Samarium Diiodide Promoted Reactions on Thiophene Moieties & Synthesis and Applications of Carbohyrdrate Encapsulated Nanoparticles

• Main Authors: Anandakathir Robinson, 魯濱孫
• Other Authors: Jim-Min Fang
• Format: Others
• Language: en_US
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/19990275889162138446

博士 === 國立臺灣大學 === 化學研究所 === 91 === Abstract Part 1. Samarium Diiodide Promoted Reactions on Thiophene Moieties Remote functionalization is a challenging task for organic chemists. Methyl 2’,5-bithiophene-2-carboxylate serves as an attractive mediator for distant functionalizations, since it can generate a carbanion at the C-5 position on treatment with SmI2/HMPA. We describe herein a new strategy for generation of the synthetic equivalents of nonanoate 9-anion and nonanoate 8,9-dianion, which are not readily accessible from the known methods. It is believed that a planar hydrophobic moiety is capable for the DNA intercalation with appropriate linker. The carbohydrate moieties in antibiotics (anthracycline and calicheamicin,etc.) can serve as recognition sites toward DNA and provide an improved solubility in water system. We have synthesized the piceno[13,14-b] thiophene-2-carbozylic acid and its sugar derivatives which show intercalation with calf thymus DNA. The compounds were synthesized using methyl 2-thiophenecarboxylate, α-tetralone and D-(+)-glucose as the starting materials. Part 2. Synthesis and Applications of Carbohyrdrate Encapsulated Nanoparticles Carbohydrate-protein interaction has been viewed as an important phenomenon in biological processes, especially in cellular recognition processes and information transfer processes between cells. Generally, carbohydrates show enormous structural and functional diversity, and interact with proteins non-covalently. This kind of interaction is monovalent and weak, so that multivalent interactions that exhibit the so called “Cluster effect” help to overcome this problem. Synthesis of multivalent species will play an important role in drug discovery. We herein report the encapsulation of carbohydrates on gold nanoparticles and fluorescent quantum dots (CdSe)ZnS which have advantageous properties such as size-tunable emission, narrow spectral line widths, high luminescence, continuous absorption profiles and stability against photo bleaching. These nanoparticles were used for labeling experiments on sperms and for binding study with lectin.