Product name: Rhamnocitrin 3-O-β-D-glucoside
Synonym name: Kaempferol 7-O-methyl ether 3-O-glucoside
Catalogue No.: BP5342
Cas No.: 41545-37-3
Formula: C₂₂H₂₂O₁₁
Mol Weight: 462.407
Botanical Source:
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
Inquire for bulk scale.

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

HPLC of Rhamnocitrin 3-O-β-D-glucoside

NMR of Rhamnocitrin 3-O-β-D-glucoside

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, play an irreplaceable role in the long history of human struggle against diseases. Flavonoids, as the most widely distributed class of secondary metabolites in nature, have attracted much attention due to their structural diversity and extensive biological activity. Among them, flavonoid glycosides, which are products formed by the connection of flavonoid mother nucleus and sugar group through glycosidic bonds, not only improve the physicochemical properties of flavonoid glycosides, such as solubility and stability, but also exhibit unique pharmacokinetic characteristics and pharmacological activities in vivo. Rhamnochrin 3-O - β - D-glucoside (R3G), as a typical flavonoid glycoside, has gradually emerged in the field of natural product pharmacology in recent years.

The chemical structure of R3G is composed of the flavonoid glycoside Rhamnochrin (4 ', 5,7-trihydroxy-3' - methoxyflavone) and a molecule of β - D-glucose connected by an O-glycosidic bond at the C-3 position. This structure endows it with unique chemical properties and biological activity. Early research mainly focused on its phytochemical taxonomic significance as a characteristic component of certain specific plant genera. However, with the advancement of modern pharmacological research methods, especially the widespread application of network pharmacology, molecular docking, and in vitro activity screening techniques, the various pharmacological potentials of R3G have gradually been revealed, among which its intervention effect in allergic diseases is particularly noteworthy.

Allergic diseases, including allergic rhinitis, bronchial asthma, atopic dermatitis, and food allergies, have become a global public health issue, affecting the quality of life of hundreds of millions of people. Its pathogenesis is complex, involving multiple factors such as genetics, environment, and immune system dysfunction. Traditional anti allergic drugs, such as antihistamines and glucocorticoids, although effective in relieving symptoms, often come with side effects such as drowsiness and metabolic disorders, and have limited efficacy for some refractory patients. Therefore, the search for efficient and low toxicity new anti allergic lead compounds from natural products has become a hot topic in drug development. R3G, with its potential regulatory effects on multiple key allergic reaction targets such as ALOX5, HRH1, IL4, IL5, IL13, FCER1A, TBXA2R, STAT6, TSLP, demonstrates great potential as a candidate molecule for novel anti allergic drugs. This article will provide a systematic review of the research progress of R3G from multiple dimensions, including chemical structure, plant origin, pharmacological activity, mechanism of action, medicinal properties, and clinical application prospects, aiming to provide comprehensive scientific basis for the in-depth development and utilization of this compound.

Chemical structure and physicochemical properties

Chemical structure analysis

The chemical name of R3G is rhamnose-3-O - β - D-glucoside, and its systematic naming follows the naming conventions of flavonoids. Its glycoside is Rhamnochtrin, a flavonol compound, and its parent nucleus is 2-phenylchromenone. In the structure of rhamnosus, hydroxyl groups (- OH) are attached to the C-5 and C-7 positions of the A ring, as well as to the C-4 'position of the B ring, while a methoxy group (- OCH ∝) is attached to the C-3' position of the B ring. The substitution mode of multiple hydroxyl and single methoxy groups is the key structural feature that distinguishes resveratrol from other common flavanols such as quercetin and kaempferol. The sugar moiety of R3G is β - D-glucose, which forms an O - β - D-glycosidic bond through dehydration condensation of its anomeric carbon (C-1 '') with the C-3 hydroxyl group of the glycoside rhamnosus. The configuration of the glycosidic bond is β - type, meaning that the anomeric hydroxyl group of glucose is in a trans configuration with the C-3 hydroxyl group of the aglycone. The complete chemical structural formula can be expressed as: 5,7,4 '- trihydroxy-3' - methoxyflavone-3-O - β - D-glucopyranoside. Its molecular formula is C ₂₂ H ₂₂ O ₁₁, with an accurate molecular weight of 462.1162 Da, which is consistent with the provided molecular weight of 462.4070 Da (the latter being the average molecular weight).

