6-Amino-1-hexanol

Levuglandin (LG) E2 is rapidly sequestered by covalent binding with proteins. The reaction of LGE2 with a protein in neutral aqueous solution exhibits two phases. A metastable adduct rapidly accumulates initially. In the second phase, a protein-bound pyrrole is generated. Pyrrole formation and stability were monitored with an immunoassay using antibodies that were raised against a stable isostere. That LG-derived pyrroles are the major products (> 76%) of the LGE2-protein reaction is suggested by the level of antibody binding found for LG-protein adducts compared with that found for a pyrrole derived from LGE2 and 6-amino-1-hexanol. Because the initial metastable LG-protein adduct is a reactive electrophile, it can be trapped with amines, such as glycine, to give stable ternary adducts that do not cross-react with the antibodies. Although highly alkylated pyrroles are chemically sensitive compounds, the protein-bound LG-derived pyrrole appears to be stable in aqueous solution at pH 7.4. Thus, it shows no decrease in immunoreactivity over several weeks. This discovery leads to the expectation that such pyrroles will accumulate in vivo, especially in proteins that do not turn over rapidly. Thus, the LG-derived protein-bound pyrrole may be a useful marker of oxidative lipid damage, and an immunoassay for this post-translational protein modification can be exploited as a mild, sensitive method for detecting and quantifying the generation of LGs in chronic inflammatory states.

All simple structures with saturated hydrogen bonding (SHB) are classified into eight categories on the basis of the donor and acceptor numbers on the atoms at each end of the hydrogen bonds. Examples from the literature are included where known, along with seven structures investigated as part of this study (five have SHB). Graph-set descriptions of the hydrogen-bond patterns are given for each of these structures and for some selected literature examples. The structures presented are: piperazine (I), morpholinium chloride (II) and iodide (III) [(II) and (III) are not SHB], three 1:1 cocrystals of diols with 1,4-phenylenediamine (PDA)--PDA.1,8-octane diol (IV), PDA.1,10-decane diol (V), and PDA.1,12-dodecane diol (VI) and 6-amino-1-hexanol (VII). This study discusses some structures that show limitations of the graph-set model, along with possible suggestions to cover these limitations. The cocrystalline PDA.aliphatic diol structures may provide details applicable to the structure of self-assembled monolayers of aliphatic thiol molecules on Au(111) surfaces.

Acetylcholinesterase (AChE) from Pseudomonas aeruginosa PAO1 has a catalytic Ser residue in its active site. In this study, we examined the aminolysis and alcoholysis reactions of AChE that occurred alongside its hydrolysis reaction. The recombinant AChE recognized ethyl acetate as a substrate. Therefore, we evaluated acetylation of the amine and hydroxyl group by AChE, using acetylcholine and ethyl acetate as the acetyl donor. AChE recognized diaminoalkanes with 4- to 12-carbon chains and aminoalcohols with 4- to 8-carbon chains as acetyl acceptors, resulting in their acetylated products. In the acetylation of 1,6-diaminohexane, AChE preferentially used ethyl acetate as the acetyl donor above pH 8.0 and the efficiency increased with increasing pH. In contrast, the acetylation of 6-amino-1-hexanol was efficient with acetylcholine as the acetyl donor in the pH range of 4-10. In addition, acetylated 6-amino-1-hexanol was decomposed by AChE. The kinetic study indicated that the acetyl donor and acceptor are competitively recognized by AChE as substrates.