Product name: 19-Hydroxybufalin
Synonym name:
Catalogue No.: BP4197
Cas No.: 39844-86-5
Formula: C₂₄H₃₄O₅
Mol Weight: 402.531
Botanical Source: Bufonis Venenum
Type of Compound: Steroids

Purity: 95%~99%
Analysis Method: HPLC-DAD or/and HPLC-ELSD
Identification Method: Mass, NMR
Packing: Brown vial or HDPE plastic bottle

Storage: Store in a well closed container, protected from air and light. Put into refrigerate or freeze for long term storage.
Whenever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20℃. Generally, these will be useable for up to two weeks.

The product could be supplied from milligrams to grams
Inquire for bulk scale.

For Reference Standard and R&D, Not for Human Use Directly.

Storage conditions：Short-term storage at 2~8℃, long-term storage at -20 ~ -80℃

Introduction/Overview

19-Hydroxybufalin is a naturally occurring hydroxylactone with significant biological activity, originally isolated from toad skin secretions. As an important member of the Toad Venolin family, 19-hydroxytoadulin has attracted widespread attention in the field of tumor biology in recent years due to its unique chemical structure and multi-target regulatory capabilities. Numerous studies have shown that this compound not only effectively inhibits tumor cell proliferation but also significantly reduces tumor cell migration and invasion by blocking the epithelial-mesenchymal transition (EMT) process, especially showing good antitumor activity in the prostate cancer PC3 cell line.

This paper aims to systematically review the chemical structure, physicochemical properties, plant origin, and extraction methods of 19-hydroxytode venom, explore its pharmacological activity and mechanism of action in depth, evaluate its druggability and pharmacokinetic characteristics, and look forward to its potential for clinical application. By integrating the latest research advances, it provides theoretical basis and practical guidance for further development and clinical translation of this natural product.

Chemical structure and physicochemical properties

The molecular formula of 19-hydroxytoxin is C_24H_34O_5, with a molecular weight of 402.5310, and it belongs to the toxadiene hydroxytic acid lactone compound. Its chemical structure is based on a typical steroid skeleton, containing multiple hydroxyl and lactone rings, and the introduction of a 19-position hydroxyl group in the structure gives it unique chemical and biological activity characteristics. The compound had a LogP value of 2.4633, indicating moderate lipid solubility, which facilitates cell membrane penetration and distribution in vivo. The topological pole surface area (TPSA) is 90.9 Ų, indicating moderate solubility in polar environments.

Low water solubility (0.0175 mg/mL), which may limit its solubility and bioavailability in aqueous media, but moderate lipid solubility helps it cross biofilms. The high permeability of the blood-brain barrier suggests it may have potential effects on central nervous system diseases. The hERG (cardiac potassium channel) inhibition test results were negative, suggesting that the compound carries a low risk of cardiotoxicity. The Ames mutagenic test scored 0.0, indicating no significant genotoxicity and meeting safety requirements.

Overall, the physicochemical properties of 19-hydroxytophen are suitable for its development as a potential drug molecule, but its water solubility and stability still need to be optimized to enhance its clinical value.

Plant Origins and Extraction Methods

19-hydroxytophenol is mainly found in the skin secretions and venom glands of toads (Bufo genus), with the main sources being the Chinese toad (Bufo gargarizans) and the Brazilian toad (Bufo marinus). Toad toxin compounds serve as defensive secretions of toads, featuring complex biosynthetic pathways and diverse structural types.

Traditional extraction methods typically use organic solvent extraction combined with column chromatography separation. The specific steps include:

1. Sample preparation: Collect fresh toad skin secretions, dry and crush them.
2. Solvent extraction: Multiple extractions using methanol or ethanol yield crude extracts containing Toad Venol.
3. Liquid-liquid distribution: Distributed using solvents of different polarities (such as ethyl acetate, n-hexane) to preliminarily enrich the target component.
4. Chromatographic separation: Using silica gel column chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC) technology, combined with ultraviolet detection and mass spectrometry identification, high-purity 19-hydroxytophen is purified.
5. Structural identification: Confirm its structure using nuclear magnetic resonance (NMR), mass spectrometry (MS), and infrared spectroscopy (IR).

In recent years, with advances in separation technology, supercritical fluid extraction (SFE) and high-efficiency membrane separation techniques have also been introduced, improving extraction efficiency and purity. In addition, the exploration of biosynthesis and semi-synthesis methods has made large-scale preparation possible.

Pharmacological activity research

Research on the pharmacological activity of 19-hydroxytophenol mainly focuses on the antitumor field. It exhibits significant cytotoxicity and inhibitory effects on various tumor cell lines, especially in prostate cancer PC3 cells, effectively inhibiting cell proliferation, migration, and invasion.

Antitumor activity

• Inhibition of cell proliferation: In vitro experiments show that 19-hydroxytophenol can significantly reduce tumor cell proliferation by inducing cell cycle arrest and promoting apoptosis.
• Migration and invasion inhibition: This compound reduces tumor cells' migration and invasion ability by inhibiting the process of epithelial-meselipotent transformation (EMT), thereby decreasing their metastatic potential.
• Induced apoptosis: By regulating the expression of BCL2 family proteins (such as MCL1 and BCL2), mitochondrial pathways are activated, promoting tumor cell apoptosis.
• Anti-angiogenesis: Inhibits HIF1A expression, suppresses angiogenesis in the tumor microenvironment, and restricts tumor nutrient supply.

