Introduction/Overview
Natural products, as an important source of drug discovery, play an irreplaceable role in the long history of human fight against diseases. One of the key pathways in modern medicinal chemistry and pharmacology research is to isolate, identify, and elucidate the active ingredients from traditional herbs. Ophiopogon japonicus（Ophiopogon japonicus (L.f.) Ker-Gawl.）， As a commonly used traditional Chinese medicine that nourishes yin, moistens the lungs, and benefits the stomach and body fluids, its medicinal value has long been recorded in ancient Chinese herbal books such as the Shennong Bencao Jing. Modern pharmacological research has revealed that Ophiopogon japonicus and its active ingredients exhibit significant activities in cardiovascular system protection, anti-inflammatory, antioxidant, and immune regulation, particularly in the prevention and treatment of cardiovascular diseases such as myocardial ischemia and heart failure.
In the complex chemical composition system of Ophiopogon japonicus, steroidal saponins and high isoflavones are considered as the main pharmacological substances. However, in recent years, a class of monoterpenoid glycosides with relatively simple structures but unique activities has gradually entered the field of researchers. Borneol 7-O - [β - D-piofuranosyl - (1 → 6)] - β - D-glucopyranoside is a representative monoterpenoid glycoside isolated from Ophiopogon japonicus. This compound is composed of Borneol as a aglycone, which is linked by glycosidic bonds to a disaccharide chain consisting of β - D-furanosyl and β - D-glucopyranose. Longnao, also known as borneol, is a commonly used traditional Chinese medicine with the effects of opening the orifices, awakening the mind, clearing heat, and relieving pain. Its cardiovascular protective effects have also been widely studied. Combining dragon brain with specific sugar groups not only alters its physicochemical properties, but also potentially endows it with novel biological activity and pharmacokinetic characteristics.
In recent years, research on Ophiopogon japonicus glycoside has gradually deepened, especially in the field of anti myocardial ischemia. Multiple studies have revealed its potential to exert cardioprotective effects through multiple targets and pathways. The application of network pharmacology and molecular docking technology has further predicted and validated its interactions with multiple targets closely related to myocardial ischemic injury, oxidative stress, calcium overload, vasomotor function, and cell apoptosis, such as BCL2, HIF1A, SIRT1, ACE, NOS3, SOD2, SLC8A1, KCNJ2, AGTR1, etc. These findings not only provide modern scientific explanations for the traditional efficacy of Ophiopogon japonicus, but also provide candidate molecules for the development of new anti myocardial ischemia drugs. This article aims to provide a systematic review of the chemical structure, plant origin, pharmacological activity, mechanism of action, medicinal properties, and clinical application prospects of Ophiopogon japonicus glycoside, in order to provide reference for the in-depth research and development of this natural product.
Chemical structure and physicochemical properties
The chemical structure of Ophiopogon japonicus glycoside has distinct characteristics, with its core skeleton composed of a monoterpene compound, camphora, and a disaccharide chain connected by ether bonds. Borneol is a bicyclic monoterpene alcohol with the molecular formula C ₁₀ H ₁₈ O. It has two chiral centers and various stereoisomers, among which right-handed (+) - Borneol) and left-handed (-) - Borneol) are the most common. In Ophiopogon japonicus, the 7-hydroxyl group (- OH) of the dragon brain serves as a glycosylation site, forming a stable β - O-glycosidic bond with the reducing end of the sugar chain.
The sugar chain is composed of two monosaccharide units: β - D-glucopyranose on the inner side and β - D-furanosyl on the outer side. The two sugar units are connected by a (1 → 6) glycosidic bond, where the anomeric carbon (C1) of the outer furan sugar is dehydrated and condensed with the 6-position hydroxyl group of the inner glucose. This connection method is not common in natural products, especially in the presence of furan sugar, whose unique five membered ring furan structure endows the compound with special spatial conformation and physicochemical properties. Therefore, the systematic name of the compound is: Borneol 7-O - [β - D-piofuranosyl - (1 → 6)] - β - D-glucopyranoside.
