Related Experiment Video
Updated: Jun 28, 2026
10:17
Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Two new isomeric alpha-tetralones from Pyrola calliantha
Yi-Lei Chen1, Chang-Heng Tan, Jun-Jie Tan
1State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Science, Chinese Academy of Sciences, Shanghai, P. R. China.
Planta Medica
|November 11, 2008
Summary
Two new isomeric alpha-tetralones, Callianthones A and B, were isolated from Pyrola calliantha. Their structures and absolute configurations were determined using spectral analysis, including 2D NMR and CD spectra.
Area of Science:
- Natural Products Chemistry
- Organic Chemistry
- Phytochemistry
Background:
- Pyrola calliantha is a plant species known for its potential medicinal properties.
- Isolation and characterization of novel compounds from natural sources are crucial for drug discovery and understanding chemical diversity.
Purpose of the Study:
- To isolate and characterize new chemical constituents from the 50% EtOH extract of Pyrola calliantha.
- To determine the structures and absolute configurations of the newly isolated compounds.
Main Methods:
- Extraction of Pyrola calliantha using 50% ethanol.
- Isolation of compounds using chromatographic techniques.
- Structure elucidation using spectral analysis, including 2D NMR and Circular Dichroism (CD) spectroscopy.
- Determination of absolute configurations through model studies and CD spectra.
Main Results:
- Two new isomeric alpha-tetralones, designated Callianthones A (1) and B (2), were isolated.
- A known alpha-tetralone (3) and four known flavonoids (4-7) were also identified.
- The structures were determined to be (2S,4R)- and (2S,4S)-2,4-dihydroxy-2,7-dimethyl-3,4-dihydronaphthalen-1(2H)-one for Callianthones A and B, respectively.
Conclusions:
- The study successfully identified and characterized two novel alpha-tetralone isomers from Pyrola calliantha.
- The findings contribute to the chemical knowledge of the Pyrola genus and provide potential leads for further pharmacological investigation.
More Related Videos
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
Related Concept Videos
01:18Aromatic Hydrocarbon Cations: Structural Overview
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 with both...
Removing one hydrogen from the intervening CH2 group with both...
02:18Constitutional Isomers of Alkanes
Organic compounds of the same molecular formula can have different structural formulas called constitutional isomers, and the phenomenon is known as constitutional isomerism. Alkanes with four or more carbons showing multiple structures with the same molecular formula thereby exhibit constitutional isomerism.
The linear isomer of an alkane is prefixed by the term “n”; hence a linear isomer of pentane is known as n-pentane. Based on the type of branching, some of the branched isomers are given...
The linear isomer of an alkane is prefixed by the term “n”; hence a linear isomer of pentane is known as n-pentane. Based on the type of branching, some of the branched isomers are given...
01:13Five-Membered Heterocyclic Aromatic Compounds: Overview
Heterocyclic aromatic compounds are cyclic compounds that are aromatic and have one or more heteroatoms—atoms other than carbon, in the ring. Depending upon the number of atoms present in the ring, they can be either five or six-membered. Examples of five-membered heterocyclic aromatic compounds include pyrrole, furan, thiophene, and imidazole. Pyrrole consists of one nitrogen atom having one lone pair of electrons. Furan and thiophene have one oxygen and one sulfur heteroatom, respectively.
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
01:07Radicals: Electronic Structure and Geometry
This lesson delves into the geometry of a radical, which is influenced by the electronic structure of the molecule. The principle is similar to that of a lone pair, where the unpaired electron influences the geometry at the radical center.
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
02:33Stereoisomerism of Cyclic Compounds
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...