Thalidasine (Bisbenzylisoquinoline Alkaloid · Anti-angiogenic · Research Reference)
| Compound | Thalidasine (Thalictrum bisbenzylisoquinoline alkaloid) |
| Class | Alkaloid — Bisbenzylisoquinoline (BBIQ) |
| CAS | Not universally assigned (structure-verified isolate) |
| Molecular formula | C₃₇H₄₀N₂O₇ (approximate, varies by specific isomer) |
| Primary sources | Thalictrum dasycarpum (purple meadow rue), Thalictrum minus |
| Plant part | Roots, rhizomes |
| Claim strength | Emerging |
| Key applications | Anti-angiogenic research; alkaloid structure-activity reference; informational-only |
| Buy from Herbuno | Informational reference — see HerbIQ Compound Index → |
Name origin: Thalidasine is named after Thalictrum dasycarpum (thalictr- from Thalictrum genus; dasine from dasycarpum), the primary plant source from which it was isolated. It belongs to the bisbenzylisoquinoline (BBIQ) alkaloid class — dimeric structures formed by oxidative coupling of two benzylisoquinoline monomer units, the same structural class as tubocurarine (curare), tetrandrine, and fangchinoline. Traditional use: Thalictrum species have extensive traditional use across Indigenous North American, Chinese, and European herbal medicine — primarily for fever, jaundice, and skin conditions. Thalictrum dasycarpum specifically was used by several Indigenous North American tribes as a treatment for sores, fevers, and as a ceremonial plant. The alkaloid fraction is responsible for observed bioactivities, though thalidasine as a specific compound was not traditional knowledge. Research trajectory: Thalidasine attracted attention in the 1980s–1990s for anti-angiogenic activity — inhibiting blood vessel formation at concentrations relevant to oncology research. Interest waned with the advent of VEGF-targeted biologics but has been revisited with structure-activity studies of BBIQ alkaloids. Safety context: Thalidasine is not a controlled substance. Thalictrum alkaloids as a class have variable toxicity; professional handling of concentrated alkaloid extracts is advisable.
Pharmacological Profile of Thalidasine
Anti-angiogenic activity: Thalidasine inhibits endothelial cell proliferation and tube formation in in vitro angiogenesis assays at low micromolar concentrations. In the chick chorioallantoic membrane (CAM) model — a standard ex vivo angiogenesis screen — thalidasine reduces vascular density at doses of 5–25 μg/egg. The mechanism is not fully characterised but appears to involve interference with VEGF receptor signalling and endothelial cytoskeletal reorganisation. Claim strength: Emerging.
Cytotoxic activity: Thalidasine shows cytotoxic activity against multiple cancer cell lines at 1–20 μM concentrations in MTT assays. The mechanism involves cell cycle arrest and apoptosis induction; selectivity for cancer versus normal cell types has been demonstrated in some studies but not consistently. Claim strength: Emerging.
Structural comparison with tubocurarine: Thalidasine shares the BBIQ scaffold with tubocurarine — the classic curare neuromuscular blocker. Unlike tubocurarine (which is a bis-quaternary ammonium compound), thalidasine retains tertiary amine groups and therefore crosses the blood-brain barrier more readily. The neuromuscular blocking liability of thalidasine has not been systematically characterised. Claim strength: Emerging.
Antimicrobial: Activity against Mycobacterium tuberculosis and several antibiotic-resistant Gram-positive organisms has been reported for Thalictrum alkaloid fractions containing thalidasine. Isolated thalidasine MIC data are limited. Claim strength: Emerging.
This compound is documented for research and formulator education purposes. For commercially available botanical ingredients, explore the HerbIQ Compound Index →
Regulatory and Formulator Context
Thalidasine is not a controlled substance. Thalictrum dasycarpum is not a regulated plant in most jurisdictions. However, the concentration of BBIQ alkaloids in Thalictrum root extracts, and the potential for neuromuscular effects at high alkaloid loads, means that concentrated root extracts should be handled with appropriate professional caution.
No supplement, food, or cosmetic application exists for thalidasine. Its anti-angiogenic and cytotoxic activities are in the range that makes it a research compound rather than a supplement ingredient — and the lack of human safety data precludes consumer product development.
Thalictrum species alkaloids are of ongoing interest in natural product drug discovery for anti-angiogenic and anti-cancer applications, as alternatives to biologics for specific cancer types. The BBIQ scaffold represents a chemically tractable structure for semi-synthetic optimisation.
This entry completes HerbIQ's documentation of the bisbenzylisoquinoline alkaloid class alongside tetrandrine, fangchinoline, dauricine, and related compounds built in earlier batches.
Frequently Asked Questions — Thalidasine
What is the bisbenzylisoquinoline (BBIQ) alkaloid class?
BBIQs are dimeric isoquinoline alkaloids formed by oxidative coupling of two BTIQ monomers via ether or direct C-C bonds. The class includes tubocurarine (neuromuscular blocker from curare), tetrandrine and fangchinoline (Stephania tetrandra — anti-inflammatory, antihypertensive), dauricine (Menispermum dauricum — antiarrhythmic), and thalidasine. The dimer linkage type (head-to-head, tail-to-tail, or mixed) and quaternisation state determine pharmacological class.
What makes thalidasine interesting for anti-angiogenic research?
Natural product anti-angiogenics that work via mechanisms distinct from VEGF pathway blockade are of significant pharmaceutical interest — particularly for tumour types that develop resistance to bevacizumab and similar biologics. Thalidasine's anti-angiogenic activity at low micromolar concentrations, combined with its distinct BBIQ scaffold, makes it a useful pharmacophore reference for structure-activity optimisation.
Is Thalictrum (meadow rue) available as a commercial herbal extract?
Thalictrum minus and T. flavum are used in European and Chinese herbal medicine, with limited commercial extract availability. T. dasycarpum (North American species) has no significant commercial extract market. The genus is characterised primarily in research settings; formulator access to Thalictrum alkaloids is through specialist botanical and research chemical suppliers rather than mainstream herbal extract catalogues.
How does thalidasine compare to tetrandrine from the same BBIQ class?
Tetrandrine (from Stephania tetrandra — Han Fang Ji) is the commercially developed BBIQ with product-live status in the Herbuno catalogue and multiple clinical/preclinical studies for anti-inflammatory, antihypertensive, and antifibrotic applications. Thalidasine is a research-stage BBIQ with narrower characterisation and no commercial product development. The comparison illustrates the range from research alkaloid (thalidasine) to clinically studied commercial extract constituent (tetrandrine) within the same alkaloid class.
Related compounds: Tetrandrine, Fangchinoline, Dauricine, Isochondodendrine
Claim-strength scale – High = multiple human RCTs; Moderate = limited trials or strong preclinical convergence; Emerging = early-stage lab or animal data.
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