From the perspective of physical and chemical properties, the molecular weight of Ophiopogon japonicus glycoside is 448.5090 g/mol, belonging to the small molecule glycoside class. Its lipid water partition coefficient (LogP) is -0.0320, indicating that the compound has an extremely low n-octanol/water partition coefficient, strong hydrophilicity, and is almost insoluble in lipid soluble media. This characteristic is closely related to the presence of multiple hydroxyl groups in its molecular structure (hydroxyl groups from the dragon brain and multiple hydroxyl groups on the sugar ring). The calculated topological polar surface area (TPSA) is 158.3000 Å ², much higher than the recommended upper limit of 140 Å ² for oral medications, indicating that it may be difficult to penetrate biological membranes, especially the blood-brain barrier, through passive diffusion. In fact, the evaluation of pharmacological parameters shows that its blood-brain barrier permeability is "low", which is consistent with its high polarity and large TPSA value. In terms of water solubility, the predicted value is 3.7190 mg/mL, indicating that it has a certain solubility in water, which provides a basis for its absorption and distribution in vivo. However, there is still a gap compared to ideal fully water-soluble drugs. In addition, the hERG inhibition prediction was "no", and the Ames test result was 0.0, indicating that the compound has a low risk of cardiac toxicity and genetic toxicity, and has a good safety basis. These physicochemical properties collectively determine the absorption, distribution, metabolism, and excretion (ADME) process of Ophiopogon japonicus glycoside in vivo, which is an important basis for subsequent pharmacokinetic studies and formulation design.
Plant sources and extraction methods
The main plant source of Longnao glycoside in Ophiopogon japonicus is Ophiopogon japonicus, a plant in the Liliaceae family（Ophiopogon japonicus）. Ophiopogon japonicus is widely distributed in East Asian regions such as China, Japan, and South Korea. Its dried tubers are the authentic source of traditional Chinese medicine Ophiopogon japonicus. In addition, plants of the same genus such as Hubei Ophiopogon japonicus（Liriope spicata var. prolifera）Hedong Mountain Ophiopogon japonicus（Liriope muscari）In some regions, it is also used as a substitute for Ophiopogon japonicus or as a local practice, but its chemical composition may vary, and the content of Ophiopogon japonicus Longin also needs further confirmation. Therefore, in order to ensure the accuracy and reproducibility of the research, it is necessary to clarify the botanical origin Ophiopogon japonicus crucial.
The content of Longnao glycoside in Ophiopogon japonicus is usually low and belongs to trace or trace components. The extraction and separation purification process requires the combination of modern chromatography technology to obtain compounds of sufficient purity and quantity for subsequent research. The classic extraction process usually includes the following steps:
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Raw material pretreatment and extraction Crush the dried Ophiopogon japonicus root tubers to an appropriate particle size and use solvent extraction method. Due to the high polarity of Ophiopogon japonicus glycosides, highly polar solvents such as methanol, ethanol, or water are usually used as extraction solvents. To improve extraction efficiency and selectivity, different concentrations of ethanol (such as 50% -80%) are often used for reflux extraction or cold soaking extraction. Ultrasound assisted extraction or microwave-assisted extraction can shorten the extraction time and improve the yield.
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Preliminary enrichment After the extraction solution is concentrated under reduced pressure, crude extract is obtained. The crude extract contains complex components, including a large amount of sugars, saponins, and high isoflavones. Usually, liquid-liquid extraction is used for preliminary separation, such as sequential extraction with petroleum ether, ethyl acetate, and n-butanol. Ophiopogon japonicus glycoside is mainly enriched in the n-butanol extraction layer or water layer due to its strong polarity.
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Chromatographic Separation and Purification The n-butanol extract or aqueous layer needs to be finely separated through various chromatographic techniques after concentration. Common methods include:
- Silica gel column chromatography Gradient elution using solvent systems such as chloroform methanol water can preliminarily separate glycoside components of different polarities.
- Macroporous adsorption resin column chromatography Models such as D101 and HP-20 utilize adsorption and desorption principles to effectively remove impurities such as sugars and enrich target glycosides.
- Gel column chromatography Such as Sephadex LH-20, which is separated based on molecular size and commonly used for removing pigments and further purification.
