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首页> 外文期刊>Spectrochimica acta, Part A. Molecular and biomolecular spectroscopy >Structure investigation of codeine drug using mass spectrometry, thermal analyses and semi-emperical molecular orbital (MO) calculations
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Structure investigation of codeine drug using mass spectrometry, thermal analyses and semi-emperical molecular orbital (MO) calculations

机译：可待因药物的结构研究，采用质谱，热分析和半经验分子轨道（MO）计算

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Codeine is an analgesic with uses similar to morphine, but it has a mild sedative effect. It is preferable used as phosphate form and it is often administrated by mouth with aspirin or paracetamol. Therefore, it is important to investigate its structure to know the active groups and weak bonds responsible for its medical activity. Consequently in the present work, codeine was investigated by mass spectrometry and thermal analyses (TG, DTG and DTA) and confirming by semi-empirical MO-calculation (PM3 method) in the neutral and positively charged forms of the drug. Some results of studying the d-block element complexes of codeine were used to declare the relationship between drug structure and its chemical reactivity in vitro system. The mass spectra and thermal analyses fragmentation pathways were proposed and compared to each other to select the most suitable scheme representing the correct fragmentation of this drug. From EI mass spectra, the main primary cleavage site of the charged drug molecule is that due to beta-cleavage to nitrogen atom in its skeleton. It occurs in two parallel mechanisms with the same possibility, i.e. no difference in appearance activation energy between them. In the neutral drug form the primary site cleavage is that occurs in the ether ring. Thermal analyses of the neutral form of the drug revealed the high response of the drug to the temperature variation with very fast rate. It decomposed in several sequential steps in the temperature range 200-600 degrees C. The initial thermal fragments are very similar to that obtained by mass spectrometric fragmentation. Therefore, comparison between mass and thermal helps in selection of the proper pathway representing the fragmentation of this drug. This comparison successfully confirmed by MOC. These calculations give the bond order, charge distribution, heat of formation and possible hybridization of some atoms in different position of the drug skeleton. This helps the successful choice of the weakest bond at which both mass and thermal fragmentation occurs. Therefore, the best fragmentation pathway of this drug is correctly selected. The effect of such fragmentation on the drug behavior in the human body can be expected as a result of comparing these data with that obtained on studying codeine metal complexes using mass and thermal fragmentation techniques. (c) 2005 Elsevier B.V. All rights reserved.
机译：可待因是一种与吗啡相似的镇痛药，但具有轻度的镇静作用。优选以磷酸盐形式使用，并且通常与阿斯匹林或扑热息痛经口给药。因此，重要的是研究其结构以了解负责其医学活性的活性基团和弱键。因此，在本工作中，通过质谱和热分析（TG，DTG和DTA）研究了可待因，并通过半经验MO计算（PM3方法）确定了药物的中性和正电荷形式。研究可待因的d-嵌段元素复合物的一些结果被用于声明药物结构与其体外化学反应性之间的关系。提出了质谱和热分析的裂解途径，并将其相互比较以选择最合适的方案来代表该药物的正确裂解。从EI质谱图中，带电药物分子的主要主要裂解位点是由于其骨架中的β裂解为氮原子而引起的。它在两个平行机制中以相同的可能性发生，即它们之间的外观激活能没有差异。在中性药物形式中，主要位点裂解是发生在醚环中。对药物中性形式的热分析表明，药物对温度变化的响应速度非常快。在200-600摄氏度的温度范围内，它在几个连续的步骤中分解。初始热碎片与质谱碎裂获得的碎片非常相似。因此，质量和热之间的比较有助于选择代表该药物片段化的适当途径。这项比较得到了交通部的确认。这些计算给出了键序，电荷分布，形成热以及药物骨架不同位置上某些原子的可能杂化。这有助于成功选择发生质量碎裂和热碎裂的最弱键。因此，正确选择了该药物的最佳裂解途径。通过将这些数据与使用质量和热裂解技术研究可待因金属配合物获得的数据进行比较，可以预期这种裂解对人体药物行为的影响。 （c）2005 Elsevier B.V.保留所有权利。

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