Hormones, separation

As an alternative method of procedure, the following may be substituted for Steps 4 to 7 inclusive of the above process. After distilling the benzol, the tarry mass may be stirred directly with 2000 mL of hot 0.3 N NaOH with a mechanical stirrer. The suspension is chilled and the supernatant Liquid poured or siphoned off. Repetition of the extraction two or three times is advisable. The alkaline aqueous solution is then extracted five or six times with 400 mL portions of sulfuric ether, thus transferring the hormone to ether solution. After distillation of the ether the residue is steam distilled as long as a distillate other than water is obtained. The condensed water is removed by vacuum distillation and the small amount of dark tarry residue leached 5 times with 50 mL of hot 0.3 N NaOH. This solution is filtered and the filtrate extracted with sulfuric ether (100 mL, 6 times). The ether solution is distilled and the residue leached with cold 0.3 N NaOH using 20 mL five times. This alkaline solution is filtered and extracted with 50 mL of sulfuric ether five times. Upon distillation of the ether and solution of the residue in a small quantity of hot ethyl alcohol, the hormone separates in semi-crystalline balls which may be filtered off. A further quantity is obtained by adding 3 volumes of water to the alcoholic solution. It may be recrystallized from 25% aqueous ethyl alcohol or from 25% aqueous acetone or from any of the following chloroform, benzol, ethyl acetate, ethyl ether or petroleum ether. The final product consists of colorless crystals which, when crystallized from dilute alcohol, possess a distinct rhomboid outline. The crystals melt at 242-243°C (248-249°C corrected) with some decomposition. 

Figure 13. (A) Analysis of four juvenile hormones separated on a...

Oxytocin and Vasopressin Receptors. The actions of oxytocin and vasopressin are mediated through their interactions with receptors. Different receptor types as well as different second messenger responses help explain their diverse activities in spite of the hormones stmctural similarities. Thus oxytocin has at least one separate receptor and vasopressin has been shown to have two principal receptor types, and V2. Subclasses of these receptors have been demonstrated, and species differences further compHcate experimental analysis. It is apparent that both oxytocin and receptors function through the GP/1 phosphoHpase C complex (75), while the V2 receptors activate cycHc AMP (76). 

Several parenteral microencapsulated products have been commercialized the cote materials ate polypeptides with hormonal activity. Poly(lactide— glycohde) copolymers ate the sheU materials used. The capsules ate produced by solvent evaporation, polymer-polymer phase separation, or spray-dry encapsulation processes. They release their cote material over a 30 day period in vivo, although not at a constant rate. 

Chemical Assay. In view of the similarity of their chemical and physical properties (see Table 1) (29), the main problem in the chemical analysis of the thyroid hormones is their separation. A USP procedure gives the details of a paper chromatographic separation in which T is examined for contamination by T and 3,5-diiodothyroiiine (30). Other systems are also employed (29). 

Retinyl acetate [127-47-9] M 328.5, m 57". Separated from retinol by column chromatography, then crystd from MeOH. See Kofler and Rubin [Vitamins and Hormones (NY) 18 315 1960] for review of purification methods. Stored in the dark, under N2 or Ar, at 0°. See Vitamin A acetate p. 574 in Chapter 6. 

Follicle Stimulating Hormone (FSH, foilitropin) [9002-68-0] Mr 36,000. Purified by Sephadex GlOO gel filtration followed by carboxymethyl-cellulose with NH4OAC pH 5.5. The latter separates luteinising hormone from FSH. Solubility in H2O is 0.5%. It has an isoelectric point of 4.5. A soln of Img in saline (lOOmL) can be kept at 60° for 0.5h. Activity is retained in a soln at pH 7-8 for 0.5h at 75°. The activity of a 50% aq EtOH soln is destroyed at 60° in 15 min. [Bloomfield et al. Biochim Biophys Acta 533 371 1978 Hartree Biochem J100 754 1966 Pierce and Parsons Ann Rev Biochem 50 465 1981.]... 

Manual transfer of the chromatographically separated substance to the detector . These include, for example, the detection of antibiotically active substances, plant and animal hormones, mycotoxins, insecticides, spice and bitter principles and alkaloids. The frequency distribution of their employment is shown in Figure 54 [295]. 

A disulfide bond between cysteine residues in different peptide chains links the otherwise separate chains together, while a disulfide bond between cysteine residues in the same chain forms a loop. Such is the case, for instance, with vasopressin, an antidiuretic hormone found in the pituitary gland. Note that the C-terminal end of vasopressin occurs as the primary amide, -CONHz, rather than as the free acid. 

Fermentation broths are complex, aqueous mixtures of cells, comprising soluble extracellular, intracellular products and any unconverted substrate or unconvertible components. Recovery and extraction of product is important in bioprocess engineering. In particular separation is a useful technique it depends on product, its solubility, size of the process, and product value. Purification of high-value pharmaceutical products using chromatography such as hormones, antibody and enzymes is expensive and difficult to scale up.1 Tire necessary steps to follow a specific process depend on the nature of the product and the characteristics of the fermentation broth. There are a few steps for product recovery the following processes are discussed, which are considered as an alternative for product recovery from fermentation broth. 

A final example of the use of silica gel as an interactive stationary phase is afforded by the separation of some steroid hormones shown in figure 12. 

The column used was 25 cm long, 4.6 mm in diameter, and packed with silica gel particle (diameter 5 pm) giving an maximum efficiency at the optimum velocity of 25,000 theoretical plates. The mobile phase consisted of 76% v/v n-hexane and 24% v/v 2-propyl alcohol at a flow-rate of 1.0 ml/min. The steroid hormones are mostly weakly polar and thus, on silica gel, will be separated primarily on a basis of polarity. The silica, however, was heavily deactivated by a relatively high concentration of the moderator 2-propyl alcohol and thus the interacting surface would be covered with isopropanol molecules. Whether the interaction is by sorption or displacement is difficult to predict. It is likely that the early peaks interacted by sorption and the late peaks by possibly by displacement. 

This compartment contains about one-third of total body water and is distributed between the plasma and interstitial compartments. The extracellular fluid is a delivery system. It brings to the cells nutrients (eg, glucose, fatty acids, amino acids), oxygen, various ions and trace minerals, and a variety of regulatory molecules (hormones) that coordinate the functions of widely separated cells. Extracellular fluid removes COj, waste... 

Separate lines of research have implicated either the noradrenergic, serotonergic or the FIFA axis in depression, and there is more evidence, not covered here, that other neuroendocrine systems are involved as well. Yet, all this effort has so far failed to identify disruption of any single transmitter or hormone system as the sole culprit. This points to disruption of the interactions between these different systems as the cause of the problem. 

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