Amide alkaloids from Scopolia tangutica

Area of Science:

• Phytochemistry
• Pharmacology

Background:

• Scopolia tangutica is a plant source of various alkaloids.
• The chemical constituents of S. tangutica roots are not fully elucidated, particularly regarding hydroxycinnamic acid amides.

Purpose of the Study:

• To isolate and identify new chemical compounds from Scopolia tangutica roots.
• To investigate the pharmacological activity of the isolated compounds, specifically their interaction with opioid receptors and analgesic effects.

Main Methods:

• Phytochemical investigation involving extraction and isolation techniques.
• Structural elucidation of new compounds using spectroscopic methods.
• In vitro assay for µ-opioid receptor agonism.
• In vivo analgesic testing using the tail-flick assay in mice, with naloxone as a reversal agent.

Main Results:

• Four new hydroxycinnamic acid amides (scotanamines A-D) and seven known alkaloids were isolated.
• Compound 1 features a unique structure derived from nortropinone and putrescine.
• Compound 2 demonstrated moderate µ-opioid receptor agonist activity (EC50=7.3 µM).
• Compound 2 induced analgesia in mice, which was antagonized by naloxone.

Conclusions:

• The study expands the known chemical diversity of Scopolia tangutica, identifying novel hydroxycinnamic acid amides.
• Compound 2 represents a potential lead for analgesic drug development due to its µ-opioid receptor activity and in vivo efficacy.
• The findings highlight the pharmacological relevance of secondary metabolites from S. tangutica.