Product name: Amentoflavone
Synonym name:
Catalogue No.: BP0161
Cas No.: 1617-53-4
Formula: C₃₀H₁₈O₁₀
Mol Weight: 538.464
Botanical Source: Metasequoia glyptostroboides, Viburnum prunifolium, Podocarpus gracilior, Garcinia livingstonei, Selaginella willdenowii, Rhus succedanea, Garcinia multiflora, Ginkgo biloba, Cupressocyparis leylandii, Cryptomeria japonica, Amentotaxus formos
Physical Description: Yellow powder
Type of Compound: Flavonoids

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, up to kilograms
Inquire for bulk scale.

Descriptions:
Amentoflavone, a biflavonoid with antiinflammatory activity, inhibits NF-κB/DNA binding activity potently along with inhibition of degradation of IκBα and NF-κB translocation into nucleus in TNFα-activated A549 cells.[1]
Amentoflavone has the inhibition of LPS-induced NO formation, is due to its inhibition of NF-kappaB by blocking degradation, which may be the mechanistic basis of the anti-inflammatory effects of amentoflavone.[2]
Amentoflavone has been shown to inhibit tumor metastasis in vivo, amentoflavone treatment reduces experimental tumor metastasis and suggest that such an action is associated with attenuation of tumor invasion, proliferation and angiogenesis.[3]
Amentoflavone has been shown to inhibit tumor metastasis in vivo, inhibits experimental tumor metastasis through a regulatory mechanism involving MMP-2, MMP-9, prolyl hydroxylase, lysyl oxidase, VEGF, ERK-1, ERK-2, STAT-1, NM23 and cytokines in lung tissues of C57BL/6 mice.[4]
Amentoflavone and its derivatives as novel natural inhibitors of human Cathepsin B(CatB), CatB is a member of the papain superfamily of cysteine proteases and has been implicated in the pathology of numerous diseases, including arthritis and cancer. [5]
Amentoflavone induces breast cancer apoptosis through blockade of fatty acid synthesis.[6]
Amentoflavone exhibits potent antifungal activity against several pathogenic fungal strains but has a very low hemolytic effect on human erythrocytes, it induces the accumulation of intracellular trehalose on C. albicans as a stress response to the drug, and disrupts the dimorphic transition that forms pseudo-hyphae during pathogenesis, it has great potential to be a lead compound for the development of antifungal agents.[7]


References:
[1] Banerjee T, Valacchi G, Ziboh V A, et al. Mol Cell Biochem, 2002, 238(1-2):105-10.
[2] Woo E R, Lee J Y, Cho I J, et al. Pharmacol Res, 2005, 51(6):539-46.
[3] Guruvayoorappan C, Kuttan G. Biochemistry, 2008, 73(2):209-18.
[4] Guruvayoorappan C, Kuttan G. Immunopharm Immunot, 2008, 30(4):711-27.
[5] Pan X, Tan N, Zeng G, et al. Bioorg Med Chem, 2005, 13(20):5819-25.
[6] Lee J, Lee M, Oh W, et al. Biol Pharm Bull, 2009, 32(8):1427-32.
[7] Jung H J, Sung W S, Yeo S H, et al. Arch Pharm Res, 2006, 29(9):746-51.
[8] Sun D M, Luo W H, Zhi-Yong L I. Journal of Chinese medicinal materials, 2006, 29(29):26-8.

HPLC of Amentoflavone

HNMR of Amentoflavone

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

Introduction/Overview

Natural products, as an important source of drug discovery and development, play an irreplaceable role in the history of human disease prevention and treatment. Among them, flavonoids have attracted much attention due to their wide range of biological activities and low toxicity. Amentoflavone, as a unique flavonoid compound, is composed of two apigenin units connected by a C-3 '- C-8' 'diaryl ether bond. Since its discovery, its diverse and significant pharmacological activities have gradually become a hot topic in pharmacological research. This compound is widely present in Ginkgo biloba（Ginkgo biloba L.）、 Guanye Lianqiao（Hypericum perforatum L. ) and a variety of cypress and Arhat pine plants, which is one of the important material bases for these traditional medicinal plants to play their roles.

