With an intention to synergize the anti-bacterial activity of chalcones and rhodanine-3-acetic acid, several hybrid compounds possessing chalcone and rhodanine-3-acetic acid moieties were synthesized and tested for their anti-bacterial activity. Some compounds presented great anti-microbial activities against Gram-positive bacteria (including the multidrug-resistant clinical isolates). This class of
Photoredox-Catalyzed Cyclopropanation of Michael Acceptors
作者:Ana M. del Hoyo、Marcos García Suero
DOI:10.1002/ejoc.201601604
日期:2017.4.18
A new protocol for the catalytic cyclopropanation of α,β-unsaturated carbonyl compounds with diiodomethane by means of photoredox catalysis has been successfully developed. The transformation is characterized by its mild conditions, functional group compatibility, and excellent selectivity profile.
Following our previously reported Prins cyclization strategy, a series of novel and highly functionalized flavonoid based THPs (Prins products) were designed, synthesized and evaluated for their anti-proliferative activity. Novel products were afforded in excellent yields (72-96%) within 20-90 min at 62 degrees C using flavonoid aldehydes, homoallylic alcohols, p-TSA center dot H2O (catalyst and reagent) and MS 4 angstrom in CHCl3. Deprotection of tosyl group was achieved with TFA (catalyst and solvent) at 140 degrees C to obtain 4-hydroxytetrahydropyrans and further reaction of 4-hydroxytetrahydropyrans with cinnamoyl chloride afforded 4-cinnamate tetrahydropyrans under neat condition. Synthesized compounds evaluated against human cancer cell lines (Hep3 beta, MCF-7 and Hela), have shown moderate to good antiproliferative activity in vivo. Compounds 3q and 3zb exhibited similar cytotoxicity (IC50 6.6 +/- 1.4, 6.9 +/- 1.0 mu M, respectively) to the reference drug doxorubicin (IC50 7.6 +/- 0.9 mu M) against the MCF-7 cancer cell line. Compound 3zb was found equally active as the standard drug (IC50 4.48 +/- 2.1 mu M) against the Hep3 beta cell line and compounds 3c and 3q showed moderate cytotoxicity (IC50 10.40 +/- 1.1, 12.9 +/- 1.7 mu M, respectively) against the HeLa cell line. (C) 2014 Elsevier Masson SAS. All rights reserved.
Synthesis and antimicrobial evaluation of l-phenylalanine-derived C5-substituted rhodanine and chalcone derivatives containing thiobarbituric acid or 2-thioxo-4-thiazolidinone
Four novel series of compounds, including the L-phenylalanine-derived C5-substituted rhodanine (6a-q, 7a-j) and chalcone derivatives containing thiobarbituric acid or 2-thioxo-4-thiazolidinone (9a-e, 11a-e) have been designed, synthesized, characterized, and evaluated for their antibacterial activity. Some of these compounds showed significant antibacterial activity against Gram-positive bacterias, especially against the strains of multidrug-resistant clinical isolates, among which compounds 6c-e, 6g, 6i, 6j and 6q exhibiting high levels of antimicrobial activity against Staphylococcus aureus RN4220 with minimum inhibitory concentration (MIC) values of 2 mu g/mL. Compound 6q showed the most potent activity of all of the compounds against all of the test multidrug-resistant clinical isolates tested. Unfortunately, however, none of the compounds were active against Gram-negative bacteria at 64 mu g/mL. (C) 2012 Elsevier Masson SAS. All rights reserved.