Group specificity

Herbicidal Inhibition of Enzymes. The Hst of known en2yme inhibitors contains five principal categories group-specific reagents substrate or ground-state analogues, ie, rapidly reversible inhibitors affinity and photo-affinity labels suicide substrate, or inhibitors and transition-state, or reaction-intermediate, analogues, ie, slowly reversible inhibitors (106). 

An example of the use of polyacrylamide gels in an ief system in combination with immun obi otting is given in Reference 40 where this method is used to detect low quantities of group specific component (GC) subtypes. Another example of polyacrylamide in combination with ief is given in Reference 41 where the technique is used as a screening tool for inheritance of a certain polymorphic protein. 

In recent years the application of photocycloaddition reactions to organic synthesis has been growing in importance. - The procedure described is illustrative of a general method based on a photocycloaddition reaction for the introduction of an activated alkyl group specifically to the a-carhon atom of an a,/3-unsaturated cyclohexenone. Especially significant is the fact that the method is also applicable to... 

In spite of numerous advances in the field of detection there are not and never have been any genuinely substance-specific chemical detection reactions. This means that, unlike the spectrometric methods, the methods of detection normally employed in chromatography cannot be employed for an unequivocal identification of compounds, they can only provide more or less definite indications for the characterization of the separated substances. Universal reagents are usually employed for a first analysis of the separation of samples of unknowns. This is then followed by the use of group-specific reagents. The more individual the pieces of information that can be provided from various sources for a presumed substance the more certainly is its presence indicated. However, all this evidence remains indicative it is not a confirmation of identity. 

Although the yields of 38 were high, the oxindole (39) was also formed as a by-product. This exemplifies the problem of reducing the nitro group specifically to a hydro xylamine. 

Then follows a selection of group-specific reagents, in response to requests from practical workers after the publication of Volume 1 a. This part should be seen in reference to the monographs that follow or have already been published. 

These few questions serve to demonstrate that there must be great interest in characteri2dng chemical compounds by means of their reactive functional groups. The most important group-specific reagents for postchromatographic derivatization are listed alphabetically in Table 4 below ... 

If a group-specific reagent is now used, e.g. one that is chosen to react specifically with the reducing properties of aldehydes (ammoniacal silver nitrate solution) or to react with ketones (2,4-dinitrophenylhydrazine [9]) it is very simple to determine which form of alcohol is present in the sample. 

Group-specific reagents can provide evidence to characterize the substance,... 

It is very often advantageous in thin-layer chromatography to be able to obtain a preliminary impression of a substance separation by first exposing the plate to a rapidly carried out, economically priced universal reaction before passing on to final characterization using group-specific or even better substance-specific reactions. 

Impregnation with ammonium acetate or ammonium hydrogen sulfate serves the same purpose [11-13]. In conjunction with the TLC separation previously carried out it is even possible to obtain group-specific and sometimes substance-speciflc information. 

Desoxyadenosine oligonucleotides la 76 Desoxycholic acid la 334 11-Desoxycorticosterone la 221 lb 346 Detection, group-specific la 4,7 -, substance specific la 4,7 Detection of lipqjhilic substances la 43 -, biological-physiologically la4,6,7, 9,109... 

For functionalization of S-layer-coated liposomes, the S-layer lattice was stabilized by cross-linking the S-layer subunits with either periodate-oxidized raffinose or bis(sulfo-succinimidyl) suberate (BS ). Both are amine group-specific reagents that were large and... 

There are solitary examples of other alditol phosphates as components of this class of polymers. Arabinitol 1-phosphate is part of the S. pneumoniae type 17F capsular polysaccharide. o-Glucitol 6-phosphate is a component of the group-specific polysaccharide from group B Streptococcus, which has a most unusual, ramified structure. In a polysaccharide from Nocardia... 

Group Specific mechanism Examples Additional notable actions... 

There are many ligands and group-specific reagents that have been demonstrated to alter the properties of H,K-ATPase, and which are not clinically useful. For example, there is a variety of chemicals that have been used in studies on structure-function relations of H,K-ATPase and that inhibit the enzyme in vitro by modification of its amino [49,67,158], sulfhydryl [95,165,166] or carboxyl groups [140]. 

Influence of substrates and inhibitors on reactivity towards group-specific reagents The first evidence suggesting the involvement of a conformational change in the... 

Effects of group-specific reagents on transport activity and regulation of plasma membrane Na /H exchangers... 

Further evidence that carboxyl groups are important for transport activity was provided by Igarashi and Aronson [22], Friedrich et al. [23], and Kinsella et al. [24] using the carboxyl group-specific reagent, A,A -dicyclohexylcarbodiimide (DCCD). DCCD irreversibly inactivated the brush border Na /H exchanger in rabbit and... 

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