Modern pharmacological studies reveal that arachidonic biflavones exhibit remarkable characteristics of multi target and multi pathway actions, and their activities cover many fields such as anti-inflammatory, antioxidant, antiviral, anti-tumor, neuroprotective, anti diabetes and cardiovascular protection. More importantly, it has been identified as a new natural inhibitor of human cathepsin B (CatB) and plays a central role in regulating Wnt/β - catenin, NF - κ B, MAPK and other key signal pathways, which provides a solid scientific basis for its intervention in complex diseases such as tumors, neurodegenerative diseases, fibrosis diseases and infectious diseases. Despite challenges such as poor water solubility and low blood-brain barrier permeability, its high efficiency and low toxicity make it a highly promising lead compound for drug development. This article aims to provide a systematic review of the chemical properties, plant sources, pharmacological activities, mechanisms of action, and pharmacological research progress of Sophora japonica flavonoids, and to explore their clinical application prospects.

Chemical structure and physicochemical properties

Suihuashan flavonoids (CAS number: 1617-53-4), chemical name 8- [5- (5,7-dihydroxy-4-oxo-4H-chromene-2-yl) -2-hydroxyphenyl] -5,7-dihydroxy-2- (4-hydroxyphenyl) -4Hchromene-4-one, molecular formula C30H18O10, molecular weight 538.4640. Its core structure is formed by oxidative coupling of two apigenin monomers, with the specific connection method being the formation of a carbon carbon bond (C-3 '- C-8' 'diaryl bond) between the B ring C-3' position of one apigenin unit and the A ring C-8 position of another apigenin unit. This unique connection method forms the basis of its dual flavonoid skeleton and significantly affects its spatial conformation and biological activity.

From the analysis of physical and chemical properties, Suihuashan flavonoids belong to typical hydrophobic polyphenolic compounds. The calculated lipid water partition coefficient (LogP) is about 3.43, indicating that it has good lipid solubility. However, its topological polar surface area (TPSA) is as high as 181.80 Å ², and its water solubility is extremely low (about 0.0037 mg/mL), which poses the primary challenge for its formulation development. This compound contains multiple phenolic hydroxyl groups, giving it strong hydrogen bond donor/acceptor ability, which is also the structural basis for its strong antioxidant activity and easy binding to various enzyme/acceptor active sites. The preliminary risk assessment of its medicinal properties shows that its Ames test result is 0.6 (usually considered to have potential mutagenic risk if it is greater than 1.5), indicating a low risk of genetic toxicity; Meanwhile, it does not inhibit hERG potassium channels, indicating a lower risk of potential arrhythmogenic cardiac toxicity. However, it should be noted that its blood-brain barrier permeability is predicted to be "low", which may limit its direct efficacy in central nervous system diseases and needs to be improved through structural modifications or drug delivery systems.

Plant sources and extraction methods

Suihuashan flavonoids are relatively widely distributed in nature, mainly found in gymnosperms and some dicotyledonous plants.
1. Main plant sources：
* Ginkgo family Ginkgo biloba leaves are one of the most abundant and well-known sources of isoflavones in Chinese fir. The various pharmacological effects of Ginkgo biloba extract (EGb 761) are believed to be related to the flavonoid components it contains, including genistein.
* Fujicaceae/Primulaceae Forsythia suspensa (St. John's wort) is another important source, partially attributed to its antidepressant and antiviral activity.
* Other sources: This compound is also found in Podocarpus mongolicus, Walmaishan, Selaginella Selaginella (Revival Grass) and some ferns, and is one of the characteristic components of the secondary metabolites of these plants.
2. Extraction and Separation Methods Due to the moderate to high polarity and relative stability to heat and light of the flavonoids in Taxodium sibiricum, organic solvent extraction is commonly used for their extraction.
* Conventional extraction Methanol, ethanol, acetone, or their aqueous solutions are commonly used for reflux extraction or ultrasound assisted extraction of dried plant materials.
* Purification and Separation: After the crude extract is extracted by solvent such as petroleum ether and ethyl acetate, the ethyl acetate part rich in arachis biflavone can be separated and purified by a variety of chromatographic technologies, such as silica gel column chromatography, polyamide column chromatography, Sephadex LH-20 column chromatography, high-performance liquid chromatography (HPLC), high-speed countercurrent chromatography (HSCCC) and other modern preparation chromatographic technologies. Its identification mainly relies on spectroscopic methods such as ultraviolet spectroscopy (UV), mass spectrometry (MS), and nuclear magnetic resonance spectroscopy (NMR).

