isomerization of 2-fluoro-N′-(3-fluorophenyl)benzimidamide

The role of temperature in polymorphism and the isolation of configurational isomers of 2-fluoro-N′-(3-fluorophenyl)benzimidamide have been investigated.

Synthesis and biological evaluation of benzamides and benzamidines as selective inhibitors of VEGFR tyrosine kinases

A series of benzamidines and benzamides was synthesized as selective inhibitors of vascular endothelial growth factor receptor (VEGFR) tyrosine kinases, and tested for inhibitory activity toward autophosphorylation by the enzyme assay. Selective inhibition of VEGFR-2 tyrosine kinase was observed in the salicylic amide 4e and the anthranilic amidine 5a, and their percent inhibitions of VEGFR-2 tyrosine kinase were 44-60% at a 10 microM concentration of compounds. The salicylic amide 4a showed inhibition of both VEGFR-1 and VEGFR-2 tyrosine kinases at a 10 microM concentration.

Benzamides and benzamidines as specific inhibitors of epidermal growth factor receptor and v-Src protein tyrosine kinases

The benzamides 1 and the benzamidines 2 as well as the cyclic benzamidines 3 were designed and synthesized as the mimics of 4-anilinoquinazolines for an inhibitor of EGFR tyrosine kinase. The specific inhibitions of EGFR tyrosine kinase were observed in the benzamides 1c and 1d, and the benzamidine 2a, whereas the specific inhibitions of v-Src kinase were observed in the benzamide 1j and the benzamidine 2d at a 10microg/mL concentration of compounds. The cyclic benzamidines 3a and 3b showed potent kinase inhibition of EGFR at a 1.0microg/mL concentration. According to the docking simulation using the X-ray structure of EGFR kinase domain in complex with erlotinib, the LigScore2 scoring function value of erlotinib was calculated as 5.61, whereas that of the benzamide 1c was 5.05. In a similar manner, the LigScore2 value of the cyclic benzamidine 3a was calculated as 5.10.