Enzymatic release

Exceptions to the simple definition of an essential oil are, for example, gadic oil, onion oil, mustard oil, or sweet birch oils, each of which requires enzymatic release of the volatile components before steam distillation. In addition, the physical process of expression, appHed mostly to citms fmits such as orange, lemon, and lime, yields oils that contain from 2—15% nonvolatile material. Some flowers or resinoids obtained by solvent extraction often contain only a small portion of volatile oil, but nevertheless are called essential oils. Several oils are dry-distiUed and also contain a limited amount of volatiles nonetheless they also are labeled essential oils, eg, labdanum oil and balsam oil Pern. The yield of essential oils from plants varies widely. Eor example, nutmegs yield 10—12 wt % of oil, whereas onions yield less than 0.1% after enzymatic development. 

Consumer acceptance of milk is strongly determined by its sensory characteristics. The development of off-flavor in milk as a result of lipolysis can reduce the quality of milk. The enzymatic release, by milk lipase, of free fatty acids (FFA) from triglycerides causes a flavor defect in milk described as rancid . Triglycerides in milk contain both long chain and short chain fatty acids, which are released at random by milk lipase. The short chains FFA, like butyric acid, are responsible for the off-flavor. 

To allow all culture productiou to be coutrolled, a method for rapid analysis is required. Prior to development of an LC-MS method, the analysis was both complex and time-consuming, involving the purification of a relatively large amount of the antibody using affinity chromatography, enzymatic release, and subsequent derivatizafion of the oligosaccharides and their analysis by using capillary electrophoresis. 

Molecular weight of the components of the enzymatic complex was determined using a Sephadex G —75 column after its calibration by dextrans with molecular weight equal to 10,000, 40,000 and 70,000 and rafinose with molecular weight of 504. Fractions were also analyzed by the disk —electrophoresis method in PAAG (7) using 7.5% polyacrilamide gel (pH 4.3). Activity of pectinesterase was determined by titrometric method [8]. The enzymatically released methanol analyzed by gas—liquid chromatography [9]. 

Pfeifer F, HG Trtiper, J Klein, S Schacht (1993) Degradation of diphenylether by Pseudomonas cepacia Et4 enzymatic release of phenol from 2,3-dihydroxydiphenylether. Arch Microbiol 159 323-329. 

For the Diels-Alder reaction, polymer-bound acrylic acid ester (73) was treated with cyclopentadiene. The cycloaddition product (74) was formed with an endo/exo ratio of 2.5 1 and with quantitative conversion. The subsequent enzymatic release delivered the corresponding alcohols (72, 75) in high yield and purity. 

The secretion of T4 and T3 requires the uptake of follicular contents across the follicular cell apical membrane, the enzymatic release of T4 and T3 from peptide linkage within Tg, and the transport of T4 and T3 across the follicular cell basal membrane to the blood. Several of the steps in synthesis and secretion of T4 and T3 may be compromised by iodine deficiency or disease and can be blocked selectively by a variety of chemicals and drugs. 

Unlike the hormones described above, they are not synthesized in advance and stored they are produced, when needed, from arachidonate enzymatically released from membrane phospholipids by phospholipase A2 (see Fig. 10-18). The enzymes of the pathway leading to prostaglandins and thromboxanes (see Fig. 21-15) are very widely distributed in mammalian tissues most cells... 

Chlorobenzoyl-CoA dehalogenase. The enzymatic release of chloride ion from 4-chloroxybenzoyl-CoA... 

Exceptions to the simple definition of an essential oil are, for example, garlic oil, onion oil, mustard oil, or sweet birch oils, each of which requires enzymatic release of the volatile components before steam distillation. In addition, rhe physical process of expression, applied mostly to citrus fruits such as orange, lemon, and lime, yields oils that contain from 2-15% nonvolatile material. 

Proteinase Inhibitor Inducing Factor Activity in Tomato Leaves Residues in Oligosaccharides Enzymatically Released From Cell Walls. Proceedings National Academy of Science DSA 78, 3536-... 

The formation of metal-bound diazene from dinitrogen and its subsequent disproportionation is a plausible mechanism of action of nitro-genase (54). The disproportionation of free diazene is well established (Section V,A) although such reactions of metal-bound diazene are as yet unknown. The enzymatic release of a reactive species such as cis-, trans-, or iso-diazene would be unexpected but cannot be ruled out. 

The inducibility of Prl by proteinaceous compounds released enzymatically from insect cuticle was also studied inM anisopliae (Paterson et al., 1994b). In the case of Schistocerca gregaria cuticle treated with KOH in order to remove proteins, no induction of Prl production was observed, while cuticle treated with chloroform or ether to remove lipids was able to induce enzyme production. Digestion of cuticle with Prl or the trypsin-like protease Pr2 ofM anisopliae resulted in peptides mainly in the range of 150-2000 Da. The addition of these peptides at 3 pg Ala equivalents ml"1 led to the induction of Prl production to a level (75%) similar to that observed in the case of untreated insect cuticle. The ability of various amino acids and peptides abundant in insect cuticular protein (Ala, Gly, Ala-Ala, Ala-Ala-Ala, Ala-Pro and Pro-Ala) to induce Prl was tested but none of them was found to increase enzyme production in the levels observed with cuticle, or peptides enzymatically released from the cuticle. 

Changes in bioengineered expression systems can alter the number and composition of carbohydrate residues attached to recombinant or monoclonal antibody products [301]. The use of high pH anion-exchange HPLC and pulsed amperometric detection (Dionex Corp) has enabled the analytical profiling or mapping of the characteristic biantennary carbohydrate structures following their enzymatic release from both murine and humanized monoclonal antibodies [302]. 

Profile Analysis of Oligosaccharides from Glycoproteins by PMP Labeling. Comparison of Chemical and Enzymatic Release Methods Using RP-HPLC and Mass Spectrometry... 

Figure 2. Mass spectrometric analysis of the PMP-labeled N-linked oligosaccharide (HPLC peak 3). MALDI TOF mass spectnim of (A) chemically, (B) enzymatically released oligosaccharide, and (C) deconvoluted LC ESI mass spectrum of enzymatically released oligosaccharide. Asterisks denote fragments due to the loss of one PMP molecule.

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