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

Introduction/Overview

Uridine (CAS number 58-96-8), as a basic ribonucleoside, plays an important biological role in living organisms. It consists of a urocil base connected to furan ribose via a β-N1 glycosidic bond, and is one of the basic units for nucleic acid synthesis. Uridine not only participates in the synthesis and metabolism of nucleic acids but also serves as a key intermediate in various biosynthetic pathways, widely present in animals and plants. In recent years, research on uridine in pharmacology has deepened, revealing its potential applications in antiviral, neuroprotection, and metabolic regulation. This paper will systematically review the chemical structure and physicochemical properties of uracil nucleosides, plant origins and extraction methods, pharmacological activity and mechanism of action, druggability evaluation, pharmacokinetic characteristics, and clinical application prospects, aiming to provide a theoretical foundation and practical guidance for pharmacological research of natural products.

Chemical structure and physicochemical properties

The chemical structure of uracil ribosides consists of a uracil base and a pentacrose (furan ribose) connected by β-N1-glycosidic bonds. Its molecular formula is C9H12N2O6, and its molecular weight is 244.2030. In the structural formula, the uracil ring is a pyrimidine nitrogen-containing base with two nitrogen atoms and two carbonyl groups, giving it strong polarity and hydrogen bond formation ability. The hydroxyl group in the furanose portion provides water solubility and biocompatibility.

In terms of physicochemical properties, uracil nucleoside has a LogP value of -1.8621, indicating high hydrophilicity, with a water solubility of 63.8493 mg/mL, indicating it is easily soluble in water but poorly soluble in fat-soluble solvents. The polar surface area (TPSA) is 124.78 Ų, indicating strong polarity and hydrogen bond acceptor capability. Uridine has low blood-brain barrier permeability, limiting its potential to act directly on the central nervous system. Additionally, uridine does not exhibit hERG channel inhibitory activity, indicating a lower risk of cardiotoxicity. The Ames test result was 1.2, indicating a low genotoxicity risk and good safety.

Plant Origins and Extraction Methods

Uracil nucleosides are widely present in various plants and organisms, especially in plant tissues rich in nucleic acids. Common sources include grains, legumes, leafy vegetables, and certain medicinal plants. Because it is a natural product of nucleosides, it usually exists in free form or as hydrolyzed nucleic acid products.

Traditional extraction methods mainly rely on a combination of water extraction and alcohol extraction. The specific steps include: crushing plant raw materials, extracting them with hot water or buffer, then removing macromolecular impurities through alcohol precipitation, and finally using chromatography techniques (such as ion exchange chromatography and reversed-phase high-performance liquid chromatography) to separate and purify uridine. In modern technology, ultrasound-assisted extraction and enzymatic hydrolysis methods are also applied to improve extraction efficiency and purity.

In addition, uracil nucleosides can also be obtained through microbial fermentation or chemical synthesis, especially in industrial production, where fermentation is widely adopted due to its efficiency and environmental friendliness.

Pharmacological activity research

Pharmacological research on uricil nucleoside mainly focuses on its antiviral activity, neuroprotective effects, and metabolic regulatory functions.

Antiviral activity

Uridine and its derivatives inhibit various viruses, especially DNA viruses and retroviruses. Its targets include various viral proteins, including myeloperoxidase (MPO), herpes virus-related proteins UL42, UL54, ICP27, thymidine kinase (TK), viral glycoprotein D (gD), as well as HIV-related CCR5, CXCR4 receptors, HIV-1 protease (HIV-PR), and integrase (INT). Uridine inhibits viral proliferation and transmission by interfering with viral nucleic acid synthesis, protein translation, and viral replication.

Neuroprotective effects

As an important component of nucleotide metabolism in the brain, uridine participates in the synthesis of phospholipids in nerve cell membranes, promoting neuronal repair and regeneration. Research shows that uridine can regulate neurotransmitter release, enhance neuronal metabolic activity, and exert antidepressant, cognitive function, and protective effects against neurodegenerative diseases.

Metabolic regulation function

Uridine participates in pyrimidine nucleotide metabolism, regulating energy metabolism and cellular signaling. Its regulatory role in abnormal glucose and lipid metabolism, inflammatory responses, and apoptosis suggests its potential application value in metabolic syndrome and inflammatory diseases.

