A comprehensive review on phytochemistry and pharmacology of genus Kopsia: monoterpene alkaloids - major secondary metabolites

Asymmetric Synthesis of Arboduridine

The first asymmetric total synthesis of the monoterpenoid indole alkaloid arboduridine has been accomplished. The tricyclic A/B/D ring system was constructed by an enantioselective Michael reaction followed by intramolecular nucleophilic addition. Intramolecular α-amination of a ketone forged the piperidine ring, while a Horner-Wadsworth-Emmons (HWE) reaction was used to form the pyrrolidine ring. A reduction cyclization cascade led to formation of the tetrahydrofuran ring.

Wedelolactone: A molecule of interests

BACKGROUND

The search for bioactive molecules from medicinal plants of the family Asteraceae has been one of the targets in various phytochemical and pharmacological investigations for many years. According to these studies, wedelolactone, a coumestan of the secondary metabolite type, is a key compound found in several Eclipta and Wedelia herbal plants. To date, numerous experimental studies with intention of highlighting its role in drug development programs were carried out, but an extensive review is not sufficient.

OBJECTIVE

The current review aims to fill the gaps in extensive knowledge about phytochemistry, synthesis, pharmacology, and pharmacokinetics of coumestan wedelolactone.

MATERIALS AND METHODS

The databases Google Scholar, Scopus, PubMed, Web of Science, Science Direct, Medline, and CNKI were used to compile the list of references. In order to find references, "wedelolactone" was considered separately or in combination with "phytochemistry", "synthesis", "pharmacology", and "pharmacokinetics." Since the 1950s, >100 publications have been collected and reviewed.

RESULTS

Wedelolactone is likely to be a characteristic metabolite of two genera Eclipta and Wedelia, the family Asteraceae, while it could be synthetically derived from mono-phenol derivatives, through Sonogashira and cross-coupling reactions. Numerous biomedical investigations on wedelolactone revealed that its pharmacological values included anticancer, antiinflammatory, antidiabetic, antiobesity, antimyotoxicity, antibacterial, antioxidant, antivirus, anti-aging, cardiovascular, serine protease inhibition, especially its protective health benefits to living organs such as liver, kidney, lung, neuron, eye, bone, and tooth. The combination of wedelolactone and potential agents is a preferential approach to improve its biomedical values. Pharmacokinetic study exhibited that wedelolactone was metabolized in rat plasma due to hydrolysis, open-ring lactone, methylation, demethylation, and glucuronidation.

CONCLUSIONS

Wedelolactone is a promising agent with the great pharmacological values. Molecular mechanisms of the actions of this compound at both in vitro and in vivo levels are now available. However, reports highlighting biosynthesis and structure-activity relationship are still not adequate. Moreover, chemo-preventive records utilizing nano-technological approaches to improve its bioavailability are needed since the solubility in the living body environment is still limited.