阿斯特拉康登萨托尔D:来自Astragalus condensatus的A 6/6/5/6循环阿尔坦三化物
Fadime Aydoğan1,2, Pankaj Pandey1, Frank R Fronczek3
1National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, Mississippi 38677, United States.
Organic letters
|March 12, 2025
概括
从Astragalus condensatus中分离出了四种新的五环三类化合物,包括阿斯特拉康登萨托尔D. 它们的结构使用NMR,DP4+计算和X射线晶体学得到证实,并提出了生物合成途径.
科学领域:
- 自然产品化学 自然产品化学
- 有机化学 有机化学
- 植物化学 植物化学
背景情况:
- 阿斯特拉加勒斯凝结物是生物活性化合物的植物来源.
- 五环三烯酸具有多样化的生物活动.
- 新型天然产品的结构阐明对于药物发现至关重要.
研究的目的:
- 从Astragalus condensatus中分离和描述新的化合物.
- 确定分离化合物的绝对立体结构.
- 为新型化合物提出并计算支持生物合成途径.
主要方法:
- 使用色谱技术分离化合物.
- 通过核磁共振 (NMR) 光谱学阐明结构.
- 使用NMR,DP4+计算和X射线晶体学来确定绝对立体化学.
主要成果:
- 他们分离了四种化合物,包括阿斯特拉康登萨托尔D (1),它的前体 (2),以及两个衍生物 (3和4).
- 所有四种化合物的绝对立体结构都被明确确定.
- X射线结晶学证实了化合物3的结构.
- 提出了一种可能的生物合成途径,涉及瓦格纳-米尔韦恩重组和逆阿尔多尔反应,并得到了计算分析的支持.
结论:
- 该研究报告了首次从Astragalus condensatus中分离出Astracondensatol D和相关化合物.
- 先进的光谱和计算方法使得最终的结构确定成为可能.
- 拟议的生物合成途径提供了关于这些复杂的三烯酸的形成的见解.
相关概念视频
01:18Aromatic Hydrocarbon Cations: Structural Overview
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Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group...
Removing one hydrogen from the intervening CH2 group...
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02:29Conformations of Cycloalkanes
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Adolf von Baeyer attempted to explain the instabilities of small and large cycloalkane rings using the concept of angle strain — the strain caused by the deviation of bond angles from the ideal 109.5° tetrahedral value for sp3 hybridized carbons. However, while cyclopropane and cyclobutane are strained, as expected from their highly compressed bond angles, cyclopentane is more strained than predicted, and cyclohexane is virtually strain-free. Hence, Baeyer’s theory that...
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02:28Cycloalkanes
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Cycloalkanes are saturated cyclic hydrocarbons with carbon atoms arranged in the form of rings. They have two fewer hydrogen atoms than the corresponding acyclic alkane; therefore, their general formula is CnH2n. The structural formulas of cycloalkanes are simplified using the line-angle representation. The regular polygons are used to represent the cycloalkane rings, with each side representing a carbon-carbon bond.
The IUPAC nomenclature of cycloalkanes follows similar rules that apply to...
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01:18Aromatic Hydrocarbon Anions: Structural Overview
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Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous...
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01:18Frost Circles for Different Conjugated Systems
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02:11Conformations of Cyclohexane
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