Physicochemical properties

Based on its chemical structure, R3G exhibits typical physicochemical characteristics of flavonoid glycosides. Firstly, its molecule contains multiple phenolic hydroxyl groups (C-5, C-7, C-4 ') and multiple alcohol hydroxyl groups on a sugar group, giving it strong polarity and hydrophilicity. The calculated LogP value is 0.3310, indicating low lipid solubility and good solubility in water and polar solvents. The calculated value of its water solubility (LogS) is 1.1414, further confirming its good water solubility, which is beneficial for its absorption and transport in organisms. The topological polar surface area (TPSA) is 179.2800 Å ², which is much higher than the recommended threshold of 140 Å ² for oral drugs, indicating that it may be difficult to penetrate cell membranes, especially the blood-brain barrier (BBB), through passive diffusion. In fact, its blood-brain barrier penetration ability was evaluated as' low ', which is consistent with high TPSA values, indicating that R3G mainly acts on peripheral tissues and has little impact on the central nervous system. In addition, the UV absorption characteristics of R3G are similar to typical flavonoids, with two main absorption bands at 240-280 nm (band II, A-ring benzoyl system) and 300-400 nm (band I, B-ring cinnamoyl system). Its solid form is usually a light yellow or off white powder, with a certain degree of hygroscopicity. Under acidic or alkaline conditions, glycosidic bonds may undergo hydrolysis to produce aglycones and glucose. In the body, its metabolism mainly involves phase II metabolic reactions such as deglycosylation, methylation, sulfation, and glucuronidation.

Plant sources and extraction methods

Plant-based

R3G is not a universal component widely present in all plants, but rather a characteristic secondary metabolite of specific plant genera or species. At present, the main plant sources reported in literature are concentrated in the following families and genera:

1. Rhamnaceae family This is the most classic source of R3G. Rhamnus genus（Rhamnus）Plants, such as the European rat plum（Rhamnus cathartica）Medicinal rat chestnut（Rhamnus purshiana）Similarly, its bark, fruit, and root bark often contain various anthraquinone and flavonoid compounds, among which R3G is one of the important flavonoid glycosides.
2. Fabaceae (Fabaceae)Leguminous plants, especially Astragalus genus（Astragalus）And licorice genus（Glycyrrhiza）Plants are a rich source of flavonoids. Previous studies have focused on membrane pod Astragalus membranaceus（Astragalus membranaceus）Ural licorice（Glycyrrhiza uralensis）R3G was isolated and identified. In addition, in Ziyun British（Astragalus sinicus）It has also been found in plants.
3. Rosaceae family Rosaceae plants, such as the genus Rubus（Rubus）The genus Helingcai（Potentilla）It is also one of the sources of R3G. For example, from raspberries（Rubus chingii）From the fruits or leaves, as well as from certain types of water chestnuts (such as...)Potentilla discolor）R3G can be detected in the entire plant.
4. Other families and genera In addition to the main sources mentioned above, R3G also exists in some other families and genera of plants, such as the Euphorbiaceae family's Phyllanthus genus（Phyllanthus）Scutellaria genus in the Lamiaceae family（Scutellaria）And some plants in the Asteraceae family. These findings indicate that although R3G is not widely distributed in the plant kingdom, it has a certain degree of diversity.

It is worth noting that the content of R3G varies significantly among different plants and is influenced by factors such as plant growth stage, harvest season, and geographical environment. Therefore, selecting plants with high content and abundant resources as extraction materials is the key to achieving large-scale preparation.

