Reactive Extraction of the Acylglycerides Present in Various Materials using Rhizopus oryzae Resting Cells

We carried out reactive extractions at moderate temperatures using Rhizopus oryzae resting cells and various solid materials containing different proportions of vegetable oil. Our methodology allows for free fatty acids and either methyl or solketal fatty esters to be prepared in moderate to high yields. Moreover, the process can be carried out in either a solvent or a solvent-free system. In a solvent-free system, the final yield can be increased if easily ground solid material is used. The water present in each material and the solvents used has an influence on the results.     

The extraction process optimization and physicochemical properties of polysaccharides from the roots of Euphorbia fischeriana

Response surface methodology (RSM) was used to determine the optimum extraction conditions for polysaccharides (EFP) from the roots of Euphorbia fischeriana. A Box-Behnken design (BBD) with four independent variables was investigated, such as extraction temperature (°C), water/solid ratio, extraction number (n), and extraction time (h). The results indicated optimum extraction conditions were extraction temperature of 97 °C, water/solid ratio of 9:1, extraction number of 2 and extraction time of 2.4 h, respectively. Under these conditions, the experimental value was 24.6 ± 0.62, which was well in close agreement with value predicted by the model. The preliminary chemical analysis of EFP revealed the EFP contained 25.43% polysaccharides, 20.42% uronic acids, 2.54% sulfate radical and 23.41% proteins. And the neutral polysaccharides were mainly composed of glucose, arabinose, rhamnose, galactose, xylose, mannose in the ratio of 21:8:5:3:1:1.     

High-throughput tissue extraction protocol for NMR- and MS-based metabolomics

In metabolomics, tissues typically are extracted by grinding in liquid nitrogen followed by the stepwise addition of solvents. This is time-consuming and difficult to automate, and the multiple steps can introduce variability. Here we optimize tissue extraction methods compatible with high-throughput, reproducible nuclear magnetic resonance (NMR) spectroscopy- and mass spectrometry (MS)-based metabolomics. Previously, we concluded that methanol/chloroform/water extraction is preferable for metabolomics, and we further optimized this here using fish liver and an automated Precellys 24 bead-based homogenizer, allowing rapid extraction of multiple samples without carryover. We compared three solvent addition strategies: stepwise, two-step, and all solvents simultaneously. Then we evaluated strategies for improved partitioning of metabolites between solvent phases, including the addition of extra water and different partition times. Polar extracts were analyzed by NMR and principal components analysis, and the two-step approach was preferable based on lipid partitioning, reproducibility, yield, and throughput. Longer partitioning or extra water increased yield and decreased lipids in the polar phase but caused metabolic decay in these extracts. Overall, we conclude that the two-step method with extra water provides good quality data but that the two-step method with 10 min partitioning provides a more accurate snapshot of the metabolome. Finally, when validating the two-step strategy using NMR and MS metabolomics, we showed that technical variability was considerably smaller than biological variability.     

Purification and Separation of A and B Forms of N-Acetyl-β-D-Hexosaminidase from Human Aorta

Human aorta has been shown to possess multiple forms of N-Acetyl-6-D-hexosaminidase (β-2-acetamido-2-deoxy-D-glucoside-acetamido-deoxyglucohydro-lase, EC 3.2, 1.30). The enzyme was separable, by gel electrophoresis, into 2 enzymatically active bands representing A and B forms. By gel electro-focussing, A and B forms were further subdivided into at least 5 and 8 bands, respectively. The B form consisted of 4 bands (B₁) and 4 bands (B₂), which were not inactivated at 50° for 3 hr. (at pH 4.4) in the presence of serum; whereas, the 5 bands found in A form were completely inactivated. All forms of the enzyme were active towards naphthol-AS-BI-N-acetyl-β-D-glucosaminide and the corresponding galactosaminide (about one-eighth of the hydrolysis rate of the former), suggesting each single enzyme acts on both substrates. The N-acetyl-hexosaminidases of bull epididymis, by comparison, were also found to be active towards both substrates and to possess 13 bands having pis more alkaline than those of the B form of the human enzyme, By heat inactivation we found that the aortic enzyme consisted of 51% of A and 49% of B (B₁ + B₂ .). Neuraminidase had no effect on either form of the aortic preparation. Both forms were partially purified and separated by conventional methods. They required BSA for their maximal activity; the A form being more dependent BSA than the B form, With PNP-N-acetyl-β-D-glucosaminide and the corresponding galactosaminide, Km of 1.04 mH and 0.54 mM, respectively, for A form and of 1.74 and 1.48 mM, respectively, for B form were obtained. While the purified B form was stable and did not transform into other species, the purified A form gradually transformed into B form as well as into other new forms during storage at -20°.     