- Preparation type high performance liquid chromatography (Prep HPLC)This is a key step in obtaining high-purity Ophiopogon japonicus glycosides. By using a reverse phase C18 chromatography column with acetonitrile water or methanol water as the mobile phase and optimizing the gradient program, baseline separation of the target compound from structurally similar compounds can be achieved. The detection wavelength is usually selected between 200-210 nm (end absorption) or using an evaporative light scattering detector (ELSD).
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Structural Identification The isolated pure product needs to be structurally confirmed by spectroscopic methods, mainly including nuclear magnetic resonance spectroscopy (¹ H-NMR, ¹ ³ C-NMR, DEPT, COSY, HSQC, HMBC) and high-resolution mass spectrometry (HR-ESI-MS). By analyzing the terminal proton signal, coupling constant, and glycosidic bond connection position (HMBC related signal) of the sugar, its structure was ultimately confirmed to be Borneol 7-O - [β - D-piofuranosyl - (1 → 6)] - β - D-glucopyranoside.
Pharmacological activity research
Currently, research on the pharmacological activity of Ophiopogon japonicus glycoside mainly focuses on its cardiovascular system protective effect, especially its anti myocardial ischemia activity. Myocardial ischemia is caused by insufficient coronary artery blood supply, leading to hypoxia and energy metabolism disorders in myocardial cells, which in turn trigger a series of pathological and physiological changes, including oxidative stress, calcium overload, inflammatory response, and cell apoptosis. Ophiopogon japonicus glycoside exhibits protective effects on ischemic myocardium at multiple levels.
Anti myocardial ischemic injury In vitro cell models, the use of hypoxia/reoxygenation (H/R) or hydrogen peroxide (H ₂ O ₂) - induced myocardial cell (such as H9c2 cells or primary myocardial cells) injury models is a common method for evaluating anti myocardial ischemia activity. Research has shown that pretreatment with Ophiopogon japonicus glycoside can significantly improve the survival rate of damaged myocardial cells, reduce the release of lactate dehydrogenase (LDH) and creatine kinase (CK), suggesting its ability to stabilize cell membranes and alleviate cell damage. In the overall animal model, an acute myocardial infarction model was prepared by ligating the left anterior descending branch (LAD) of the coronary artery in rats, and treatment with Mai Dong Long Nao glycoside showed a significant reduction in myocardial infarction area, a decrease in ST segment elevation on electrocardiogram, and improvement in cardiac function indicators such as left ventricular ejection fraction (LVEF) and left ventricular short axis shortening rate (LVFS).
Antioxidant and anti apoptotic effects One of the core mechanisms of myocardial ischemia-reperfusion injury is oxidative stress. Ophiopogon japonicus glycoside can significantly enhance the activity of endogenous antioxidant enzymes such as superoxide dismutase (SOD2) and glutathione peroxidase (GSH Px) in myocardial cells, while reducing the levels of reactive oxygen species (ROS) and malondialdehyde (MDA). At the same time, it can effectively inhibit the apoptosis of myocardial cells. By regulating the expression of BCL2 family proteins, i.e. upregulating the expression of anti apoptotic protein BCL2 and downregulating the expression of pro apoptotic protein BAX, we can inhibit mitochondrial pathway apoptosis and reduce myocardial cell loss.
Improve energy metabolism and vascular function During myocardial ischemia, energy metabolism shifts from aerobic oxidation to anaerobic glycolysis, leading to insufficient ATP production and acidosis. Ophiopogon japonicus glycoside may activate energy receptors such as SIRT1 (silencing information regulatory factor 1), regulate downstream signaling molecules such as PGC-1 α, promote mitochondrial biosynthesis and fatty acid oxidation, and improve myocardial energy metabolism. In addition, its regulation of vascular function is also crucial. By upregulating the expression and activity of endothelial nitric oxide synthase (NOS3), promoting the production of nitric oxide (NO), exerting vasodilatory effects, and improving coronary artery blood flow. Meanwhile, the regulation of angiotensin-converting enzyme (ACE) and angiotensin II receptor type 1 (AGTR1) may help inhibit excessive activation of the renin-angiotensin system (RAS), alleviate vascular constriction and cardiac remodeling.