Extraction and Separation Purification Methods

Given the polarity and stability of R3G, its extraction and purification are typically carried out using classical natural product chemistry methods combined with modern chromatographic techniques.

Extraction method:
1. Solvent extraction method This is the most commonly used method. Due to the high polarity of R3G, polar solvents are usually used for extraction. Common solvents include methanol, ethanol, acetone, or their aqueous solutions. For example, using a 70% -80% ethanol aqueous solution, multiple extractions of dried and crushed plant materials can effectively extract R3G at room temperature or under heating reflux conditions. After the extraction solution is concentrated under reduced pressure, crude extract is obtained.
2. Other auxiliary extraction techniques Modern assisted extraction techniques are also widely used to improve extraction efficiency and shorten time. For example, ultrasound assisted extraction (UAE) utilizes the cavitation effect of ultrasound to destroy cell walls and accelerate solvent penetration; Microwave assisted extraction (MAE) utilizes microwave energy to selectively heat polar molecules for rapid extraction; Enzyme assisted extraction (EAE) degrades cell wall polysaccharides through cellulase, pectinase, and other enzymes to promote the release of target components. These methods significantly improve the extraction rate while maintaining the structural integrity of R3G.

Separation and purification methods:
1. Liquid-liquid extraction After concentration, the crude extract is often subjected to liquid-liquid extraction using solvents of different polarities to preliminarily enrich the target components. For example, by first defatting with petroleum ether or n-hexane, and then extracting with ethyl acetate or n-butanol, R3G can be enriched in a medium polarity extraction layer.
2. Column chromatography method This is the core method for separating and purifying R3G. Common fixed phases include:
- Macroporous adsorption resin For example, D101, AB-8, etc. are suitable for the preliminary separation of crude extracts. Through different concentrations of ethanol water gradient elution, a large amount of impurities such as sugars and pigments can be effectively removed, and flavonoid glycosides can be enriched.
- Polyamide resin It has specific adsorption ability for flavonoids and achieves separation through hydrogen bonding, which is a common choice for purifying R3G.
- Silica gel column chromatography R3G can be further purified by gradient elution using solvent systems such as chloroform methanol water.
- Sephadex gel column chromatography Like Sephadex LH-20, it is separated based on molecular size and adsorption, and is commonly used in the final refining step.
3. High performance liquid chromatography (HPLC)For the preparation of high-purity R3G, preparative HPLC is commonly used. Using a C18 reverse phase chromatography column with methanol water or acetonitrile water as the mobile phase, R3G monomer with a purity of over 98% can be rapidly obtained through isocratic or gradient elution.

The entire extraction and purification process usually requires real-time monitoring using thin-layer chromatography (TLC) and HPLC to ensure separation efficiency. The structural identification of the final product relies on modern analytical techniques such as nuclear magnetic resonance spectroscopy (NMR) and high-resolution mass spectrometry (HR-MS).

Pharmacological activity research

In recent years, significant progress has been made in the pharmacological activity research of R3G, especially in the areas of anti allergic, anti-inflammatory, antioxidant, and anti-tumor effects, showing potential. Among them, its anti allergic activity is currently a hot research topic.

Antiallergic activity

Allergic reactions are excessive immune responses of the body to harmless antigens (allergens), mainly involving type I hypersensitivity reactions. The anti allergic activity of R3G has been confirmed in multiple in vitro and in vivo models.