Other activities

In addition to its antitumor effects, 19-hydroxytophenol also shows certain anti-inflammatory and immunomodulatory activities, possibly mediating improvements in the immune microenvironment by modulating the STAT3 signaling pathway, though related research is still in its early stages.

Mechanism of action and molecular targets

The antitumor mechanism of 19-hydroxytoxin involves multiple signaling pathways and key molecular targets, reflecting its multi-target and multi-mechanism pharmacological characteristics.

Key molecular targets

• MCL1 and BCL2: These two anti-apoptotic proteins are key factors in tumor cells evading programmed death. 19-Hydroxytophenol disrupts the intracellular anti-apoptotic balance by downregulating the expression of MCL1 and BCL2, thereby promoting apoptosis.
• STAT3: As an important transcription factor for tumor cell proliferation, survival, and immune escape, inhibition of STAT3 helps block tumor signaling and immunosuppression.
• MMP2: Matrix metalloproteinase 2 participates in extracellular matrix degradation, promoting tumor cell invasion. 19-Hydroxytophenol reduces cell migration by inhibiting MMP2 activity.
• TOP1 and TOP2A :D NA Topoisomerases I and II are important enzymes for DNA replication and transcription; inhibiting their activity can block tumor cell proliferation.
• HIF1A: Hypoxia-inducing factor 1α regulates tumors' ability to adapt to hypoxic environments; inhibiting HIF1A can limit tumor angiogenesis.
• MAPK1: Mitogen-activated protein kinase 1 is involved in cell proliferation and differentiation signal transduction; its regulation by 19-hydroxytophenol helps inhibit tumor growth.
• ESR1 and CYP19A1: estrogen receptor α and aromatase are important targets for hormone-dependent tumors. 19-Hydroxytophenol may exert auxiliary antitumor effects by modulating hormone signaling pathways.

Overview of the mechanism of action

19-Hydroxytotoxin Venolin co-regulates tumor cell proliferation, apoptosis, migration, and invasion through multiple targets, blocking the EMT process and inhibiting angiogenesis and immune escape in the tumor microenvironment. Its mechanism of action involves intracellular signal transduction, gene expression regulation, and protease activity regulation, reflecting the complex pharmacological network of natural products.

Druggability evaluation and pharmacokinetics

Efficacy evaluation

The physicochemical properties of 19-hydroxytoxin show moderate lipid solubility and high blood-brain barrier permeability, making it suitable for oral administration or injection. It has no significant hERG inhibitory or genotoxicity, and is relatively safe. TPSA values suggest its potential in cell membrane penetration and targeted tissue distribution.

However, its low water solubility may limit its bioavailability, and drug formulation technologies (such as nanocarriers and liposome encapsulation) are needed to improve solubility and stability. Additionally, batch differences and complex structures of natural products pose challenges to quality control, necessitating the establishment of strict standardized production processes.

Pharmacokinetics

Currently, pharmacokinetic research on 19-hydroxytophenol is relatively limited. Preliminary in vivo experiments have shown that this compound has a long half-life in the blood, allowing effective distribution to tumor tissue and the central nervous system. Its high blood-brain barrier permeability offers potential for treating brain tumors.

Metabolic pathways may involve the hepatic cytochrome P450 enzyme system, especially CYP19A1-related metabolism, suggesting potential interactions related to hormone metabolism. Excretion mainly occurs via the kidneys and bile pathways, and further studies are needed on the activity and toxicity of its metabolic products.

Prospects and outlooks for clinical applications

As a multi-target antitumor natural product, 19-hydroxytophenol has the potential to become a novel anticancer drug. Its unique advantages in inhibiting tumor cell migration, invasion, and EMT processes make it especially suitable for highly invasive tumor types with high metastasis risk, such as prostate cancer and breast cancer.

The key to future clinical applications lies in:

• Dosage Form Optimization: Improve water solubility and bioavailability to develop formulations suitable for clinical use.
• Safety Assessment: Systematic toxicological studies to ensure long-term medication safety.
• Clinical trial design: Conduct Phase I to III clinical trials to verify efficacy and safety.
• Combination therapy strategy: Combine existing chemotherapy, targeted therapy, or immunotherapy to enhance overall treatment outcomes.
• Biomarker development: Based on their targets, biomarkers that predict efficacy and resistance are screened to enable precise drug administration.

Moreover, with the development of synthetic biology and medicinal chemistry, optimizing the pharmacodynamic and pharmacokinetic properties of 19-hydroxytophenol through structural modification and semi-synthetic methods will greatly promote its clinical translation.

Conclusion

As an important natural product of the Toad Venoxing family, 19-hydroxytoadoxin shows broad prospects for drug development thanks to its unique chemical structure and multi-target antitumor mechanism. Current research has preliminarily revealed its key role in tumor suppression, migration blockade, and apoptosis induction, but further exploration of its pharmacokinetic characteristics and clinical safety is still needed.

In the future, through multidisciplinary collaboration and modern drug development technologies, 19-hydroxytophen is expected to become an innovative drug in the field of anti-tumor therapy, bringing new treatment options and hope to cancer patients.