Potato tuber proteomics: comparison of two complementary extraction methods designed for 2-DE of acidic proteins

Two protein extraction procedures were tested in order to remove interfering compounds prior to 2-DE of potato tubers. These methods using SDS lysis buffer and phenol-phase extraction were compared regarding the quality of the resulting 2-D gel. While the resolution of SDS extracts on semipreparative gels seems better, both methods lead to similar extraction yields and total number of spots. The procedures are complementary regarding the Mr range of preferentially extracted proteins.     

莲黄酮类化合物鉴定、功能与应用的研究进展

莲（Nelumbo）是一种重要的水生经济作物,富含黄酮、生物碱、多糖等生物活性物质,可药食两用。目前在莲中已经鉴定出超过百种的黄酮类化合物,包括芦丁、槲皮素、金丝桃苷等,这些物质具有抑菌抗炎、降脂减肥、抗氧化等多种药用功效。本文介绍了莲黄酮类化合物的种类,以及包括大孔树脂色谱法和高效液相色谱-质谱联用法在内的提取与鉴定方法,并对莲黄酮类化合物的功能活性、功能产品开发及其在疾病治疗中的最新应用进行了系统总结,以期为莲黄酮类化合物的科学研究和综合利用提供参考。     

无花果果皮中花青素的提取工艺的建立

本研究使用单因素方法考察了无花果(Ficus carica L.)果皮中花青素的最佳提取条件,并考察了7种参数对花青素提取率的影响。参数设置如下:溶剂性质(水,甲醇,乙醇和丙酮)、提取次数(1~3次)、固液比(1/50,1/100,1/150和1/200)、提取时间(60 min,120 min,180 min和240 min)、甲醇浓度(0,20%,40%,60%,80%和100%)、酸类型(盐酸,乙酸,柠檬酸和酒石酸)和酸浓度(0,1%,2%,5%和10%)。使用pH-示差法测量无花果果皮中单体花色素的含量。研究显示,无花果果皮中花青素的最佳提取条件为:溶剂为甲醇溶剂,提取次数为2次,固液比为1/100,提取时间为180 min,甲醇浓度为80%,酸类型为柠檬酸,柠檬酸浓度为5%。该最佳提取条件下的花青素的提取率达到最高(345.62 mg/100g DS)。     

响应面法优化飞龙掌血中总生物碱的提取工艺

以飞龙掌血（Toddalia asiatica（L.）Lam.）的根为实验材料,以总生物碱的含量为检测指标,应用响应面法对飞龙掌血中总生物碱的提取工艺进行了优化。结果显示,当提取条件为乙醇体积分数74.76%、料液比20∶1和提取时间32.87 min时,飞龙掌血提取物中总生物碱的理论含量值可达11.09 mg/g,总生物碱含量达到最高值。按照最佳提取工艺条件进行验证,3次平行实验的均值为（10.74 ±0.18）mg/g,与理论值差异较小,表明利用响应面法来优化飞龙掌血中总生物碱的最佳提取工艺模型拟合良好,具有一定实用价值。