Boiled extract

Reflux extraction of additives and wax from polyolefins was reported [116]. Subsequently, the additives were adsorbed onto an adsorbent (Florisil) and the wax was removed from the extract before chromatography. Boiling extractions of SBR are described in ASTM D 1416-89 1 g of rubber is extracted by boiling in two 100 mL portions of 75/25 vol% isopropyl alcohol/toluene. Reflux heating with strong solvents, such as THF, dichloromethane or chloroform has been reported [117]. Reflux extraction has also been used for the 3 h extraction of caprolactam and oligomers from PA6 in boiling methanol. 

The classical Soxhlet extraction technique has seen some improvements, mainly in the submersion of the whole extraction thimble into the boiling extraction solvent, degree of automation, and in reduction of solvent volume. In a recently introduced universal extraction system (Biichi) four SLE methods are contained in one device Soxhlet Standard, Soxhlet warm, hot extraction and continuous flow. It is possible to use solvents with boiling points of up to 150 °C inert gas can be supplied during the extraction process. 

Another cultured cell line of Catharanthus roseus (EU4A), which does not produce detectable amounts of vinblastine and other bisindole alkaloids, was also examined for its ability to transform 78 (183). Cell-free extracts of the culture line were prepared, and the 35,000 X g supernatant solution was used. Incubations with 2r-tritioanhydiovinblastine yielded a mixture from which radioactive vinblastine (52) was isolated. The labeled vinblastine was reisolated after unlabeled carrier was added and rigorously purified by successive thin-layer chromatography, reversed-phase HPLC, and crystallization to constant specific activity. Boiled extracts could not produce labeled 52, thus supporting the involvement of enzymes in the conversion process. 

Decoction. A preparation made by boiling a plant part in water a boiled extract. Dental enamel. A hard, thin, transcluent layer of calcified substance that envelops and protects the dentin of the crown of the tooth. It is the hardest substance in the body and is almost entirely composed of calcium salts. 

The platinocyanides are an interesting set of salts, remarkable, amongst other of their properties, for the tenacity with which they retain the electronegative metal (platinum) and disguise it to ordinary tests. Concentrated nitric or hydrochloric acid, alone or mixed, in the cold or on boiling, extracts no platinum from them. Even concentrated sulphuric acid only liberates platinum cyanide with difficulty.3... 

Figure 9.131 Chromatograms of enzyme activity. (A) Standard of 4 pmol biopterin and 10 pmol pterin (B) brain extract incubated under assay conditions for 60 min (C) boiled extract. The peak eluting at 18 min is imidazole. (From Reinhard et al., 1984.)...

Crud accumulation and thermal decomposition are such grave disadvantages that all high-boiling extractants must be considered inadvisable. 

Harada et al. (148) reported that no significant pharmacological activities were observed for the four synthetic stereoisomers possible for ( )-C-noremetine Pyman [( )-176]. An aqueous (boiled) extract of A. chinense (Lour.) Harms, containing ( )-anabasine (69) as the single active component, was tested for its muscle relaxation effects on laboratory animals and clinical cases (405). A fraction of the CHCI3 extract of A. chinense was found... 

Figure 4 shows simultaneous reaction and product extraction, also called in situ extraction. The reaction of A and B runs in the reactor which contains the polar (e.g., aqueous) catalyst phase. The nonpolar extractant absorbs the organic products which are separated from the polar catalyst phase in the following separation step. The procedure is more costly because a further distillation is necessary in a third unit to separate the products from the low-boiling extractant, which is then recycled to the reactor. 

An important alternative is the successive reaction and product extraction procedure shown in Figure 5. First the reaction of A and B is carried out in a single polar homogeneous phase containing the catalyst. Downstream, the products are extracted with a nonpolar solvent or solvent mixture. In the third unit, the distillation, the low boiling extractant is distilled off and recycled to the extraction unit. Two examples will demonstrate the practicability of this concept. 

In 1951, Dutton and Storey reported that the synthesis of o-amino-phenyl 3-D-glucosiduronic acid requires the presence of boiled liver-extract. They subsequently identified the active principle of the boiled extract as uridine 5-(D-glucopyranosyluronic acid pyrophosphate). This discovery was the first reported instance of transglycosylation from a glycosyl nucleotide. 

In the case of fresh spinach, boiling extracted 48% of the flavonoids, which were recovered in the cooking water. The remaining 52% was found in the cooked spinach. When frozen spinach was boiled, the percentage of flavonoids extracted in the boiling water reached 75% (Tomas-Barberan et al, unpublished results). 

A boiled extraction (Quilliam et al., 1996) will retain the OA group toxins in a natural state and is required for the analysis of sulfated esters (e.g., DTX-4). 

Extractive distillation exploits the differing solubilities of the azeotrope-forming components in a higher boiling extractant. Aids to the selection of suitable extractants (e.g., expert systems) are available [Erdmann 1986a, Trum 1986]. Recovery of the extractant requires an additional downstream column. 

The isolation of FAD, according to Warburg and Christian, involves essentially the following steps. A boiled extract of yeast is filtered and brought to 66% saturation with ammonium sulfate and the coenzyme extracted into phenol. Water and ether are added to the phenol solution, and the coenzyme is driven into the aqueous phase. The dinucleotide is precipitated at pH 2 as the silver salt. 

The non-reactive diluents that have been used rather extensively are the phenolic pitches, which are high boiling extracts of cracked petroleum, and coal tar pitches which are hydrocarbon in nature. These materials are practically solid at room temperature and must be heated prior to use. They are black, and limited to applications where color and transparency are not factors. Their major use has been in road surfacing compounds since they can be used in high concentrations to reduce costs. The coal tars have some plasticizing effect upon the resin, such as improved flexibility, impact resistance, and low moisture absorption. 

Thymine and thymidine are needed to replace folic acid for Streptococcus faecalis, and cells grown on thymine had no detectable folic acid activity for Lactobacillus casei (Stokes, 1944a,b). The inference was that FA was necessary for the s5mthesis of thymine (or thymidine). The site of the folic reaction was soon recognized to be the 5-methyl carbon. Friedkin and Korn-berg (1957) found that P -labeled deoxyuridylic acid was converted to labeled thymidylic acid by extracts of Escherichia coli. As repeatedly the case in many folic-catalyzed cell-free systems, treatment with Dowex-1 stopped the reaction. It was restored by a boiled extract of E. coli, in turn replaceable by FH4. A preliminary note confirms these results (Greenberg and Humphreys, 1958). 

An analysis for the four nonenzymic components listed may be made in the following maimer. The extract of biological material is boiled for 10 minutes or more to destroy enzymic activity. (See Scheme I.) The boiled extract is then divided into several aliquots. One aliquot is tested for ATP by the method outlined in Section II,3,C,4. A tentative estimation of the ADP content can be made from an inspection of the shape of the time curve of luminescence since ADP is converted into ATP by the myo-kinase present in the firefly extract. 

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