a simple and green chemical procedure was reported for the synthesis of dihydropyrimidinones from various aldehydes, ethyl acetoacetate and urea or thiourea using  holmium chloride as catalyst. the reactions were performed under solvent free conditions with ultrasound irradiation as the energy source. the advantages of this protocol include the excellent yield, operational simplicity, short tim...

Background and objectives: Colchicum kurdicum (Bornm.) Stef. is a flowering perennial monocotyledon plant that has many important bioactive compounds especially colchicine and colchicine derivatives. In this study, the ultrasound-assisted acidic-solvent extraction method coupled with response-surface method was presented as the successful method for large scale extract...

a simple, rapid and sensitive solvent assisted-dispersive solid phase extraction method was developed for the extraction of iron(ii) prior to its spectrophotometric determination. the fe(ii) reacted with 2,4,6-tris(2-pyridyl)-1,3,5-triazine, neutralized with sodium dodecyl sulfate and extracted onto the fine particles of benzophenone which were formed upon rapid injection of a mixture of benzop...

In the present study, ultrasound-assisted extraction of oil from rice bran was investigated through response surface methodology (RSM), where process variables were amplitude level (50–100%) and sonication time (5-30 min). It was found that all process variables had significant (p<0.05) effects on the response variable. A central composite design (CCD) was used to determine the optimum process ...

the genus haplophyllum, which belongs to the rutaceae family, includes 18 species in iran. in this study, after collecting plant material, botanical identification and suitable drying, the essential oils from aerial parts of haplophyllum robustum bge. were extracted by three different isolation techniques, conventional hydrodistillation (hd), microwave-assisted hydrodistillation (mahd) and solv...

Ultrasound-assisted extraction is evaluated as a simpler and more effective alternative to conventional extraction methods for the extraction of bioactive compounds from natural product. This study investigated the use of ultrasound-assisted extraction to extract three dibenzylbutyrolactone lignans, including tracheloside, hemislienoside, and arctiin from Hemistepta lyrata. Factors such as extr...

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...

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Ultrasound-assisted extraction (UAE) was evaluated as a simpler and more effective alternative to conventional extraction methods for the isolation of curcuminoids from turmeric plant rhizomes. The turmeric samples were extracted under indirect sonication in an ultrasonic bath, and compared with the conventional methods. It was found that the yield of ultrasound-assisted extraction was approxim...