Mechanism of action and molecular targets

The pharmacological mechanism of uracil nucleosides is mainly based on their biological function as nucleotide metabolites and their inhibitory effects on virus-related proteins.

In terms of antiviral activity, uridine competitively inhibits the activity of viral DNA polymerase and related enzymes, thereby blocking the synthesis of viral nucleic acids. It binds to the herpesvirus UL42 and UL54 proteins, inhibiting the assembly and function of viral replication complexes. For HIV virus, uridine affects the viral invasion process mediated by CCR5 and CXCR4 receptors, blocking the binding and fusion of viruses with host cells. Additionally, uridine inhibits HIV1 protease and integrase, interferes with viral protein maturation and genomic integration, significantly reducing viral load.

In neuroprotection, uridine acts as a precursor to phospholipid synthesis, promoting the repair and regeneration of nerve cell membranes. By regulating intracellular signaling pathways such as MAPK and PI3K/Akt pathways, it enhances neuronal survival and functional recovery. Uridine can also regulate the synthesis and release of neurotransmitters, improving nerve conduction efficiency.

In terms of metabolic regulation mechanisms, uridine is involved in regulating the intracellular ATP/ADP ratio, affecting the balance of energy metabolism. Its regulatory effect on inflammatory signaling molecules reduces cellular stress and apoptosis, maintaining tissue homeostasis.

Druggability evaluation and pharmacokinetics

The druggability parameters of uracil nucleoside indicate good drug development potential. Its molecular weight of 244.2030 falls within the ideal range for drug molecular weight. A negative LogP value (-1.8621) indicates strong hydrophilicity, suitable for the development of water-soluble formulations, but may limit their passive diffusion through lipid membranes.

The polar surface area (TPSA) was 124.78 Ų, indicating high polarity that may affect oral bioavailability and tissue distribution. High water solubility (63.8493 mg/mL) facilitates the dissolution and absorption of the formulation. The low permeability of the blood-brain barrier limits its direct application in central nervous system diseases, but intracranial delivery can be achieved through structural modification or delivery system optimization.

In terms of safety, uridine does not inhibit hERG channels, reducing the risk of cardiotoxicity. Ames test results showed low genotoxicity and relatively high safety.

Pharmacokinetic studies show that uridine is rapidly absorbed after oral administration, with a short plasma half-life and is mainly excreted by the kidneys. In the body, it can be rapidly metabolized into urasine and related nucleotides, participating in various metabolic pathways. The bioavailability of uridine is influenced by gastrointestinal enzymatic hydrolysis and cell membrane transporters; future drug designs need to consider improving its stability and targeting.

Prospects and outlooks for clinical applications

Due to its multiple biological functions, uracil nucleoside has broad clinical application potential. Its antiviral activity makes it a candidate drug for treating herpesvirus, HIV, and other viral infections. By integrating modern drug design technologies, uridine derivatives can optimize targeting and efficacy, enhancing clinical efficacy.

In the field of neuroprotection, uridine acts as an adjunct in nerve repair and holds potential for treating neurodegenerative diseases, brain injury, and cognitive impairment. Its safety and biocompatibility advantages help in developing long-term medication regimens.

Moreover, uridine's regulatory role in metabolic and inflammatory diseases opens the possibility for expanding new indications. In the future, combining nanocarriers, targeted delivery technologies, and structural modification is expected to significantly improve the pharmacokinetic performance and therapeutic efficacy of uridine.

Although uridine demonstrates good pharmacological activity and safety, further systematic clinical trials are needed to verify its efficacy and safety, and to clarify its optimal administration route and dosage regimen. At the same time, in-depth exploration of its molecular mechanisms and metabolic pathways helps guide new drug development and clinical application.

Conclusion

As a natural ribonucleoside, uracil nucleoside demonstrates significant value in the field of natural product pharmacology due to its unique chemical structure and diverse biological functions. Its multiple pharmacological activities—antiviral, neuroprotective, and metabolic regulation—provide a solid foundation for its clinical application. Druggability evaluations show that uridine has good safety and drug development potential, but its physicochemical properties pose challenges to pharmacokinetics, which must be overcome through drug design and delivery technologies.

In the future, by combining modern molecular biology and medicinal chemistry techniques, uridine and its derivatives are expected to become novel drugs for treating various diseases. Systematic clinical research and mechanism exploration will promote the transformation of uridine from basic research to clinical application, fostering the development and innovation of natural product pharmacology.