Pharmacological activity research

A large number of in vitro and in vivo studies have confirmed that the dual flavonoids of Taxodium sibiricum have broad and powerful pharmacological activities, demonstrating their potential for application in multiple disease fields.

1. Anti inflammatory and antioxidant activity Suihuashan flavonoids are effective antioxidants that can directly eliminate free radicals and upregulate the activity of intracellular antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GPx). Its anti-inflammatory effect is particularly prominent, which can significantly inhibit the production of nitric oxide (NO), prostaglandin E2 (PGE2), and pro-inflammatory cytokines (such as TNF - α, IL-1 β, IL-6) in macrophages induced by stimuli such as lipopolysaccharide (LPS). These effects are important foundations for its neuroprotection, cardiovascular protection, and anti-tumor activity.
2. Antiviral activity Research has shown that genistein from Taxodium distemper has inhibitory effects on various viruses, including human immunodeficiency virus (HIV), hepatitis C virus (HCV), dengue virus, herpes simplex virus (HSV), and SARS coronavirus. Its mechanism of action is diverse, involving inhibition of virus entry into cells, interference with key viral replication enzymes (such as HCV NS5B RNA polymerase), and regulation of host immune response.
3. Antitumor activity Adzuki biflavone showed growth inhibition and apoptosis promoting effects on a variety of cancer cell lines (such as lung cancer, breast cancer, liver cancer, colon cancer, glioma, etc.). It can induce cancer cell cycle arrest (commonly in G1 phase or sub-G1 phase) and activate the Caspase cascade through the mitochondrial pathway and death receptor pathway, leading to cell apoptosis. In addition, it can inhibit the migration, invasion, and angiogenesis of tumor cells, demonstrating anti metastatic potential.
4. Neuroprotective activity In Alzheimer's disease (AD), Parkinson's disease (PD), and cerebral ischemic injury models, Sophora flavescens has shown protective effects. It can inhibit the neurotoxicity induced by β - amyloid protein (A β), reduce tau protein hyperphosphorylation, inhibit β - secretase 1 (BACE1) activity, and thus reduce A β production. Its anti-inflammatory and antioxidant properties also help alleviate neuroinflammation and oxidative stress damage.
5. Anti diabetes and cardiovascular protective activity Anthurium fortunei biflavone can improve insulin resistance and inhibit the activity of aldose reductase (AKR1B1), thus reducing the complications of diabetes. In cardiovascular aspect, it can improve lipid metabolism by activating AMPK signaling pathway, inhibit the proliferation of vascular smooth muscle cells, and inhibit endothelial cell mediated angiogenesis by inhibiting cathepsin B (CatB) and NF - κ B pathways, which is of great significance in preventing atherosclerosis and pathological vascular hyperplasia (such as hypertrophic scar).
6. Antibacterial and antifungal activity Has a certain inhibitory effect on certain Gram positive bacteria and fungi, such as Candida albicans.
7. Other activities The study also reported its activities such as anti radiation, anti anxiety (as a negative regulator of GABA (A) receptors), and regulation of estrogen receptor 2 (ESR2).

Mechanism of action and molecular targets

The multiple pharmacological activities of Sophora japonica flavonoids stem from their interactions with multiple key target proteins and signaling pathways within cells, reflecting the characteristics of multi-target therapy.

