Search

Porcine aortic tissue was decellularized by subcritical dimethyl ether (DME) used as an alternative to the surfactant sodium dodecyl sulfate. The process included three steps. For the first step, lipids were extracted from the porcine aorta using subcritical DME at 23 °C with a DME pressure of 0.56 MPa. Next, DME was evaporated from the aorta under atmospheric pressure and temperature. The second step involved DNA fragmentation by DNase, which was primarily identical to the common method. For the third step, similar to the common method, DNA fragments were removed by washing with water and ethanol. After 3 days of DNase treatment, the amount of DNA remaining in the porcine aorta was 40 ng/dry-mg, which was lower than the standard value of 50 ng/mg-dry. Hematoxylin and eosin staining showed that most cell nuclei were removed from the aorta. These results demonstrate that subcritical DME eliminates the need to utilize surfactants.

Liquefied dimethyl ether (DME) was employed as an antisolvent to crystallize glycine from its aqueous solution. The proposed method can be performed at 20–25 °C and has the potential to reduce the energy consumption of drying or crystallizing using ethanol. α-Glycine crystals were successfully obtained from glycine aqueous solutions by mixing in liquefied DME, which was easily removed from the crystals by decompression. Contact with a liquefied DME/water mixture and small γ-glycine crystals resulted in the α-glycine converting to γ-glycine. This was only observed for saturated glycine solutions. We speculated that this conversion occurs via a solution-mediated transition. Pure liquefied DME is not capable of promoting solvent-mediated transitions, so saturated glycine solutions treated with the pure antisolvent can give α-glycine as the sole product., Food science, Chemical engineering, Materials, Chemistry, Natural product, Amino acid, Crystallization, Antisolvent, Subcritical fluid.

The mangosteen (Garcinia mangostana Linn.) pericarp contains rich xanthone, a one kind of the polyphenols in the non-edible portion. In recent years, xanthones have been noted as a functionality such as anti-cancer effect and is expected as pharmaceuticals and health supplements. In this work, extraction of xanthones from mangosteen pericarp by using liquefied DME were investigated. Wet powder and cube samples were used as a raw material. Experimental conditions were 35 °C, 0.8 MPa with various amounts of sample (1, 3, 6 g). Extracted components were analyzed by using high performance liquid chromatography (HPLC). As a result, it was confirmed that eight kinds of xanthones such as alpha-mangostin, 3-Isomangostin, Mangostanol, 8-Desoxygartanin, Gartanin, Garcinone E, 9-Hydroxycalabaxanthone, beta-Mangostin were extracted. The highest yield of alpha-mangostin (42.9 mg/g_dry sample) was obtained with a powder sample of 6 g loaded. Final alpha-magostin corresponded to about 104% of the ethanol extraction with wet mangosteen pericarp, and 72% of the dried sample. Therefore, it was considered that in the extraction of xanthones from the mangosteen, liquefied DME extraction was valid.

Recently, a simple method for the extraction of lipids from wet biomass using liquefied dimethyl ether (DME) without drying, cell disruption, or heating was proposed. Here, the versatility of this method was evaluated for labyrinthula Aurantiochytrium limacinum (A. limacinum). The liquefied DME was passed through the extractor that filled by A. limacinum at different time intervals. The extraction of lipids from A. limacinum of moisture-rich microorganism was successfully achieved, the yield of lipid was 46.1 wt% of the dry weight of the sample. In comparison, the yields of lipid were 21.3 wt%, 43.6 wt% and 50.7 wt% when supercritical carbon dioxide (SCCO 2 ), hexane-Soxhlet and Bligh-Dyer (BD) extraction methods were applied as extractants, respectively. However, the drying and cell-disruption process were required in SCCO 2 , hexane-Soxhlet, and BD extraction methods.

Cell disruption is regarded as an indispensable pretreatment step before the extraction of microalgae with biomineralized cell walls. Here, two typical microalgae—diatom Chaetoceros gracilis (C. gracilis) and coccolithophore Pleurochrysis carterae (P. carterae)—covered by “hard” biomineralized cell walls were used as starting materials for lipid extraction using liquefied dimethyl ether (DME) without any pretreatment such as drying or cell disruption. The liquefied DME extraction experiments were performed at 25 °C and 0.59 MPa using a semi-continuous, flow-type system. The results of the yield, elemental composition, molecular weight distribution, fatty acid composition, and trace element composition indicated that the performance of liquefied DME extraction was similar to that of Bligh–Dyer extraction and better than that of hexane Soxhlet extraction, despite the latter two methods requiring pre-drying and cell disruption processes. It was also proven that the cell wall of microalgae would not affect lipid extraction of liquefied DME, thereby the liquefied DME extraction method is suitable for extracting lipids from microalgae with biomineralized cell walls. Besides, the lipids extracted by liquefied DME can be further used for biodiesel production.

Most of the residues after extracting juice from the citrus fruit are discarded, although they contain valuable substances such as flavonoids and essential oils. While most of the citrus flavonoids are present in the fruit peel, various valuable substances are also contained in the leaves. Moreover, the leaves and peels of citrus plants contain a large amount of moisture; hence, dewatering is essential for extracting valuable substances. Herein, we used liquefied dimethyl ether (DME) as the extractant for dewatering and extraction of valuable substances. With this process, >70% of the water from the wet samples was removed and valuable substances were isolated from the wet samples. The properties of the original and dewatered samples and the extract were evaluated using high-performance liquid chromatography. While the essential oils could be extracted, it was not possible to extract flavonoids by the liquefied DME method.