Adjust ion steady state Myocardial ischemia leading to intracellular calcium overload is an important cause of myocardial cell damage and arrhythmia. Ophiopogon japonicus glycoside may maintain the homeostasis of intracellular calcium and potassium ions, alleviate calcium overload, and reduce the risk of arrhythmia by regulating the functions of sodium calcium exchangers (SLC8A1) and inward rectifying potassium channels (KCNJ2). In addition, the regulation of hypoxia inducible factor 1 alpha (HIF1A) may be involved in the regulation of hypoxia adaptation and angiogenesis.
Mechanism of action and molecular targets
The anti myocardial ischemia effect of Ophiopogon japonicus glycoside cannot be fully explained by a single target or pathway, but exhibits a network regulatory feature of multi-target and multi pathway synergistic effects. Based on network pharmacology prediction and experimental verification, its core mechanism of action can be summarized as follows, involving targets such as BCL2, HIF1A, SIRT1, ACE, NOS3, SOD2, SLC8A1, KCNJ2, AGTR1, etc.
1. Regulating cell apoptosis and survival pathways (BCL2/HIF1A/SIRT1 axis)
The core pathological change of myocardial ischemia is myocardial cell death. Ophiopogon japonicus glycoside upregulates the expression of anti apoptotic protein BCL2, inhibits the opening of mitochondrial outer membrane permeability transition pore (mPTP), prevents cytochrome C release, thereby blocking the Caspase cascade reaction and exerting anti apoptotic effects. Meanwhile, it may activate SIRT1, deacetylate, and activate HIF1A. As a core transcription factor in hypoxia response, HIF1A can not only induce the expression of erythropoietin (EPO), vascular endothelial growth factor (VEGF), and other factors, promote angiogenesis and red blood cell generation, improve tissue oxygen supply, but also upregulate the expression of BCL2, further enhancing anti apoptotic ability. The activation of SIRT1 itself also has antioxidant, anti-inflammatory, and energy metabolism improving effects. Therefore, SIRT1-HIF1A-BCL2 forms an interconnected protective signaling network.
2. Anti oxidative stress pathway (SOD2/NOS3 axis)
Oxidative stress is one of the initiating factors of myocardial ischemia-reperfusion injury. Ophiopogon japonicus glycoside effectively clears superoxide anions and reduces ROS generation by upregulating the expression and activity of mitochondrial key antioxidant enzyme SOD2. Meanwhile, it can also upregulate the expression of NOS3 (eNOS) and promote the generation of NO. NO not only has strong vasodilation function, but also can directly clear ROS, inhibit leukocyte adhesion and platelet aggregation, and protect microvascular integrity. More importantly, NO can inhibit the activity of mitochondrial respiratory chain complex I, reduce electron leakage, and thus reduce ROS production from the source. Therefore, the synergistic upregulation of SOD2 and NOS3 constitutes the core mechanism of the antioxidant defense of Ophiopogon japonicus glycosides.
3. Regulating the renin-angiotensin system (ACE/AGTR1 axis)
The overactivation of the RAS system plays a crucial role in myocardial ischemia and cardiac remodeling. Angiotensin II (Ang II) induces strong vasoconstriction, promotes aldosterone secretion, and induces myocardial cell hypertrophy and fibrosis by binding to the AGTR1 receptor. Ophiopogon japonicus glycoside may inhibit the activity of ACE, reduce the production of Ang II, or directly antagonize AGTR1 receptors, thereby blocking the harmful effects of Ang II. This helps to lower blood pressure, alleviate cardiac afterload, inhibit myocardial fibrosis and ventricular remodeling, and has potential therapeutic value for chronic myocardial ischemia and heart failure.
4. Maintain ion homeostasis (SLC8A1/KCNJ2 axis)
During myocardial ischemia, intracellular Na ⁺ increases, and through the reverse mode of SLC8A1 (NCX), Na ⁺ is excreted while Ca ² ⁺ is pumped in, leading to calcium overload. Calcium overload activates calpain, damages cellular structure, and induces delayed depolarization (DAD) and triggering activity, leading to arrhythmia. Ophiopogon japonicus glycoside may reduce Ca ² ⁺ influx and alleviate calcium overload by inhibiting the reverse mode of SLC8A1. Meanwhile, the Kir2.1 channel encoded by KCNJ2 is a key inward rectifying potassium channel that maintains the resting membrane potential of myocardial cells. During ischemia, KCNJ2 function is downregulated, leading to depolarization of resting membrane potential and increased susceptibility to arrhythmia. Ophiopogon japonicus glycoside may exert antiarrhythmic effects by upregulating the expression or function of KCNJ2, stabilizing membrane potential.
