Phytochemistry of the genus Thapsia
U Rasmussen1, S B Christensen, F Sandberg
1Departments of Pharmacognosy and Chemistry BC, Royal Danish School of Pharmacy, Copenhagen Ø, Denmark.
Planta Medica
|December 1, 1981
Summary
This study analyzed Thapsia (Apiaceae) roots for skin-irritating compounds, discovering new sesquiterpene lactones that are selective histamine liberators. Chemical analysis revealed distinct profiles among Thapsia species.
Area of Science:
- Phytochemistry
- Chemotaxonomy
- Pharmacognosy
Background:
- The genus Thapsia (Apiaceae) is known for producing bioactive secondary metabolites.
- Sesquiterpene lactones and coumarins are key compounds with potential pharmacological activities, including skin irritation.
- Understanding the chemical diversity within Thapsia is crucial for chemotaxonomic classification and drug discovery.
Purpose of the Study:
- To conduct a chemotaxonomic investigation of five Thapsia taxa.
- To isolate and characterize skin-irritating sesquiterpene lactones and specific coumarins from Thapsia root material.
- To identify novel compounds and assess their potential as selective histamine liberators.
Main Methods:
- Chemotaxonomic analysis of root material from five Thapsia taxa.
- Isolation and structural elucidation of sesquiterpene lactones and coumarins using chromatographic and spectroscopic techniques.
- Chemical screening for skin-irritating properties and histamine-releasing activity.
Main Results:
- Eight new tetraesters and two new triesters of hydroxylated C(6)-guaianolides were isolated, including a known compound, trilobolide.
- These compounds represent a novel class of selective histamine liberators.
- Significant chemical variation was observed, particularly in Thapsia villosa, which was divided into four chemotypes. T. garganica differed from T. transtagana.
- Hydroxylated C(6)-guaianolides were found in T. garganica, T. transtagana, T. maxima, and T. villosa chemotypes I and III, but not in T. villosa II and IV or Rouya polygama.
- 6-Methoxy-7-geranyloxycoumarin distribution mirrored that of the guaianolides, while scopoletin was present in all samples.
Conclusions:
- The study established distinct chemical profiles for Thapsia species, aiding in their chemotaxonomic classification.
- New sesquiterpene lactones with selective histamine-releasing properties were identified, offering potential for pharmaceutical development.
- Thapsia villosa exhibits significant chemical heterogeneity, highlighting the importance of detailed chemical analysis for species differentiation.
