Active compounds examples

Nencki introduced salol in 1886 and. so pre.sented to the science of therapy the "salol principle." In salol. two toxic sub.stances (phenol and salicylic acid) were combined into an e.ster that taken internally slowly hydroly/es in the intestine to give the antiseptic action of its components. This type of ester is referred to as a full. salol or true salol when toth components of the ester are active compounds. Examples are guaiacol benzoate. /3-naphthol benzoate, and salol. The salol principle can be applied to esters in which only the alcohol or the acid is the toxic, active or corrosive portion this type is called a partial salol. Examples of partial sulols that contain an active acid arc ethyl salicylate and methyl salicylate. Examples of partial sulols that contain an active phenol are creosote carbonate, thymol carbonate, and guaiacol carbonate. Althtxigh many. salol-typc compounds have been prepared and used tu. some extent, none is presently... 

Homogeneous asymmetric hydrogenation of amino- or hydroxy ketones is apphed to the synthesis of some biologically active compounds. Examples are given in Fig. 8 [4b, 19g, 47,48c, 50]. (R)-l,2-Propanediol obtained by hydrogenation of 1-hydroxy-2-propanone in the presence of an (R)-BINAP-Ru complex is now commercially used for the synthesis of levofloxacin, an antibacterial agent (Dai-ichi Pharmaceutical Co.) [19g]. 

The structure-selective, electron-capture detector (ECD) is the second most widely used ionization detector [254,293-295]. It owes its popularity to its unsurpassed sensitivity to a wide range of environmentally important and biologically active compounds. Examples of general applications include the determination of pesticides and industrial chemicals in the environment, assessment of the fate of ozone-depleting chemicals in the upper atmosphere and the determination of drugs and hormones in biological fluids. 

Okamato et al. [11] also examined the relative performance of cellulose and amylose derivatives for the separation of a group of racemic drugs. At the same time, they demonstrated generally the versatility of the cellulose based chiral stationary phases for the separation of a range of physiologically active compounds. Examples of such separations are shown in figure 11.13 (A-F). 

The ECD owes its popularity to its unsurpassed sensitivity to a wide range of environmentally important and biologically active compounds. Examples of... 

Several examples of Martinet reactions have been reported for the preparation of biologically active compounds. Examples include studies targeting Mescaline analogs such as 45. More recent examples include aminopeptidase II inhibitors (48), monoamine oxidase (MAO) inhibitors... 

It is interesting that the retrosynthetic approach to heterocycles is not considered in monographs or review articles on the synthesis of individual classes of heterocyclic compounds. The examples that follow illustrate the retrosynthetic approach to the five- and six-membered heterocyclic structures often encountered in natural or synthetic biologically active compounds. Examples 7.2, 7.3, 7.6, 7.11 and 7.12 demonstrate syntheses of biologically active compounds developed to large-scale production by chemists at PLIVA Co. (Croatia). 

In addition to N9-substituted acridines, several C9-substituted acridines have been described as biologically active compounds. Examples are shown... 

Astemi2ole (10) has further been modified into a series of 4-phenylcyclohexylamine compounds, resulting in the synthesis of cabastine, for example. Cabastine is a highly active compound and its geometric isomers are also active, demonstrating the stereoselectivity of histamine receptors toward chiral ligands. The > S, 4 R-levo antipode of cabastine was the most active, and therefore this isomer, levocabastine (13), has been chosen for further development. Because of high potency, levocabastine has been developed for topical appHcation such as eye drops and nasal spray. 

Catalysts commonly lose activity in operation as a result of accumulation of materials from the reactant stream. Catalyst poisoning is a chemical phenomenon, A catalyst poison is a component such as a feed impurity that as a result of chemisorption, even in smaH amounts, causes the catalyst to lose a substantial fraction of its activity. For example, sulfur compounds in trace amounts poison metal catalysts. Arsenic and phosphoms compounds are also poisons for a number of catalysts. Sometimes the catalyst surface has such a strong affinity for a poison that it scavenges it with a high efficiency. The... 

Another characteristic of enzymes is their frequent need for cofactors. A cofactor is a nonproteia compound that combines with the otherwise iaactive enzyme to give the active enzyme. Examples of cofactors are metal ions such as Ca ", Cu ", Co ", Fe ", and and organic molecules such as... 

Examine the structure of penicillin model (R=H), a model for the active compounds. What, if anything, distinguishes it from a typical amide (N,N-dimethylacetamide, for example) What is responsible for the differences Compare electrostatic potential maps for penicilhn model and dimethylacetamide. Which compound is more likely to undergo nucleophilic attack Explain. 

The oxetane functional unit is a rare but occurring group in natural products and appears both as end products as well as synthetic intermediates. Patemo-Buchi reactions can be used to insert oxetanes directly into biologically active compounds, as in the example... 

Although estrone and estradiol (26) have both been isolated from human urine, it has recently been shown that it is the latter that is the active compound that binds to the so-called estrogen receptor protein. Reduction of estrone with any of a large number of reducing agents (for example, any of the complex metal hydrides) leads cleanly to estradiol. This high degree of stereoselectivity to afford the product of attack at the alpha side of the molecule is characteristic of many reactions of steroids. 

Diugs with metabolic interactions that can enhance the half-life of active compounds. An example of this regimen is the interaction between azole- and vitamin D-deiivatives that inhibit the metabolism of retinoids in skin cells leading to increased intracellular amounts of active RA-isomers. Further study and the identification of novel interactions of this type ofdtug interaction is of great clinical interest since they may decrease the dose of retinoids required for efficacy thereby also reducing the risk of side effects of the retinoids. 

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