Related Experiment Video
Updated: May 6, 2026
08:56
Transient Expression in Nicotiana Benthamiana Leaves for Triterpene Production at a Preparative Scale
Published on: August 16, 2018
18.3K
Cycloartane triterpenes from Beesia calthaefolia (Maxim.)
Li-Hua Mu1, Hong-Jie Li2, Dai-Hong Guo1
1Department of Clinical Pharmacology, General Hospital of PLA, Beijing 100853, China.
Fitoterapia
|October 23, 2013
Summary
Beesia calthaefolia yielded new cycloartane triterpenoids. Compound 4 demonstrated potent complement system inhibition, outperforming Rosmarinic acid.
Area of Science:
- Natural Product Chemistry
- Immunology
- Pharmacology
Background:
- Beesia calthaefolia is a plant source of bioactive compounds.
- The complement system plays a crucial role in innate immunity.
- Cycloartane triterpenoids are a class of natural products with diverse biological activities.
Purpose of the Study:
- To isolate and characterize new cycloartane triterpenoids from Beesia calthaefolia.
- To evaluate the inhibitory effects of these compounds on the classical pathway of the complement system.
Main Methods:
- Isolation of compounds using chromatographic techniques.
- Structure elucidation using 1D and 2D NMR, HRESIMS, and optical rotation.
- In vitro assay for complement system inhibition (classical pathway).
Main Results:
- Three new cycloartane triterpenoids (1-3) and two known compounds (4, 5) were isolated.
- Compound 4 exhibited significant inhibitory activity against the classical complement pathway (IC50 136.7 μM), surpassing the positive control Rosmarinic acid (IC50 181.8 μM).
- Compounds 2 and 3 showed moderate inhibitory activity (IC50 206 μM and 200.9 μM, respectively).
Conclusions:
- Beesia calthaefolia is a valuable source of novel cycloartane triterpenoids.
- Compound 4 represents a promising lead for developing complement inhibitors.
- Further investigation into the mechanism of action and structure-activity relationships is warranted.
Related Concept Videos
01:18Aromatic Hydrocarbon Cations: Structural Overview
3.5K
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...
3.5K
02:29Conformations of Cycloalkanes
12.3K
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...
12.3K
01:05Mass Spectrometry: Cycloalkane Fragmentation
2.3K
In mass spectrometry, cycloalkanes exhibit distinct fragmentation patterns due to the inherent stability of their molecular ions compared to linear or branched alkanes. The ring structure of cycloalkanes provides additional stability to the molecular ions, often resulting in prominent ion peaks in the mass spectrum.
For example, cyclohexane molecular ions have a mass-to-charge ratio (m/z) of 84, which tends to produce a stronger signal than linear alkanes like hexane. This stability comes from...
For example, cyclohexane molecular ions have a mass-to-charge ratio (m/z) of 84, which tends to produce a stronger signal than linear alkanes like hexane. This stability comes from...
2.3K
02:28Cycloalkanes
14.2K
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...
The IUPAC nomenclature of cycloalkanes follows similar rules that apply to...
14.2K
01:18Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism
2.0K
Birch reduction uses solvated electrons as reducing agents. The reaction converts benzene to 1,4-cyclohexadiene. The reaction proceeds by the transfer of a single electron to the ring to form a benzene radical anion. This anion is highly basic—it abstracts a proton from the alcohol to form a cyclohexadienyl radical. Another single electron transfer gives the cyclohexadienyl anion. A proton transfer from the alcohol forms 1,4-cyclohexadiene. Since this reduction occurs via radical anion...
2.0K
02:37Disubstituted Cyclohexanes: cis-trans Isomerism
10.9K
Depending upon the different spatial orientation of the substituents, the disubstituted cycloalkanes exhibit two types of stereoisomers. The cis isomers have the substituents on the same side of the ring, whereas the trans isomers have the substituents on the opposite sides. These stereoisomers exhibit different physical properties and cannot be interconverted without breaking the carbon-carbon bonds.
In cyclohexane, the substituents can occupy different positions generating distinct isomers....
In cyclohexane, the substituents can occupy different positions generating distinct isomers....
10.9K