Synonym name: 5-Hydroxy-4',6,7,8-tetramethoxyflavone; 5-O-Demethyltangeretin; 5-Desmethyltangeretin
Catalogue No.: BP0624
Cas No.: 2798-20-1
Formula: C₁₉H₁₈O₇
Mol Weight: 358.346
Botanical Source: the peel of Citrus sinensis (orange) and Citrus jambhiri. Also from Gardenia lucida, Brickellia spp. and Mentha spp.

Purity: 95%~99%
Analysis Method: HPLC-DAD or/and HPLC-ELSD
Identification Method: Mass, NMR
Packing: Brown vial or HDPE plastic bottle
Can be supplied from milligrams to grams.

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

HPLC of Gardenin B

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

Introduction/Overview

Gardenin B is a typical methoxyflavonoid natural product, and due to its unique structure and diverse bioactivity, it has attracted widespread attention in the field of natural product pharmacology in recent years. As an important member of flavonoid compounds, Gardenia Flavin B not only exhibits significant antioxidant properties but also demonstrates good antitumor activity, especially in models of malignant tumors such as liver cancer. Its mechanism of action involves inhibition of various cell signaling pathways and key enzymes, such as USP7, ODC, and Cathepsin D, demonstrating multiple effects in regulating the cell cycle, inducing apoptosis, and inhibiting tumor cell proliferation. This paper aims to systematically review the chemical structure, origin, pharmacological activity, mechanism of action, and druggability evaluation of Gardenia flavin B, explore its clinical application prospects, and provide scientific evidence for subsequent drug development and mechanistic studies.

Chemical structure and physicochemical properties

Gardenia flavin B has the molecular formula C20H18O6, molecular weight 358.3460, and CAS number 2798-20-1. Its structural core is a typical flavonoid backbone, containing multiple methoxy substituents, giving it high lipid solubility and stability. The LogP value is 2.5607, indicating moderate hydrophobicity, which is beneficial for cell membrane penetration. The polar surface area (TPSA) is 87.3600, indicating that its molecules have certain polarity, which helps bind to biological macromolecules. Its low water solubility (0.0087) suggests limited solubility in the aqueous phase, but this can be improved to some extent through pharmaceutical formulation technology. The blood-brain barrier has low permeability, reducing the risk of central nervous system side effects. The hERG channel inhibition test was negative, indicating a low risk of cardiotoxicity. The Ames-induced mutagenic test value was 1.2, indicating a low genotoxicity risk and a solid safety foundation.

The chemical structure of gardenia flavin B is shown in Figure 1. In the typical tricyclic structure of flavonoids, methoxy modifications at C-6 and C-8 positions give it unique biological activity. The hydroxyl and methoxy groups within the molecule interact through hydrogen bonding and hydrophobicity, affecting their affinity and selectivity for binding to target proteins.

Plant Origins and Extraction Methods

Gardenia flavonin B is mainly found in gardenias (Gardenia jasminoides Ellis) and other gardeniform plants, and is an important representative of flavonoid components in these plants. As a traditional Chinese medicinal herb, gardenia is widely distributed in southern China and Southeast Asia, and its fruits and leaves are rich in gardenia flavin B.

The extraction process usually uses organic solvent extraction methods. Using dried gardenia fruit as raw material, it is first crudely extracted with ethanol or methanol, then separated and purified through liquid-liquid separation and column chromatography techniques (such as silica gel column chromatography, inverse-phase high-performance liquid chromatography, etc.). In recent years, the application of ultrasound-assisted extraction and microwave-assisted extraction technologies has significantly improved extraction efficiency and purity. The purified gardenia flavin B was structurally identified using mass spectrometry (MS), nuclear magnetic resonance imaging (NMR), and other methods.

Optimizing the extraction process not only increases yield but also ensures the stability of active ingredients, laying the foundation for subsequent pharmacological research and drug development.

Pharmacological activity research

Antioxidant activity

Gardenia flavin B exhibits significant antioxidant capacity. In vitro DPPH radical scavenging experiments, its IC50 was 8.87 μg/mL, demonstrating strong free radical scavenging ability. Additionally, in nitric oxide (NO) radical scavenging experiments, the IC50 was 10.59 μg/mL, further confirming its antioxidant effect. Its iron ion reduction ability is also strong, suggesting it can alleviate oxidative stress through multiple pathways and protect cells from oxidative damage.

Antitumor activity

Gardenia flavin B exhibits proliferation-inhibiting activity in various tumor cell lines, especially prominent in liver cancer cells. In vitro experiments show that gardenia flavin B can induce cell cycle arrest in tumor cells, block the progression of the cell cycle, and inhibit cell proliferation. At the same time, it can activate intracellular apoptotic pathways, promoting programmed tumor cell death.

Additionally, gardenia flavin B inhibits key enzymes such as USP7 (ubiquitin-specific protease 7), ODC (ornithine decarboxylase), and Cathepsin D, with IC50s of 6.24 μg/mL and 5.61 μg/mL, respectively, demonstrating its potential for multi-target regulation. These enzymes play important roles in tumor cell proliferation, migration, and invasion. Gardeniflavin B intervenes in tumor cell biological behavior by inhibiting these targets.

Anti-inflammatory and immunomodulatory

Some studies have shown that gardenia flavin B can inhibit the release of inflammatory mediators and reduce inflammatory responses, suggesting its potential application in tumor microenvironment regulation and immunotherapy. Its regulation of inflammation-related targets such as PTGS2 (COX-2) may help suppress tumor-related inflammation and improve treatment outcomes.

