Congene

Synthesis of camptothecin (163) is another example[133]. The iboga alkaloid analog 164 has been synthesized smoothly by the intramolecular coupling of iodoindole and unsaturated ester to form an eight-membered ring. Af-Methyl protection of the indole is important for a smooth reaction[134]. An efficient construction of the multifunctionalized skeleton 165 of congeners of FR900482 has been achieved[135]. 

The mode of action has not yet been elucidated but the manufacturer states that it probably behaves like the herbicide triflurolin and its congeners. These materials inhibit cell division by binding to tubuHn thereby internipting micro-tubule development. This, in turn, stops spindle fiber formation essential to mitosis and cell division. Experiments with C-labeled Prime+ show that it is acutely toxic to fish with estimated LC q (96 h) of less than 100 ppb for rainbow trout and bluegiU. sunfish. However, channel catfish did not exhibit any toxic response at the maximum attainable water concentration (10). 

Petroleum and its lighter congener, natural gas, are the predominant sources of hydrocarbon raw materials, accounting for over 95% of all such materials. Assuring sources of petroleum and natural gas has become a primary goal of national poHcies all over the world, and undoubtedly was one of the principal justifications for the 1992 Gulf War. 

Miscellaneous. The iminostilbene carbama2epiae [294-46-4] congener of the tricycHc antidepressant, imipramine. 

Trigclic Antidepressants. Imipramine (38) was introduced in the late 1950s as one of the first pharmacotherapies for depression. At that time, chlorproma2ine [50-53-3] was the first effective antipsychotic treatment to be discovered. Researchers looked for similar chemical stmctures and imipramine was found to be effective in the symptomatic treatment of depression. Over the years, other congeners, such as desipramine (39), amitriptyline (40), and dothiepin (41), were synthesized and shown to be clinically efficacious antidepressant dmgs (121). These substances, known under the general mbric of tricycHc antidepressants, share a basic chemical stmcture comprising... 

Synthesis. In the syntheses of T and its congeners, formation of the stericaHy hindered diaryl ether core is difficult, as is the introduction of the alanyl side chain (or the preservation of its L (3) absolute configuration) and iodination to the desired degree (T or T. ... 

Congeners. Congeners are the flavor constituents in beverage spirits that are responsible for its flavor and aroma and that result from the fermentation, distillation, and maturation processes. 

Low Wines. Low wines is the term for the initial product obtained by separating (in a pot or Coffey stiU) the beverage spirits and congeners from the wash. Low wines are subjected to at least one more pot stiU distiUation to attain a greater degree of refinement in the malt whiskey. 

Wash. Wash is the hquid obtained by fermenting wort with yeast. It contains the beverage spitits and congeners developed during fermentation. 

The flavor and aroma of distilled spidts are derived primarily from minor constituents called congeners that are produced and augmented in the fermentation and maturation processes. The congener profiles for various distilled spidts are shown in Table 2. 

As in the United States, Canadians use com, rye, and barley malt. Their process is essentially the same as the one used by many distiHedes in the United States. Since they have no limitations on distillation proofs, distillers operate their systems for optimum separation and congener concentration. In addition, they are permitted to add blenders or flavoring components up to 9.06% by volume in the final blending after the aging process. 

Yeast (qv) metabolize maltose and glucose sugars via the Embden-Meyerhof pathway to pymvate, and via acetaldehyde to ethanol. AH distiUers yeast strains can be expected to produce 6% (v/v) ethanol from a mash containing 11% (w/v) starch. Ethanol concentration up to 18% can be tolerated by some yeasts. Secondary products (congeners) arise during fermentation and are retained in the distiUation of whiskey. These include aldehydes, esters, and higher alcohols (fusel oHs). NaturaHy occurring lactic acid bacteria may simultaneously ferment within the mash and contribute to the whiskey flavor profile. 

Age versus congener development ia bourbon stored for eight years has been studied (9). Results iadicate a high correlation of congener formation with age (Table 4). 

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