Microwave-assisted extraction (MAE) and microwave-assisted hydrolysis (MAAH) were developed for the sample preparation of guava leaves prior to GC determination of quercetin and its glycosides. Ethanol was selected as the solvent. The optimum MAE temperature, particle size, solvent volume and MAE time are 120 degrees C, 40 - 60 mesh, 20 mL and 5 min, respectively; the optimum MAAH temperature a...

Structural modification of the peptide backbone via N-methylation is a powerful tool to modulate the pharmacokinetic profile and biological activity of peptides. Here we describe a rapid and highly efficient microwave(MW)-assisted Fmoc/tBu solid-phase method to prepare short chain N-methyl-rich peptides, using Rink amide p-methylbenzhydrylamine (MBHA) resin as solid-phase support. This method p...

A practical method was elaborated for the synthesis of (aminomethylene)bisphosphine oxides comprising the catalyst- and solvent-free microwave-assisted three-component condensation of primary amines, triethyl orthoformate and two equivalents of diphenylphosphine oxide. The method is also suitable for the preparation of (aminomethylene)bisphosphonates using (MeO)2P(O)H/(MeO)3CH or (EtO)2P(O)H/(E...

Rutin was subjected to intermolecular transglycosylation assisted with microwave irradiation using cyclodextrin glucanotransferase (CGTase) produced from Bacillus sp. SK13.002. Compared with the conventional enzymatic method for rutin transglycosylation (without microwave irradiation), microwave-assisted reaction (MAR) was much faster and thus more efficient. While the conventional reaction too...

Microwave-assisted method has wide application in combinatorial chemistry. It become a powerful tool building the bioactive and pharmaceutical important compounds library within short time. In view of pronounced effect methods synthetic chemistry their importance drug discovery, systematic work on solvent-free synthesis 2,4-(IH,3H)Pyrimidinedione(uracil) was carried out. Comparison made between...

New derivatives of 7-hydroxy-4-methylcoumarin were synthesized using a chemical method and a microwave-assisted method to compare the feasibility, reaction times, and yields of the product. The newly synthesized coumarins were characterized by different spectroscopic techniques (FT-IR and NMR) and micro-elemental analysis (CHNS). In vitro antioxidant activities of these compounds were evaluated...

The extraction of compounds from Centella asiatica a member the family Apiaceae by adopting Ultrasound assisted Extraction (UAE), Microwave (MAE) and pre-treatment followed Microwave-assisted were reported. yield extract, phenol content, antioxidant activity Acetylcholine esterase found to be more in extract obtained method. is 30.8% UAE MAE methods. content 1289 ± 0.57 μg GAE/mL which 27% high...

Bee pollen is becoming an important product thanks to its nutritional properties, including a high content of bioactive compounds such as essential amino acids, antioxidants, and vitamins. Fresh bee pollen has a high water content (15%-30% wt %), thus it is a good substrate for microorganisms. Traditional conservation methods include drying in a hot air chamber and/or freezing. These techniques...

Microwave-assisted double decarboxylative Claisen rearrangement of bis(allyl) 2-tosylmalonates provides substituted 1,6-heptadienes, which may be alkylated, and then converted into pyridines by ozonolysis followed by reaction with ammonia generated in situ under microwave conditions.