Optimization of microwave-assisted extraction for alizarin and purpurin in Rubiaceae plants and its comparison with conventional extraction methods

2005 ◽  
Vol 28 (4) ◽  
pp. 387-396 ◽  
Author(s):  
Minoo Dabiri ◽  
Shabnam Salimi ◽  
Alireza Ghassempour ◽  
Ali Rassouli ◽  
Mohammad Talebi
2011 ◽  
Vol 236-238 ◽  
pp. 309-312
Author(s):  
Na Li ◽  
Yong Qiang Mao

A simple and rapid microwave assisted extraction (MAE) technique for the extraction of flavonoids from the leaves of Syringa oblatewas developed. The influence of several extraction variabes on extraction yield of flavonoids were discussed. The optimum extraction conditions obtained were: 50% ethanol solution, 480 W microwave power, 6 min extraction time and 20:1 (mL/g) as the ratio of solvent volume to sample weight. Compared with conventional extraction methods, MAE is an efficient and rapid method for the extraction of the flavonoids from the leaves of Syringa oblate.


2012 ◽  
Vol 518-523 ◽  
pp. 430-435 ◽  
Author(s):  
Hai Rong Guo ◽  
Shao Ying Ma ◽  
Xiao Fei Wang ◽  
Er Fang Ren ◽  
Yuan Yuan Li

Microwave-assisted extraction (MAE) was used to extract chlorophylls from filter mud. Ethanol was used as the solvent. The optimal conditions for the MAE of chlorophylls were concluded from the study as the irradiation time, 50 s, the ratio of liquid to solid, 8:1 (mL/g), the extraction temperature, 40 °C, and the extraction time, 60 min. Compared with conventional extraction, the MAE of chlorophylls from the filter mud was more effective. The extraction time for MAE was 60 min with 0.277 mg/g chlorophyll yield, while conventional extraction needed 240 min with only about 0.259 mg/g chlorophyll yield. The Ultraviolet Absorption Spectra of the extracted chlorophylls showed that there was a strong absorption peak at about 663 nm. C=N, Mg-N and C-N was not seen existed from the infrared spectroscopy probably because that the mixed extracts were not purified and the chlorophyll content was less.


2008 ◽  
Vol 91 (1) ◽  
pp. 174-180 ◽  
Author(s):  
Mercedes Barriada-Pereira ◽  
Iván Iglesias-García ◽  
María J Gonzlez-Castro ◽  
Soledad Muniategui-Lorenzo ◽  
Purificación López-Maha ◽  
...  

Abstract This paper describes a comparative study of 2 extraction methods, pressurized liquid extraction (PLE) and microwave-assisted extraction (MAE), for the determination of organochlorine pesticides (OCPs) in fish muscle samples. In both cases, samples were extracted with hexaneacetone (50 + 50), and the extracts were purified by solid-phase extraction using a carbon cartridge as the adsorbent. Pesticides were eluted with hexaneethyl acetate (80 + 20) and determined by gas chromatography with electron-capture detection. Both methods demonstrated good linearity over the range studied (0.0050.100 g/mL). Detection limits ranged from 0.029 to 0.295 mg/kg for PLE and from 0.003 to 0.054 mg/kg for MAE. For most of the pesticides, analytical recoveries with both methods were between 80 and 120, and the relative standard deviations were <10. The proposed methods were shown to be powerful techniques for the extraction of OCPs from fish muscle samples. Although good recovery rates were obtained with both extraction methods, MAE provided advantages with regard to sample handling, cost, analysis time, and solvent consumption. Acceptable validation parameters were obtained although MAE was shown to be more sensitive than PLE.


Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 559
Author(s):  
Sónia J. Amarante ◽  
Marcelo D. Catarino ◽  
Catarina Marçal ◽  
Artur M. S. Silva ◽  
Rita Ferreira ◽  
...  

