Nitrogen mustards chemical structures

Therapeutic Function Cancer chemotherapy Chemical Name 4-[bis(2-chloroethyl)amino]-L-phenylalanine Common Name Alanine nitrogen mustard L-sarcolysine Structural Formula... 

TABLE 8.3. Nomenclature, chemical formulae, and chemical structures of nitrogen mustards... 

Like sulfur mustard, the nitrogen mustards combine predominantly with the thiol group of molecules and are excreted as conjugated cysteinyl derivatives. Both nitrogen and sulfur mustards have structural similarities and have common chemical reactions. A key reaction is the intramolecular cyclization in a polar solvent such as water to form a cyclic onium cation and a free anion. Nitrogen mustards form the immonium cation, while the sulfur mustard forms the sulfonium cation. The cyclized form is responsible for the varied effects of mustards, which are similar. In nitrogen mustard the sulfur is replaced by nitrogen. 

FIGURE 12.1 Chemical structure of sulfur and nitrogen mustards. 

The chemical structure of the nitrogen mustards are shown in Figure 4. 

While nitrogen mustards containing chlorethyl groups constitute the most widely used class of alkylating agents, alternative structures with greater chemical stability and defined activity in specific types of cancer continue to have value in clinical practice. 

The structure of nitrogen mustards differs only in the nature of the third group (R) attached to the amino nitrogen. This group, which can be either aliphatic or aromatic, is the prime determinant of chemical reactivity, oral bioavailability, and the nature and extent of side effects. 

The chemical formula for nitrogen mustard agent HN-3 is N(CH2CH2C1)3, and the structure and molecular formula are shown in Figure 8.36. 

The term blister agents includes a wide range of compounds with diverse physical and chemical properties and chemical structures. They may be broadly grouped under a few general types, namely, the sulfur mustards, nitrogen mustards and organochloro-arsines. There are also some substances that do not fall nnder the above categories. 

Agent HN2 [bis(2-chloroethyl)methylamine mechlorethamine nitrogen mustard CAS no. 51-75-2] is a clear to yellow liquid (see Table 4). Its chemical structure is... 

Landing BH, Goldin A, Noe HA (1949b) Systemic pathological effects of nitrogen mustards, and a comparison of toxicity, chemical structure, and cytotoxic effect, with reference to the chemotherapy of tumors. Cancer (Phila) 2 1055-1066. 

Agents acting by an Sn 2 mechanism can be more selective in the nucleophile sites they attack, since they form transition complexes with some molecules more readily than with others. Other agents in vivo may, because of their chemical structure, concentrate in certain areas, giving effects not predicted from model experiments. This is the case with dimethylmyleran, a sulphonoxyalkane, quite unreactive to nucleophiles in vitro, but quite toxic in vivo. Presumably this is due to its reaction with nucleophiles, which are in the lipid phase where it concentrates. Similarly the biological activity of the aromatic nitrogen mustard chlorambucil is considerably influenced by complexing with serum proteins. 

TABLE 8.3 Nomenclature, Chemical Formulae, and Chemical Structures of Nitrogen Mustards... 

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