不对称卟啉化合物的合成及其与氨基酸甲酯的作用

本文合成了含有单取代酰胺基的不对称卟啉及其锌(Ⅱ)络合物Zn(m,2-CNTPP)及Zn(m,3-CNTPP).对三氯甲烷溶液中它们与谷氨酸二甲酯、亮氨酸甲酯以及苯丙氨酸甲酯的作用进行了系统的研究,讨论了卟啉化合物对氨基酸甲酯分子的结合能力、结合方式,以及二者之间的多种存在形式。结果表明,锌卟啉与氨基酸甲酯以1:1的化学计量结合,中心金属锌(Ⅱ)离子和氨基酸甲酯中的氨基配位,卟啉环上的取代基与氨基酸甲酯中的残基可形成氢键、范德华力等弱相互作用。在卟啉和氨基酸甲酯的作用中,氨基与金属离子直接配位,α-碳上的质子靠近卟啉环平面,而酯基中的甲氧基处于远离卟啉环平面的位置。     

ACID-CATALYZED ADDITION OF N-HYDROXYUREA TO 1-ARYL ALCOHOL DERIVATIVES: A NEW SYNTHESIS OF ZILEUTON

A highly efficient synthesis of Zileuton is described in which the key step involves a site-specific alkylation of hydroxyurea under acid catalysis. Various aryl alcohol electrophiles were tested and the reaction was found to be highly substrate-specific, favoring benzothiophene and benzofuran-based alcohols.     

ENZYMATIC SYNTHESIS OF MOLECULAR COMPLEXES OF POLYANILINE WITH DNA AND SYNTHETIC OLIGONUCLEOTIDES: THERMAL AND MORPHOLOGICAL CHARACTERIZATION

The assembly of electronic and photonic materials on biomacromolecules is of tremendous interest for the development of biofunctional nanocomplexes as well as highly selective biosensors. In the context of the use of electrically conducting polymers for sensing, polyaniline (Pani) and polypyrrole have received considerable interest because of their well-known electrical properties. Recently, we have reported an enzyme catalyzed synthetic procedure involving horseradish peroxidase (HRP) for the polymerization of aniline on a calf thymus DNA matrix. The mild reaction conditions involved in the synthesis have provided opportunities for the use of more delicate biomacromolecules as templates. The complexation of Pani with DNA has been found to induce reversible changes in the secondary structure of DNA leading to the formation of an over-wound polymorph. The thermal characterization (melting behavior) of the DNA in the complex and the morphological properties of the complex have provided corroborative evidence for the wrapping of Pani around the DNA matrix. Scanning probe and electron microscopy studies have indicated that the formation of Pani causes the DNA-Pani strands to agglomerate, presumably due to the neutralization of charge on the phosphate groups by the partially charged Pani. We also report the synthesis of Pani on a synthetic oligonucleotide (Poly[dA-dC].poly[dG-dT]). Demonstration of the use of a new biomimetic catalyst, polyethylene glycol modified hematin (PEG-hematin), in these reactions will also be presented. These results indicate that this biocatalytic synthetic approach is generic, versatile and can be adopted for both genomic and synthetic nucleic acids.