Related Experiment Video
Updated: Jul 7, 2026

Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade
Published on: August 14, 2019
A new chlorine-containing flavanol and four new phenylpropanoids from Toddalia asiatica
Bing-Ying Zheng1, Zhan-Tao Zhao1, Feng Wu1
1School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China.
Abstract:
A rare chlorine-containing flavanol, chlorotoddalianone A (1), together with four new phenylpropanoids, toddaliaphenols A-D (2-5) and six known compounds (6-11) were obtained from the foliage and branches of Zanthoxylum asiaticum (L.) Appelhans, Groppo & J.Wen (syn. Toddalia asiatica (L.) Lam.). Their chemical structures and absolute configurations were elucidated through extensive spectroscopic analyses, including 1D and 2D NMR, HRESIMS and ECD calculation. Notably, compound 1 possesses an unusual structural framework, featuring a chlorinated 2,2-dimethylpyran unit linearly fused to the epicatechin A-ring. Biological evaluation of these isolates was conducted utilising an LPS-activated RAW 264.7 macrophage model to assess their impact on NO production. Compound 1 emerged as a moderate anti-inflammatory inhibitor (IC50 value = 20.96 ± 1.84 μM). Given its lack of evident cytotoxicity, chlorotoddalianone A represents a promising candidate for further anti-inflammatory research.
Related Concept Videos
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Alkyl Halides
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
Five-Membered Heterocyclic Aromatic Compounds: Overview
Preparation of Diols and Pinacol Rearrangement
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
Electrophilic Aromatic Substitution: Chlorination and Bromination of Benzene
Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