In summary, Ophiopogon japonicus glycoside forms a synergistic protective network by acting on multiple key targets such as apoptosis, oxidative stress, RAS system, and ion homeostasis, thus comprehensively and effectively combating myocardial ischemic injury.
Evaluation of drug properties and pharmacokinetics
The development of natural products into clinical drugs must undergo strict pharmacological evaluation. The physicochemical properties of Ophiopogon japonicus glycoside have preliminarily outlined its pharmacological profile. Its molecular weight (448.5 Da) is within the range of small molecule drugs, but the LogP is negative (-0.032), the TPSA is as high as 158.3 Å ², and the water solubility is moderate (3.72 mg/mL). These data indicate that the compound belongs to a typical molecule with high polarity, good water solubility, and poor lipid solubility, meeting the requirements for LogP and molecular weight in Lipinski's Rule of Five. However, its TPSA value is relatively high, suggesting that its oral bioavailability may be low and it may be difficult to penetrate the blood-brain barrier. The negative results of hERG inhibition and Ames test provide preliminary assurance for its safety.
Regarding its pharmacokinetic (ADME) characteristics, there is currently a lack of systematic in vivo research data, but reasonable speculation can be made based on its physicochemical properties:
- absorb Due to its high polarity and low LogP, the ability of Ophiopogon japonicus glycoside to passively diffuse through intestinal epithelial cells is poor. Its oral absorption may mainly rely on active transport or facilitated diffusion mediated by intestinal transporters such as glucose transporters GLUTs or sodium dependent glucose transporters SGLTs. Therefore, its oral bioavailability may not be high. Strategies to improve oral absorption may include designing prodrugs, using absorption enhancers, or developing non oral routes of administration (such as injections).
- distribution Due to its strong hydrophilicity, Ophiopogon japonicus glycoside is mainly distributed in plasma and extracellular fluid, and its binding rate with plasma proteins may be low. Its distribution volume may be small. Low blood-brain barrier permeability means limited potential for its application in central nervous system diseases, but for the treatment of peripheral diseases such as cardiovascular disease, this may actually reduce central side effects.
- Metabolism As a glycoside compound, Ophiopogon japonicus glycosides may undergo two main metabolic pathways in the body: one is hydrolysis by gut microbiota or hepatic glycosidases, releasing aglycones such as camptothecin and disaccharide chains. Dragon brain itself has pharmacological activity, and its metabolites may further participate in the efficacy of the drug. The second possibility is that the sugar chain may undergo further oxidation, reduction, or binding reactions. The liver cytochrome P450 enzyme system may be involved in the metabolism of its glycoside moiety.
- excretion Due to its high polarity and low molecular weight, Ophiopogon japonicus glycosides and their metabolites (especially glucuronic acid or sulfate conjugates of aglycone camphora) are likely to be mainly excreted in urine through the kidneys in their original form or metabolite form. Bile excretion may also be one of its clearance pathways.
Overall, Ophiopogon japonicus glycoside has a certain pharmacological basis, especially in terms of safety performance. But its oral bioavailability may be a key bottleneck that needs to be overcome through modern medicinal chemical methods such as structural modification and dosage form design. For example, preparing it into phospholipid complexes, nanoparticles, or cyclodextrin inclusion complexes may effectively improve its oral absorption. In addition, developing its intravenous injection form for direct clinical treatment of acute myocardial ischemia is also a direction worth exploring.
Clinical application prospects and prospects
Based on the clear anti myocardial ischemia activity and multi-target mechanism of action of Ophiopogon japonicus glycoside, it has shown broad application prospects in the field of cardiovascular disease treatment.
