Original extract

To obtain the benzoic acid, add an excess of concentrated hydrochloric acid carefully with stirring to the aqueous alkaline solution remaining from the original extraction. When no further precipitation of benzoic acid occurs, cool the solution (if perceptibly warm) in ice-water, and then filter at the pump. Wash the benzoic acid thoroughly with cold water, drain, and then recrystallise from a large volume of boiling water. Benzoic acid is obtained as colourless crystals, m.p, 121° yield, 19-20 g. 

Anticancer drugs originally extracted from the cortex of Taxus brevifolia or Taxus baccata. They block cell division by inhibiting tubulin depolymerization. Two... 

Thanks are due to Dr. K. Nakanishi for his generous gift of PbTx and to Dr. R. Bagnis and A.M. Legrand for providing the original extracts which served in the purification of CTx. 

Advances in technology may make the best-appearing process obsolete before the plant can be put into operation. This happened to a multimillion dollar plant that Armour Company built in the early 1950s for producing ACTH (adrenocorticotropic hormone). This is a hormone originally extracted from the pituitary... 

Heparin was originally extracted from liver (hence its name), but commercial preparations are now obtained by extraction from beef lung or porcine gastric mucosa. 

In the purification of pectinesterase from the fruits of Citrus nat-sudaidai,61 fractional salting-out with ammonium sulfate was followed by chromatography on a column of DEAE-cellulose and by separation of the active fraction on Sephadex G-100. A preparation (purified solution) having a specific activity 460-fold greater than that of the original extract was obtained. Its homogeneity was checked by disc electrophoresis, and its amino acid content was determined and fundamental, kinetic data were obtained. 

Prepare samples (maximum of two) by grinding and weighing 5 g of each into 500-mL Erlenmeyer flasks. Add 50 mL of the HC1 solution prepared in step 1 to each. Bring each to a boil on a hot plate, and then simmer for 5 min. Cool and transfer the supernatents for each to separate 100-mL volumetric flasks. Dilute to the mark with distilled water and shake. Filter each through Whatman 1 filter paper into dry 250-mL Erlenmeyer flasks. Pipet 1 mL of each of these extracts into other clean 100-mL volumetric flasks, and dilute to the mark with water. Save the original extracts in case more dilutions are needed. 

In the main, the original extractive alkylation procedures of the late 1960s, which used stoichiometric amounts of the quaternary ammonium salt, have now been superseded by solid-liquid phase-transfer catalytic processes [e.g. 9-13]. Combined soliddiquid phase-transfer catalysis and microwave irradiation [e.g. 14-17], or ultrasound [13], reduces reaction times while retaining the high yields. Polymer-supported catalysts have also been used [e.g. 18] and it has been noted that not only are such reactions slower but the order in which the reagents are added is important in order to promote diffusion into the polymer. 

As with the studies on the herbicide spray equipment testing grids at Eglln AFB, Florida, the studies of the biodegradation plots confirmed the presence and persistence of TCDD. Analysis of soil samples collected from the Utah plots in 1978 indicated that 85 percent of the amount of TCDD originally extracted In 1972 could be recovered, suggesting that TCDD applied subsurface was minimally disappearing. 

As indicated previously, it is important to look at the individual trace elements in the coal extract solution. Table 9 shows the concentration of trace elements in the ash from the original extract and the filtrate produced after toluene extraction. This was for an extract with an ash level of 350 ppm, extracted with toluene at 165 C to give a filtrate with an ash level of 100 ppm. The results show that there are some differences, with Ca reducing and Fe and Ti increasing their proportions. However, the changes are not great and it would be expected that if the filtrate were fed to the hydrocracker it would deposit trace elements as observed previously Q), except, of course, there would be a smaller quantity overall. 

However, examination of the filtrate showed that it was much more fluid than the original extract and it appeared that some toluene remained in it. To investigate this, analysis of the extract and ffltrate were carried out by an initial vacuum distillation followed by GC analysis of the distillate. The results are shown in Table 10. 