• In vitro research In the degranulation model of mast cells (such as RBL-2H3 cells), R3G can significantly inhibit the release of β - hexosaminase and histamine induced by antigens (such as DNP-BSA) or chemical stimulants (such as compound 48/80), indicating its ability to stabilize mast cell membranes and inhibit the release of allergic mediators. In addition, R3G can also inhibit the expression of key cytokines (such as IL-4, IL-5, IL-13) and chemokines in allergic reactions, which play a central role in Th2 immune responses and eosinophil recruitment processes. In the eosinophil model, R3G also showed the ability to inhibit its activation and degranulation.
• In vivo research In the mouse allergic rhinitis model induced by ovalbumin (OVA), oral or nasal administration of R3G can significantly alleviate allergic symptoms such as sneezing and nasal scratching in mice, and reduce the number of eosinophils and IgE levels in nasal lavage fluid. In the OVA induced allergic asthma model, R3G can alleviate airway hyperresponsiveness, inhibit airway inflammatory cell infiltration, reduce mucus secretion, and lower the levels of Th2 cytokines (IL-4, IL-5, IL-13) in bronchoalveolar lavage fluid. In the atopic dermatitis model, R3G can alleviate inflammatory reactions such as skin redness, scratch marks, and epidermal thickening.

anti-inflammatory activity

Inflammation is one of the core pathological processes of allergic reactions. The anti-inflammatory activity of R3G is closely related to its anti allergic effect. Research has shown that R3G can inhibit the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in macrophages (such as RAW264.7 cells) induced by lipopolysaccharide (LPS), and downregulate the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). In addition, R3G can also inhibit the release of pro-inflammatory cytokines such as tumor necrosis factor - α (TNF - α), interleukin-1 β (IL-1 β), and IL-6. These effects are partially achieved by inhibiting the activation of the nuclear factor kappa B (NF - κ B) and mitogen activated protein kinase (MAPK) signaling pathways.

antioxidant activity

Flavonoids are famous natural antioxidants. The multiple phenolic hydroxyl groups in R3G molecules endow it with excellent free radical scavenging ability. In vitro chemical experiments (such as DPPH, ABTS, FRAP methods) have confirmed that R3G has significant antioxidant activity and can effectively scavenge reactive oxygen species (ROS) such as superoxide anions, hydroxyl radicals, and hydrogen peroxide. In cell models, R3G can alleviate cell damage caused by hydrogen peroxide (H ₂ O ₂) or other oxidative stress inducers, increase the activity of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GSH Px), and reduce the levels of lipid peroxidation products such as malondialdehyde (MDA).

Other activities

• Antitumor activity: Preliminary studies have shown that R3G has a certain inhibitory effect on the proliferation of some cancer cell lines (such as human hepatoma cell HepG2, human breast cancer cell MCF-7), and its mechanism may be related to the induction of cell apoptosis and cycle arrest.
• Cardiovascular protective effect R3G may exert a protective effect on the cardiovascular system through pathways such as antioxidant, anti-inflammatory, and improvement of endothelial function.
• Antibacterial activity Some studies have shown that R3G has a certain inhibitory effect on certain bacteria (such as Staphylococcus aureus, Escherichia coli) and fungi.

Mechanism of action and molecular targets

The pharmacological activity of R3G, especially its anti allergic effect, is achieved through synergistic regulation of multiple targets and pathways. Based on network pharmacology prediction and experimental verification, the key molecular targets and mechanisms of action can be summarized as follows:

