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Both the negatively charged anion HO −, called hydroxide, and the neutral radical HO·, known as the hydroxyl radical, consist of an unbonded hydroxy group. According to IUPAC definitions, the term hydroxyl refers to the hydroxyl radical (·OH) only, while the functional group −OH is called a hydroxy group. [1]
The hydroxyl group plays a role in forming a water-induced bond with glutamine (Gln240) on the target enzyme. Drugs that have no hydroxyl group initially cause better inhibition than parent compounds, without hydroxyl group the drug seems to fit more easily into the open active site. The absence of hydroxyl group however reduces the ability to ...
The acidity of the hydroxyl group in phenols is commonly intermediate between that of aliphatic alcohols and carboxylic acids (their pK a is usually between 10 and 12). Deprotonation of a phenol forms a corresponding negative phenolate ion or phenoxide ion , and the corresponding salts are called phenolates or phenoxides ( aryloxides according ...
As hygroscopic moisturizers, humectants work by attracting water to the upper layer of the skin (stratum corneum). [14] All humectants have common hydroxyl groups which allow them to participate in hydrogen bonding and attract water. This process attracts moisture from the outer layer of the skin or, in high humidity, from the atmosphere.
Imidazole is a planar 5-membered ring, that exists in two equivalent tautomeric forms because hydrogen can be bound to one or another nitrogen atom. Imidazole is a highly polar compound, as evidenced by its electric dipole moment of 3.67 D, [12] and is highly soluble in water.
In chemistry, hydroxylation refers to the installation of a hydroxyl group (−OH) into an organic compound. Hydroxylations generate alcohols and phenols, which are very common functional groups. Hydroxylation confers some degree of water-solubility. Hydroxylation of a hydrocarbon is an oxidation, thus a step in degradation.
In air, terpenoids are converted into various species, such as aldehydes, hydroperoxides, organic nitrates, and epoxides [11] by short-lived free radicals (like the hydroxyl radical) and to a lesser extent by ozone. [12] These new species can dissolve into water droplets and contribute to aerosol and haze formation. [13]
In some cases, both hydrophilic and hydrophobic properties occur in a single molecule. An example of these amphiphilic molecules is the lipids that comprise the cell membrane . Another example is soap , which has a hydrophilic head and a hydrophobic tail, allowing it to dissolve in both water and oil.