Peruvian Incas used elemental mercury to wash gold-bearing gravel as early as 1557. The original extraction process, which took place over 20 to 30 days, underwent subsequent modification, leading to the ability to extract gold in a pan over a fire in less than 6 hours by the 1830s. With some modifications this process continues to be used to this day, especially in Central and South America, Africa, and the Philippines. 

Penicillin was originally extracted from the mould Penicillium notatum but now it is extracted from its related mould Penicillium chrysogenum due to its high yield. Penicillin consists of thiazolidine ring fused with a beta lactam ring which is essential for its antibacterial activity. These two rings forms a nucleus named as 6-aminopenicillanic acid. 

As reported in the previous section, AEDA is performed with a concentrated aroma extract. However, concentration of the volatile fraction might lead to losses of odorants, e.g. by evaporation and by enhanced side reactions in the concentrated extract. Consequently, the odour potency of these odorants can be underestimated in comparison to those whose levels are not reduced during concentration. To clarify this point, aroma extract concentration analysis (AECA) [56] should check the results of AEDA. AECA starts with GC-O of the original extract from which the non-volatile components have been removed. The extract is then concentrated stepwise by distilling olf the solvent, and after each step an aliquot is analysed by GC-O [56]. 

Transfer the 5 mL of extract quantitatively to a 15 mL conical screw-capped centrifuge tube. Rinse the flask with two portions of 2 mL of ether and combine with the original extract. 

Only in 1990 were the remains of the original extract stored by Daly subjected to modern analytical methods and the structure of the compound - which was named epibatidine - finally elucidated by spectroscopic methods, especially IR and NMR techniques (Spande et al., 1992 Daly, 1993 Daly et al., 2000). This was published in 1992 -12 years after the initial publication on Epipedobates tricolor extracts (Daly et al., 1980) and very shortly after Daly and co-workers had filed patents on epibatidine and close structural analogs (see Epibatidine). 

Transfer the filter paper to a Soxhlet extractor using the original extracting flask containing the mineral jelly. Extract the paper for 2 hours with ethyl ether. Distil the ether from the flask on a water bath and then in an oven at 100°C to constant weight. Calculate the % MJ from the formula ... 

Transfer the upper organic (i.e., hexane) layer into a clean, labeled glass tube with a -1 mm-deep layer of anhydrous sodium sulfate on the bottom. Extract the lower aqueous layer from the original extraction again as described in step 5 to remove residual FAME. 

More recently, Manabe (3A) purified PE from Citrus natsudaidai fruit by chromatography on a DEAE-cellulose column followed by Sephadex G-100 column adsorption of the active fraction. The final preparation was homogeneous as determined by disc electrophoresis and was A60 times as active as the original extract on a protein basis. 

Originally, extractive distillation was limited to two-component problems. However, recent developments in solvent technology enabled applications of this hybrid separation in multicomponent systems as well. An example of such application is the BTX process of the GTC Technology Corp., shown in Figure 6, in which extractive distillation replaced the conventional liquid-liquid extraction to separate aromatics from catalytic reformate or pyrolysis gasoline. This led to a ca. 25% lower capital cost and a ca. 15% decrease in energy consumption (170). Some other examples of existing and potential applications of the extractive distillations are listed in Table 6. 

Acree et al. (28, 29) used a video-terminal in addition to the gas chromatograph. They calculated CHARM-values on the basis of the duration of the sensory responses which were maintained during the GC-effluent sniffing of three-fold dilutions of the original extract. CHARM-values are directly proportional to odor units. 

The cleaned-up residue is dissolved in 25 ml of 6N HC1 by sonication and the resulting solution transferred to a separatory funnel. The flask is then rinsed with 50 ml of dichloromethane which is likewise transferred to the separatory funnel. The TPTCl is partitioned into the dichloromethane, which is removed, filtered and dried through a pad of sodium sulfate. The aqueous phase is extracted again with an additional 50 ml of dichloromethane. The organic phase is dried over the sodium sulfate, combined with the original extract, and evaporated to dryness on a rotary flash evaporator. 

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