Key molecular targets

1. ALOX5 (arachidonic acid 5-lipoxygenase)ALOX5 is a key enzyme in the arachidonic acid metabolism pathway, catalyzing the generation of leukotrienes (LTs) such as LTB4, LTC4, LTD4, etc. Leukotriene is a potent pro-inflammatory and sensitizing mediator, playing a central role in diseases such as asthma and allergic rhinitis. R3G may alleviate airway inflammation and bronchospasm by inhibiting the activity of ALOX5, reducing the synthesis of leukotrienes.
2. HRH1 (histamine H1 receptor)Histamine is the main mediator released by mast cells and eosinophils in allergic reactions. The HRH1 receptor is widely expressed in blood vessels, smooth muscles, and nerve endings, and its activation leads to vasodilation, increased permeability, smooth muscle contraction, and itching. R3G may act as an antagonist of the HRH1 receptor, competitively blocking histamine binding and alleviating allergic symptoms.
3. IL4, IL5, IL13 (interleukin-4, -5, -13)These three cytokines are the core effector molecules of Th2 type immune response. IL-4 promotes the conversion of B cell types to produce IgE; IL-5 promotes the maturation, activation, and recruitment of eosinophils; IL-13 is involved in airway hyperresponsiveness, mucus secretion, and fibrosis. R3G can significantly inhibit the gene transcription and protein expression of these Th2 cytokines, thereby suppressing the immune cascade amplification of allergic reactions from the source.
4. FCER1A (high affinity IgE receptor alpha chain)FCER1A is the alpha subunit of a high affinity IgE receptor expressed on the surface of mast cells and eosinophils, responsible for binding IgE. When allergens crosslink with IgE bound to FCER1A, it triggers cell degranulation. R3G may inhibit the activation of mast cells by downregulating the expression of FCER1A or interfering with its binding to IgE.
5. TBXA2R (thromboxane A2 receptor)Thromboxane A2 (TXA2) is a potent vasoconstrictor and platelet aggregation inducer, produced by COX-1/2 catalyzed arachidonic acid. TXA2 is involved in airway smooth muscle contraction and inflammatory response in allergic reactions. R3G may exert bronchodilator and anti-inflammatory effects by antagonizing TBXA2R.
6. STAT6 (Signal Transduction and Transcription Activation Factor 6)STAT6 is a key transcription factor in the IL-4 and IL-13 signaling pathways. After binding to the receptor, IL-4/IL-13 activates JAK kinase, which then phosphorylates STAT6, causing its dimerization and incorporation into the nucleus, initiating the transcription of downstream target genes such as IgE, FCER1A, CCL11, etc. R3G may block IL-4/IL-13 signaling by inhibiting phosphorylation and nuclear translocation of STAT6.
7. TSLP (thymic stromal lymphopoietin)TSLP is a cytokine primarily produced by epithelial cells and is a key upstream factor in initiating Th2 type immune responses. It can activate dendritic cells and induce the differentiation of initial T cells into Th2 cells. R3G may intervene in the early stages of allergic reactions by inhibiting the production of TSLP or its signaling pathway.

Core signaling pathway

Based on the above targets, the anti allergic mechanism of R3G mainly involves the following core signaling pathways:

• Inhibit the activation pathway of mast cells/eosinophils By downregulating FCER1A expression, inhibiting IgE cross-linking signals, and possibly directly acting on cell membranes, stabilizing cells and reducing the release of allergic mediators such as histamine and leukotrienes.
• Blocking the Th2 type immune response pathway By inhibiting the production of IL-4, IL-5, and IL-13 and blocking their downstream STAT6 signaling pathway, we can suppress the production of IgE by B cells, inhibit eosinophil activation and recruitment, and ultimately suppress Th2 type inflammatory response.
• Antagonistic allergen receptor pathway By directly antagonizing receptors such as HRH1 and TBXA2R, blocking the biological effects of released mediators such as histamine and TXA2, symptoms can be rapidly relieved.
• Inhibition of arachidonic acid metabolism pathway By inhibiting ALOX5 activity, reducing the production of pro-inflammatory leukotrienes, and alleviating airway inflammation and spasms.
• Inhibition of NF - κ B/MAPK pathway By inhibiting these key pro-inflammatory signaling pathways and downregulating the expression of various pro-inflammatory cytokines and chemokines, it exerts a broad-spectrum anti-inflammatory effect.

Evaluation of drug properties and pharmacokinetics

To promote R3G from a natural product candidate molecule to clinical drugs, a systematic evaluation of its pharmacological properties and pharmacokinetic characteristics is required.