Mechanism of action and molecular targets

The antitumor mechanism of gardenia flavin B involves multiple signaling pathways and molecular targets, mainly including:

1. Regulates apoptosis-related proteins
   Gardenia flavin B can regulate the expression of BCL2 family proteins, reduce the level of the anti-apoptotic protein BCL2, promote the activation of apoptotic proteins, and induce apoptosis in tumor cells. By activating mitochondrial pathways, cytochrome C is released, initiating a cascade of caspase activation and completing programmed cell death.

2. Suppression of the STAT3 signaling pathway
   As a key pro-cancer signaling molecule in various tumors, STAT3's activity is effectively inhibited by gardeniflavin B, blocking tumor cell proliferation and survival signals, and suppressing tumor growth and metastasis.

3. Impacting MAPK/ERK pathways
   Gardenia flavin B regulates MAPK1 (ERK2) activity, intervenes in cell proliferation and differentiation, promotes cell cycle arrest, and reduces tumor cell proliferation.

4. Regulates tumor microenvironment-related proteins
   Gardenia flavin B inhibits MMP9 expression, reduces the matrix degradation and invasion ability of tumor cells, and prevents tumor metastasis. Its regulation of EGFR and PIK3CA further influences tumor cell proliferation and survival.

5. Regulates telomerase activity
   By inhibiting TERT expression, gardenia flavin B may affect telomere maintenance in tumor cells, limiting their unlimited proliferative capacity.

6. USP7 and ODC suppression
   USP7, as a deubiquitinating enzyme, participates in the stabilization of various tumor-related proteins. Gardenia flavin B promotes the degradation of tumor suppressor proteins by inhibiting USP7, exerting anti-tumor effects. As a key enzyme in polyamine synthesis, ODC inhibition helps suppress tumor cell metabolic activity and proliferation.

In summary, Gardeniflavin B achieves effective inhibition of tumor cells through multi-target and multi-pathway synergistic effects, demonstrating its potential as a natural candidate molecule for anti-tumor drugs.

Druggability evaluation and pharmacokinetics

The druggability parameters of Gardenia Flavin B indicate that it has certain potential for drug development. Its molecular weight is moderate (358.3460), meeting the basic requirements of the Lipinski rule. The LogP value was 2.56, indicating moderate lipid solubility, which is beneficial for oral absorption and cell membrane penetration. Lower water solubility (0.0087) may limit its bioavailability, but it can be improved through pharmaceutical methods such as nanocarriers and solid dispersions.

The blood-brain barrier has low permeability, reducing the risk of central nervous system toxicity, making it suitable for treating non-central nervous system tumors. hERG suppression tests were negative, indicating a low risk of cardiotoxicity. Ames test results showed that it carries low genotoxicity risk and is relatively safe.

Currently, pharmacokinetic research on gardenia flavin B is relatively limited. Preliminary data indicate that its metabolism is stable in vivo, mainly transformed through hepatic metabolic enzyme systems, and its metabolites still require further identification. In the future, systematic pharmacokinetic and toxicological studies are needed to clarify its in vivo absorption, distribution, metabolism, and excretion (ADME) characteristics, providing a basis for clinical application.

Prospects and outlooks for clinical applications

Gardenia flavin B, with its remarkable antioxidant and antitumor activities, especially its potential application value in solid tumors such as liver cancer, has become a hotspot in the development of natural product drugs. Its multi-target mechanism gives it advantages in both monotherapy and combination chemotherapy, and is expected to overcome issues of tumor drug resistance and side effects.

Future research should focus on the following directions:

1. In-depth mechanism research
   Further elucidation of the signaling network of gardenia flavin B within tumor cells and the molecular mechanisms of its interaction with immune regulation and the tumor microenvironment are explored.

2. Pharmacokinetics and safety assessment
   Systematically conduct in vivo pharmacokinetics, toxicology, and long-term safety studies, clarifying the dosage range and safety window for clinical application.

3. Formulation development and route of administration optimization
   To address its poor water solubility, new drug delivery systems such as liposomes and nanoparticles have been developed to improve bioavailability and targeting.

4. Preclinical and clinical trials
   Combining animal models to verify its anti-tumor efficacy and safety, clinical trials are gradually advancing to evaluate its efficacy and safety in treating liver cancer and other tumors.

5. Combination medication strategies
   Explore combined applications with existing chemotherapy drugs, targeted drugs, and immunotherapy drugs to maximize synergistic effects and improve treatment outcomes.

In summary, as a multifunctional natural flavonoid compound, Gardenia flavonin B has broad clinical application prospects and is worthy of in-depth development and research.

Conclusion

Gardenia flavin B, a natural methoxyflavonoid derived from traditional Chinese medicine gardenia, demonstrates significant research value in antioxidant and antitumor fields due to its unique chemical structure and multi-target pharmacological activity. Its inhibitory effects on key enzymes such as USP7, ODC, and Cathepsin D, as well as regulation of liver cancer-related signaling pathways, reveal its complex and effective mechanisms of action. Although there are still some gaps in pharmacokinetics and clinical research, its solid druggability parameters and safety foundation provide a solid foundation for subsequent drug development. In the future, through multidisciplinary collaboration combined with modern drug development technologies, Gardenia Flavin B is expected to become an important candidate molecule for the development of natural anti-tumor drugs, offering new treatment options for cancer patients.