【作者】 何翊；

【导师】 孙挺；

【作者基本信息】 东北大学 ， 材料物理与化学， 2006， 博士

【摘要】 乙烯刺激呼吸跃变型果实的后熟和衰老。1-甲基环丙烯（1-MCP）是近年来发现的一种新型的乙烯受体抑制剂，它通过与乙烯受体优先结合的方式，不可逆的作用于乙烯受体，阻止内源乙烯和外源乙烯与乙烯受体的结合，从而抑制其所诱导的与花卉、蔬果等园艺作物后熟或衰老的一系列生理生化反应。由于它无毒、使用时用量低和抑制乙烯作用的效果明显等特点，因此在水果、蔬菜的保鲜储藏方面有着广泛的发展前景。但因为1-MCP的沸点约为10℃，在常温下以气体状态存在，因此使用起来很不方便。为了增加其在贮存期间的稳定性，并保持活性成分，采用一定的技术将1-MCP制成包结物使用，可以克服这些缺陷，从而能大大扩展1-MCP及其衍生物的应用范围。 环糊精（CDs）作为一种多功能分子，具有独特的理化性质和优良的生物学特性。β-CD的孔洞适中，应用范围广，生产成本低，是目前唯一在工业上能大量生产的CDs产品。本课题探索了用β-CD做包结剂来包结1-MCP，在此基础上对包结物进行了一系列的研究，以期为其应用提供可靠的实验数据和理论基础。为了从结构上证明1-MCP对乙烯的抑制效应，并用密度泛函理论对1-MCP分子可能的异构体和稳定性进行了量子化学计算研究。 利用溶液法制备了β-CD和1-MCP的包结配合物，并利用X-射线粉末衍射（X-RPD）、差热分析（DTA）、紫外吸收光谱（UV）、红外吸收光谱（IR）和核磁共振谱（¹H-NMR）等测试方法对此包结物进行了研究。通过比较β-CD和1-MCP形成的包结物在谱图上的差异，证实了包结物的生成。 包结物水溶液与β-CD水溶液的紫外光谱特征有很大差异，包结物在207nm附近出现归属为双键π-π^*跃迁的强吸收带。这表明β-CD与1-MCP之间确实存在着超分子作用。 包结物与β-CD的红外图谱非常相似。但包结物与对应的β-CD相比，O-H键伸缩振动v_S（O-H），C-O键伸缩振动v_S（C-O）和O-H面内弯曲振动δ（O-H）的相对吸收强度Ⅰ均明显发生变化。在包结物中，Ⅰ_v（C-O）与Ⅰ_v（O-H）的差值△Ⅰ₁，Ⅰ_δ（O-H）与Ⅰ_v（C-O）的差值△Ⅰ₂及Ⅰ_v（C-O）／Ⅰ_δ（O-H）分别为4.15，22.1和0.51，而与β-CD相对应的△Ⅰ₁，△Ⅰ₂和Ⅰ_v（C-O）／Ⅰ_δ（O-H）却分别为7.42，56.32和0.12。 热重分析显示包结物在91℃出现一个放热峰，这是客体分子1-MCP克服包结驱动力与β-CD分解而引起的。并且由于主客体分子间的弱相互作用使得β-CD在与1-MCP形成包结物前后的分解失重温度稍有延后（294℃增加到298℃）。 由XRD图可见β-CD在10.62（93％），12.38（100％），17.66（62％），18.84更多还原

【Abstract】 Rapid decline in coriander leaf quality due to postharvest senescence often causes serious commercial losses. Ethylene has been shown to play an important role in senescence of detached leaves. Ethylene gas, a common air pollutant and powerful plant growth regulator is a two-edged sword in the handling perishables. Recent studies have suggested that many crops are affected by exposure to ethylene concentrations as low as a few parts per billion. Luckily, researchers and technologists have developed a number of new approaches to ethylene control using molecular biology, novel chemistries and innovative technologies. It has been found that many compounds can modulate ethylene responses. However, some known inhibitors have certain drawbacks. The compound 1 -methylcyclopropene (1-MCP) has been shown to compete with ethylene for the binding site on the ethylene receptor in plant tissue and to control ethylene responses. Since it is non-toxic and odorless, 1 -MCP is potentially of commercial value to control ethylene-dependent postharvest disorders. Researchers have studied the possible application of 1-MCP to fruits and vegetables. But 1-MCP is discommodious to use in agriculture products because of its resolvability (b.p. 10℃) .β -cyclodextrin (β-CD) is an annular molecule composed of seven glucose units linked by 1,4-glucosidic bonds. The inside the cavity of β-CD is mainly constructed by oxygen atoms and hydrogen atoms of C (3 ) and C (5) . The internal surface of β -CD is hydrophobic. The hydroxyl of the glucose unit is arranged at both ends of the β -CD cavity, so the whole molecule of β-CD is able to form inclusion complexes with a great variety of guest molecules. After complexation, the guest molecules display additional stability against heat, light and oxygen. Accordingly, in recent years, β-CD has aroused great interest and has been successfully and widely utilized in the pharmaceutical and food industries. Moreover, toxicity experiments show that β -CD can be absorbed as a carbohydrate by animal and human bodies. Recent studies about β -CD have shown that there are vast vistas in many fields. The present paper describes the preparation of the inclusion complex of 1 -MCP with β -CD in lab and its investigation by a series of methods in order to provide theoretical data for further applications. At the same time, the stability of 1-MCP isomers was investigated by density functional theory (DFT / B3LYP ) in order to inform the effects of 1 -MCP for inhibiting the ethylene. In this paper, The inclusion complex of 1-methylcyclopropene with β更多还原