1. Core enzymes and protein targets：
   • Cathepsin B (CatB)Identified as a novel, natural human CatB inhibitor. CatB is a lysosomal cysteine protease that plays a critical role in tumor invasion, angiogenesis, and cell apoptosis. Inhibition of CatB is an important mechanism for the anti-tumor and anti angiogenic effects of Sophora japonica flavonoids.
   • β - secretase 1 (BACE1)Directly inhibiting BACE1 activity and reducing A β production is one of its core mechanisms for anti AD effects.
   • Protein tyrosine phosphatase 1B (PTPN1)Inhibition of PTPN1 can enhance insulin receptor signal transduction and improve insulin sensitivity, which is related to its anti diabetes activity.
   • Aldehyde reductase (AKR1B1): Effectively inhibit AKR1B1, block polyol pathway, and reduce complications of diabetes.
   • Cytochrome P450 enzymes (CYPs)As a P450 inhibitor, it may affect the metabolism of other drugs, indicating potential drug drug interactions.
2. Regulation of key signaling pathways：
   • NF - κ B signaling pathway Suihuashan flavonoids can effectively inhibit the phosphorylation and degradation of I κ B α, prevent the nuclear translocation of NF - κ B p65 subunit, and thereby downregulate the expression of various downstream pro-inflammatory factors, anti apoptotic proteins (such as Bcl-2), and angiogenic factors. This is the core pathway for its anti-inflammatory, anti-tumor, and apoptosis inducing properties.
   • Wnt/β - catenin signaling pathway In various cancer cell and fibrosis models, it can downregulate the protein expression and nuclear localization of β - catenin, inhibit the transcription of downstream target genes such as c-Myc and Cyclin D1, thereby suppressing cell proliferation and epithelial mesenchymal transition (EMT).
   • MAPK signaling pathway It can regulate the phosphorylation levels of ERK, JNK, and p38 MAPK, and its specific effects are cell type and stimulus dependent, participating in the regulation of cell proliferation, differentiation, and apoptosis.
   • PI3K/Akt signaling pathway Inhibiting the phosphorylation activation of Akt, which in turn affects multiple downstream targets such as mTOR and GSK-3 β, is associated with inducing apoptosis and inhibiting growth.
   • AMPK signaling pathway Activation of AMPK promotes fatty acid oxidation, inhibits cholesterol synthesis, and regulates autophagy, contributing to its cardiovascular protective and metabolic regulatory effects.
3. Regulation of apoptosis related proteins Upregulation of pro apoptotic protein Bax and downregulation of anti apoptotic protein Bcl-2 lead to loss of mitochondrial membrane potential, release of cytochrome C, and ultimately activation of Caspase-3, executing the cell apoptosis program.

Evaluation of drug properties and pharmacokinetics

Although the pharmacological activity of Sophora japonica flavonoids is excellent, there are significant shortcomings in their drug like properties, which are obstacles that must be overcome during their conversion into drugs.

