Efficient microwave assisted synthesis of novel 1,2,3-triazole–sucrose derivatives by cycloaddition reaction of sucrose azides and terminal alkynes

Recent Advances in Microwave-Assisted Copper-Catalyzed Cross-Coupling Reactions

Cross-coupling reactions furnishing carbon–carbon (C–C) and carbon–heteroatom (C–X) bond is one of the most challenging tasks in organic syntheses. The early developed reaction protocols by Ullmann, Ullman–Goldberg, Cadiot–Chodkiewicz, Castro–Stephens, and Corey–House, utilizing elemental copper or its salts as catalyst have, for decades, attracted and inspired scientists. However, these reactions were suffering from the range of functional groups tolerated as well as severely restricted by the harsh reaction conditions often required high temperatures (150–200 °C) for extended reaction time. Enormous efforts have been paid to develop and achieve more sustainable reaction conditions by applying the microwave irradiation. The use of controlled microwave heating dramatically reduces the time required and therefore resulting in increase in the yield as well as the efficiency of the reaction. This review is mainly focuses on the recent advances and applications of copper catalyzed cross-coupling generation of carbon–carbon and carbon–heteroatom bond under microwave technology.

Synthesis, biological evaluation and molecular dynamics studies of 1,2,4-triazole clubbed Mannich bases

The present work highlightsthe synthesis of a newer biologically active Mannich bases contributing 4-((4-fluorobenzylidene)amino)-5-(pyridin-4-yl)-4H-1,2,4-triazole-3-thiol and various heterocyclic amines via N-Mannich reaction by the conventional method as well as microwave heating approach as a part of an environmentally benign synthetic protocol. All the synthesized compounds were characterized by spectral analysis and were screened for in vitro antimicrobial, antitubercular and antiprotozoal activity. The compound 4k was found to be most active respectively against S. aureus (MIC 12.5 μM) and C. albicans (MIC 100 μM). The derivative 4 g displayed potency against L.mexicana and T. cruzi with IC₅₀ value 1.01 and 3.33 μM better than reference drug Miltefosina and Nifurtimox. The compound 4b displayed excellent potency against M. tuberculosis (MIC 6.25 μM) in the primary screening. The computational studies revealed for that Mannich derivative (4b) showed a high affinity toward the active site of enzyme which provides a strong platform for new structure-based design efforts. The Lipinski's parameters showed good drug-likeness properties and can be developed as an oral drug candidate.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2013-2014

This review is the eighth update of the original article published in 1999 on the application of Matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2014. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly- saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 37:353-491, 2018.

Antifungal activity of 1'-homo-N-1,2,3-triazol-bicyclic carbonucleosides: A novel type of compound afforded by azide-enolate (3+2) cycloaddition

The first report of 1'-homo-N-1,2,3-triazol-bicyclic carbonucleosides (7a and 7b) is described herein. Azide-enolate (3+2) cycloaddition afforded the synthesis of this novel type of compound. Antifungal activity was evaluated in vitro against four filamentous fungi (Aspergillus fumigatus, Trichosporon cutaneum, Rhizopus oryzae and Mucor hiemalis) as well as nine species of Candida spp. as yeast specimens. These pre-clinical studies suggest that compounds 7a and 7b are promising candidates for complementary biological studies due to their good activity against Candida spp.

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 non-tumor liver cells. The above mentioned derivatives represent promising leads for the development of new generation of sugar-triazole antifungal agents.