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Published on: April 19, 2019
The absolute configuration of (-)-3-hydroxy-alpha-calacorene
Robert D Stipanovic1, Lorraine S Puckhaber, Joseph H Reibenspies
1Southern Plains Agricultural Research Center, Agricultural Research Service, US Department of Agriculture, 2765 F&B Road, College Station, TX 77845, USA. rdstip@cpru.usda.gov
3-Hydroxy-alpha-calacorene, a sesquiterpenoid, was found in cotton and kenaf. Its stereochemistry was analyzed, revealing distinct configurations between Malvaceae and Asteraceae plant sources.
Area of Science:
- Phytochemistry
- Organic Chemistry
- Plant Science
Background:
- Sesquiterpenoids are a diverse class of natural products found in plants.
- 3-Hydroxy-alpha-calacorene is a specific sesquiterpenoid with potential biological activities.
- Cotton (Gossypium hirsutum L.) and kenaf (Hibiscus cannabinus L.) are economically important crops in the Malvaceae family.
Purpose of the Study:
- To identify and characterize 3-hydroxy-alpha-calacorene in cotton and kenaf.
- To compare the stereochemistry of 3-hydroxy-alpha-calacorene from different plant species.
- To determine the absolute configuration of 3-hydroxy-alpha-calacorene from Heterotheca inuloides Cass.
Main Methods:
- Extraction of compounds from plant seedlings.
- High-Performance Liquid Chromatography (HPLC) on a chiral stationary phase column for stereochemical analysis.
- X-ray crystallographic analysis for absolute configuration determination.
Main Results:
- 3-Hydroxy-alpha-calacorene was identified in cold-shocked cotton and kenaf seedlings.
- The compound from cotton and kenaf exhibited the same relative stereochemical configuration.
- 3-Hydroxy-alpha-calacorene isolated from Heterotheca inuloides showed the opposite relative configuration.
- The absolute configuration of 3-hydroxy-alpha-calacorene from H. inuloides was determined as (8R)-(-)-3-hydroxy-alpha-calacorene.
Conclusions:
- Cotton and kenaf synthesize 3-hydroxy-alpha-calacorene with a specific relative configuration.
- Stereochemical differences in 3-hydroxy-alpha-calacorene exist between Malvaceae and Asteraceae species.
- The absolute configuration of the (8R)-(-)-enantiomer provides a reference for further studies on this compound.
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