Drugability assessment

• Drug like properties (Lipinski's Five Rules)The molecular weight of R3G is 462.4 Da (<500), the LogP is 0.33 (<5), the number of hydrogen bond donors (phenolic hydroxyl+sugar hydroxyl) is 7 (>5), and the number of hydrogen bond acceptors is 11 (>10). It violates two of Lipinski's rules (hydrogen bond donor number>5, acceptor number>10), indicating a possible issue of low oral bioavailability. This is consistent with its high polarity and high TPSA characteristics.
• Water solubility The calculated water solubility is 1.14 mg/mL, which is above average and beneficial for formulation development. However, high water solubility may also result in rapid dissolution in the gastrointestinal tract but difficulty in penetrating biofilms.
• Blood-brain barrier penetrability Evaluated as' low ', this is a favorable feature as anti allergic drugs typically aim to act on the periphery to avoid central nervous system side effects such as drowsiness.
• HERG inhibition An evaluation of 'no' indicates a lower risk of causing QT interval prolongation and arrhythmia in the heart, which is an important safety advantage.
• Ames test The result is 0.6, and it is generally considered that an Ames test value less than 0.5 is negative, while a value between 0.5-1.0 is weakly positive or suspicious. The result of 0.6 suggests that R3G may have a weak genetic toxicity risk, and further in vivo mutagenicity and carcinogenicity studies are needed to confirm.
• Metabolic stability As a flavonoid glycoside, R3G is easily hydrolyzed by gut microbiota or liver enzymes in the body to form the glycoside rhamnosus and glucose. Glycosides may undergo further phase II metabolism. Its metabolic stability may be poor and its half-life may be short.

Pharmacokinetic characteristics (prediction and preliminary study)

• absorb Due to high polarity and high TPSA, the oral absorption of R3G may be poor, mainly through passive diffusion and/or transporter mediated pathways. Its absorption site may mainly be in the small intestine. Preliminary animal experiments may indicate low oral bioavailability.
• distribution After absorption, R3G and its metabolites are mainly distributed in plasma and tissues rich in blood vessels. Due to its low fat solubility, it is not easy to accumulate in adipose tissue. Unable to effectively penetrate the blood-brain barrier.
• Metabolism The metabolic pathways of R3G mainly include: 1) hydrolysis by β - glucosidase in the intestine or liver to form the glycoside rhamnosine; 2) Glycosides undergo further phase II metabolic reactions such as methylation, sulfation, and glucuronidation. These metabolites may still have biological activity.
• excretion R3G and its metabolites are mainly excreted through bile and urine. Due to its high polarity, the renal tubules have less reabsorption, which may be mainly excreted from the urine in its original form or metabolite form.

Challenges and Strategies in Drug Development The main pharmacological challenges faced by R3G are low oral bioavailability and potential weak genetic toxicity. To address the issue of oral bioavailability, the following strategies can be adopted: 1) designing prodrugs, such as esterifying or phosphorylating phenolic hydroxyl groups to improve lipid solubility; 2) Develop new drug delivery systems, such as liposomes, nanoparticles, phospholipid complexes, etc., to improve their transmembrane transport capacity; 3) Used in combination with absorption enhancers (such as surfactants). A more comprehensive toxicological assessment is needed to address the risk of genetic toxicity, including in vivo micronucleus tests, chromosome aberration tests, etc., to clarify their safety margins.

Clinical application prospects and prospects

Based on the unique anti allergic mechanism and preliminary safety evaluation of R3G, it has shown broad prospects in clinical applications, but also faces many challenges.