Microwave-assisted extraction (MAE) was carried out to maximize the extraction of phlorotannins from Fucus vesiculosus using a hydroethanolic mixture as a solvent, as an alternative to the conventional method with a hydroacetonic mixture. Optimal MAE conditions were set as ethanol concentration of 57% (v/v), temperature of 75 °C, and time of 5 min, which allowed a similar recovery of phlorotannins from the macroalgae compared to the conventional extraction. While the phlorotannins richness of the conventional extract was slightly superior to that of MAE (11.1 ± 1.3 vs. 9.8 ± 1.8 mg PGE/g DWextract), both extracts presented identical phlorotannins constituents, which included, among others, tetrafucol, pentafucol, hexafucol, and heptafucol structures. In addition, MAE showed a moderate capacity to scavenge ABTS•+ (IC50 of 96.0 ± 3.4 µg/mL) and to inhibit the activity of xanthine oxidase (IC50 of 23.1 ± 3.4 µg/mL) and a superior ability to control the activity of the key metabolic enzyme α-glucosidase compared to the pharmaceutical drug acarbose.


Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 456 ◽  
Author(s):  
Ding-Tao Wu ◽  
Wen Liu ◽  
Mei-Lin Xian ◽  
Gang Du ◽  
Xin Liu ◽  
...  

Seven extraction methods, including hot water extraction (HWE), pressurized water extraction (PWE), ultrasound-assisted extraction, microwave-assisted extraction, ultrasound-assisted enzymatic extraction, high-speed shearing homogenization extraction, and ultrasound-microwave-assisted extraction, were utilized to extract polyphenolic-protein-polysaccharide complexes (PPPs) from Hovenia dulcis. Next, their physicochemical properties and in vitro antioxidant activities, antiglycation effects, and inhibition activities on α-glucosidase and α-amylase were studied and compared. The findings from this study indicate that various extraction processes exhibit notable influences on the physicochemical properties and in vitro bioactivities of PPPs. Extraction yields, contents of polyphenolics and flavonoids, apparent viscosities, molecular weights, molar ratios of monosaccharide compositions, and ratios of amino acid compositions in PPPs varied in different extraction methods. Furthermore, 13 phenolic compounds in PPPs, including rutin, myricitrin, myricetin, quercetin, kaempferol, protocatechuic acid, gallocatechin, p-hydroxybenzoic acid, ampelopsin, quercetin-7,4′-diglucoside, dihydroquercetin, 5-methylmyricetin, and naringenin, were identified. The relatively strong in vitro antioxidant activities, antiglycation effects, and inhibition activities on α-glucosidase and α-amylase were determined in both PPP-W and PPP-P obtained by HWE and PWE, respectively. The high content of total polyphenolics may be one of the main contributors to their in vitro bioactivities. The findings have shown that the PWE method can be an appropriate method to prepare PPPs with strong bioactivities for application in the functional food industry.


2020 ◽  
Vol 19 (2) ◽  
pp. 110 ◽  
Author(s):  
Robby Gus Mahardika ◽  
Occa Roanisca

Tristaniopsis merguensis Griff. is a species of the Myrtaceae family and has been widely used by people of Bangka Belitung as a traditional medicine to reduce cholesterol, gastric pains, and improve cardiac performance. Extraction methods are the crucial efficacy of herbal medicine. The conventional method, like maceration, takes a long time. In this study, the leaves of Tristaniopsis merguensis were extracted using Microwave-Assisted Extraction (MAE) to reduce extraction time. The extraction using MARS (Microwave Accelerated Reaction System) 6 by CEM Corporation with time variation times of 5, 10, 15, 30 min with temperature of 60, 80, 100oC at 1200 W. The yield using acetone extraction of Tristaniopsis merguensis leaves increases with time and temperature. The extraction dependent on solvent extraction, polar solvent like ethanol, and methanol were higher than semi-polar solvents like acetone and ethyl acetate. The polyphenol content of acetone extract using MAE (10 min, 80oC) was found to be 234.67 mg Gallic Acid Equivalent per gram (GAE/g); it was higher than acetone extract using maceration. The phytochemical results show there are no difference in the active compound using MAE and maceration, i.e. alkaloids, tannin, and flavonoids. Yield extraction, time, and phytochemical results of MAE are more favorable than a maceration.


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