1. Adjuvant therapy for acute myocardial infarction In reperfusion therapy (such as thrombolysis and PCI) after acute myocardial infarction, myocardial ischemia-reperfusion injury is a key factor leading to the expansion of myocardial infarction area and deterioration of cardiac function. The strong antioxidant, anti apoptotic, and anti-inflammatory effects of Ophiopogon japonicus glycoside make it an ideal reperfusion injury protector. Developing its intravenous injection form and administering it before or simultaneously with reperfusion therapy may significantly reduce the area of myocardial infarction and improve prognosis.
2. Long term management of chronic myocardial ischemia and heart failure The regulatory effect of Ophiopogon japonicus glycoside on the RAS system and its improvement on energy metabolism and vascular function suggest that it may be suitable for long-term treatment of chronic myocardial ischemia and chronic heart failure. It may delay the progression of heart failure by upregulating SIRT1, improving mitochondrial function, inhibiting cardiac remodeling, and other mechanisms. If the problem of oral bioavailability can be solved and developed into oral preparations, it will have enormous clinical application value.
3. Prevention and treatment of arrhythmia By regulating targets such as SLC8A1 and KCNJ2 to maintain ion homeostasis in myocardial cells, Ophiopogon japonicus glycoside may have the potential to treat arrhythmias, especially ischemic arrhythmias. This provides new ideas for its application in the field of cardiac electrophysiology.
Future research directions：
Despite the bright prospects, the research on Ophiopogon japonicus glycoside is still in its early stages, and there are still many challenges to overcome before clinical application:
- In depth pharmacokinetic research It is urgent to conduct systematic in vivo ADME research to clarify its oral bioavailability, metabolic pathways, major metabolites and their activities, tissue distribution, and excretion characteristics. This is the basis for conducting subsequent pharmacological and toxicological studies.
- Comprehensive toxicological evaluation Although the preliminary Ames test and hERG prediction results are good, a complete preclinical toxicology study is still needed, including acute toxicity, long-term toxicity, reproductive toxicity, and immunotoxicity, to comprehensively evaluate its safety.
- In depth elucidation of the mechanism of action Although multiple targets have been predicted and validated, their direct binding modes, binding kinetics, and precise regulatory mechanisms of downstream signaling networks still need to be further elucidated through molecular biology, structural biology, and other methods. For example, the binding constant between it and the target protein can be determined by surface plasmon resonance (SPR) or isothermal titration calorimetry (ITC).
- Pharmaceutical Chemistry and Formulation Optimization To address the bottleneck of poor oral absorption, it is necessary to carry out structural modifications through medicinal chemical methods, such as designing prodrugs, introducing specific functional groups to improve lipid solubility, or developing new drug delivery systems (such as nanoliposomes, polymer micelles, phospholipid complexes, etc.) to enhance their bioavailability.
- Study on Structure Activity Relationship Synthesize a series of analogs of Longan glycosides, systematically study the effects of sugar chain length, sugar group type, connection mode, and changes in glycoside structure on their activity and pharmacokinetic properties, and provide guidance for finding better candidate molecules.
Conclusion
As a natural monoterpene glycoside derived from traditional Chinese medicine Ophiopogon japonicus, Ophiopogon japonicus Longnao glycoside provides valuable lead molecules for modern cardiovascular drug development due to its unique chemical structure and clear anti myocardial ischemia activity. It exerts synergistic protective effects in anti apoptosis, antioxidant, regulating RAS system and maintaining ion homeostasis by regulating multiple targets such as BCL2, HIF1A, SIRT1, ACE, NOS3, SOD2, SLC8A1, KCNJ2, AGTR1, etc., reflecting the advantages of natural product multi-target and overall regulation. Although there are challenges in terms of oral bioavailability, its good safety foundation and clear pharmacological activity make it a promising new type of anti myocardial ischemia drug. Future research should focus on in-depth analysis of pharmacokinetics, toxicology, mechanisms of action, as well as optimization of drug chemistry and dosage forms, in order to bring this natural product from the laboratory to clinical practice and provide new treatment options for cardiovascular disease patients. The research process of Ophiopogon japonicus glycoside once again confirms the scientific value and practical significance of excavating modern drug molecules from the treasure trove of traditional Chinese medicine.
![Borneol 7-O-[β-D-apiofuranosyl-(1→6)]-β-D-glucopyranoside](/upload/0201/05/88700-35-0.png)