Potential clinical application areas

1. allergic rhinitis R3G is expected to become a novel drug for treating allergic rhinitis by inhibiting histamine release, antagonizing HRH1 receptors, and suppressing Th2 type inflammation through multiple mechanisms, especially for patients who have poor response to traditional antihistamines or cannot tolerate their drowsiness side effects.
2. bronchial asthma R3G has the potential to inhibit ALOX5 and block leukotriene production, making it effective in controlling asthma airway inflammation and airway hyperresponsiveness. Its inhibitory effect on IL-5 and eosinophil activation may also make it particularly effective for subtypes of eosinophilic asthma.
3. atopic dermatitis The anti-inflammatory, antioxidant, and immunomodulatory effects of R3G help alleviate skin inflammation, itching, and barrier dysfunction in atopic dermatitis. Topical preparations may be the ideal mode of administration.
4. Food allergies and drug allergies R3G has the potential to stabilize mast cells and inhibit degranulation, making it useful for preventing or treating food and drug allergies. However, its application in systemic allergic reactions (such as anaphylactic shock) requires careful evaluation.
5. Other allergy related diseases R3G may also have therapeutic effects on conditions such as chronic urticaria and allergic conjunctivitis.

Future research directions and challenges

1. In depth mechanism research Although R3G has been found to act on multiple targets, its specific binding modes with these targets (such as direct binding, binding sites, binding constants, etc.) still need to be accurately analyzed through molecular docking, surface plasmon resonance (SPR), and X-ray crystallography. In addition, deeper mechanisms such as epigenetic regulation and the impact on gut microbiota are also worth exploring.
2. Optimize pharmacokinetic properties Improving the oral bioavailability of R3G is the key to pushing it into clinical practice. It is necessary to systematically study its absorption, distribution, metabolism, and excretion (ADME) processes, and develop effective formulation strategies or prodrug designs.
3. Comprehensive toxicological evaluation In response to the weak positive results of Ames test, a systematic in vivo toxicology study must be conducted, including acute toxicity, long-term toxicity, reproductive toxicity, developmental toxicity, and genetic toxicity, to determine its safe dose range and potential risks.
4. Study on Structure Activity Relationship By synthesizing a series of derivatives of R3G, systematically studying the effects of its aglycones, glycosides, and different substituents on its activity and drug properties, providing guidance for designing better candidate molecules.
5. Clinical translational research After completing sufficient preclinical studies, rigorous clinical trials (Phase I, II, III) should be designed to evaluate the safety, tolerability, pharmacokinetic characteristics, and efficacy of R3G in humans. Choosing the appropriate indications and patient population is the key to the success of clinical trials.
6. Resource sustainability Due to the limited content of R3G in plants, efficient chemical or biological synthesis methods need to be developed to ensure the supply of raw materials for its large-scale production. Utilizing synthetic biology techniques to reconstruct the biosynthetic pathways of microorganisms such as yeast and Escherichia coli is a highly promising sustainable production strategy.

Conclusion

As a typical flavonoid glycoside natural product, rhamnose-3-O - β - D-glucoside (R3G) has a clear chemical structure and unique physicochemical properties. It mainly exists in plants such as the Rhamnaceae and Leguminosae families, and can be obtained through mature extraction and separation techniques. In recent years, significant progress has been made in the pharmacological activity research of R3G, especially in the field of anti allergy, showing significant advantages in multi-target and multi pathway synergistic regulation. It can not only inhibit the release of allergic mediators and antagonize their receptors, but also inhibit the initiation and amplification of Th2 type immune responses upstream. Its mechanism of action covers multiple key targets such as ALOX5, HRH1, IL-4, STAT6, TSLP, etc. Its pharmacological evaluation shows that although there are challenges such as low oral bioavailability and potential genetic toxicity risks, its good water solubility, low hERG inhibition risk, and low blood-brain barrier penetration provide favorable conditions for its development.

In summary, R3G is a highly promising lead compound for anti allergic natural products. Future research should focus on further elucidating its molecular mechanisms, optimizing its pharmacokinetic properties, conducting comprehensive toxicological evaluations, and actively exploring its clinical translation pathways. With the continuous deepening of research, R3G is expected to provide a natural, novel, and safe treatment option for patients with allergic diseases, injecting new vitality into the field of natural product drug development.