1. Absorption, distribution, metabolism, excretion (ADME) characteristics：
   • absorb Due to its low water solubility and high molecular weight, oral bioavailability is expected to be low. Animal studies have shown that its oral absorption rate is slow, and its absolute bioavailability needs to be improved.
   • distribution Has a high plasma protein binding rate. As mentioned earlier, its blood-brain barrier permeability is poor, which limits drug exposure to the central nervous system.
   • Metabolism As a substrate and inhibitor of P450 enzymes, it is mainly metabolized in the liver through phase II metabolic reactions such as glucuronidation and sulfation. It may also interact with other drugs metabolized by CYP.
   • excretion Metabolites are mainly excreted through bile and urine.
2. Challenges and optimization strategies for drug development：
   • Water solubility and bioavailability Low water solubility is the biggest challenge. The current research strategies include:
     • Structural modification Methylation, glycosylation, or preparation of prodrugs (such as phosphate esters and amino acid esters) of its phenolic hydroxyl groups to improve solubility and stability.
     • Formulation technology Using nanotechnology, such as preparing nanocrystals, liposomes, polymer nanoparticles, solid dispersions, or cyclodextrin inclusion complexes, can significantly improve their dissolution rate and oral bioavailability.
   • Blood-brain barrier delivery To treat central nervous system diseases, it is necessary to develop delivery systems that can promote BBB penetration, such as nanoparticles modified with targeted peptides or alternative routes of nasal administration.
   • Targeted delivery Developing nano formulations with active targeting (such as folate, RGD peptide modification) or passive targeting (EPR effect) for specific tissues such as tumors can improve therapeutic efficacy and reduce systemic toxicity.
3. safety Existing in vitro and partial in vivo studies have shown that its toxicity is relatively low. A negative Ames test and no hERG inhibition are positive signals for its safety. However, comprehensive preclinical toxicology studies (such as long-term toxicity and reproductive toxicity) still need to be systematically conducted.

Clinical application prospects and prospects

As a multi-target natural lead compound, the dual flavonoids of Taxodium sibiricum have broad development prospects in various disease fields.

1. Potential therapeutic areas：
   • tumor therapy Especially suitable for tumor types that are resistant to traditional chemotherapy or require multi-path inhibition, such as glioblastoma, liver cancer, etc. Combining with existing chemotherapy drugs may result in synergistic effects, reducing dosage and toxicity.
   • Neurodegenerative diseases As a disease modifier for AD and PD, its multi-target properties (inhibition of A β production, anti tau lesions, anti neuroinflammation) have unique advantages. Need to address BBB delivery issues.
   • Metabolic and cardiovascular diseases It has potential in the prevention and treatment of diabetes and its complications (such as nephropathy, retinopathy), non-alcoholic fatty liver disease (NAFLD) and atherosclerosis.
   • Fibrotic disease Based on its inhibitory effects on CatB, regulation of β - catenin, and inhibition of angiogenesis, it has promising prospects in the treatment of hypertrophic scars, liver fibrosis, pulmonary fibrosis, and other conditions.
   • antiviral therapy Can be used as a candidate molecule for broad-spectrum antiviral drugs, especially for newly emerging viral infectious diseases.
2. Future research directions：
   • In depth mechanism exploration Using chemical biology methods (such as chemical proteomics) to systematically discover new direct targets and draw a more complete pharmacological action network.
   • Structural optimization and structure-activity relationship Systematically studying the effects of structural modifications (such as selective protection or introduction of specific functional groups) on activity, selectivity, and drug formation, with the aim of obtaining better candidate drugs.
   • Advanced delivery system development Vigorously invest in research on intelligent delivery systems based on nanotechnology to address core challenges such as solubility, targeting, and BBB penetration.
   • Preclinical and clinical translation Conduct Good Laboratory Practice (GLP) toxicology and pharmacokinetic studies that comply with regulations, and provide data support for its clinical trial application (IND). Explore its value in combination therapy.

Conclusion

As a plant derived natural product of flavonoids, Suihuashan flavonoids exhibit excellent biological activity in anti-inflammatory, antioxidant, anti-tumor, neuroprotective, metabolic regulation, and other aspects due to their unique chemical structure and multi-target, multi pathway pharmacological mechanisms. It is not only a key component for explaining the pharmacological substance basis of traditional medicinal herbs such as Ginkgo biloba and Forsythia suspensa, but also a modern drug lead compound with great development value. Despite facing challenges such as poor water solubility and low bioavailability, with the rapid development of modern medicinal chemistry, pharmacy, and nanotechnology, these obstacles are expected to be overcome one by one through rational structural modification and innovative formulation strategies. In the future, in-depth research on the dual flavonoids of Taxodium sibiricum will undoubtedly promote its steady progress from laboratory to clinical translation, providing new weapons and hope for humanity to address major health challenges such as tumors, neurodegenerative diseases, and metabolic syndrome.