Endogenous Metabolite

Zinc Protoporphyrin (Zn(II)-protoporphyrin IX) is a competitive heme oxygenase-1 (HO-1) inhibitor, markedly attenuates the protective effects of Phloroglucinol (PG) against H2O2.

3-Methyluridine is a modified nucleoside of cellular RNA.

Prostaglandin E1 (PGE1) is the theoretical cyclooxygenase metabolite of dihomo-γ-linolenic acid (DGLA), but it is virtually undetectable in the plasma of normal humans or other animals. The IC50 of PGE1 for the inhibition of ADP-induced human platelet aggregation is 40 nM.

17-Hydroxyprogesterone is an endogenous progestogen as well as chemical intermediate in the biosynthesis of other steroid hormones, including the corticosteroids and the androgens and the estrogens.

L-Citrulline is an amino acid derived from ornithine in the catabolism of proline or glutamine and glutamate, or from l-arginine via arginine-citrulline pathway.

Nicotinamide riboside chloride is a crystal form of Nicotinamide riboside (NR) chloride. Nicotinamide riboside chloride is used in dietary supplements.

Berberine hydrochloride was novelly found that it has various beneficial effects on the cardiovascular system and significant anti-inflammatory activities. Berberine can effectively reduce intracellular superoxide levels in LPS-stimulated macrophages. Such a restoration of cellular redox by berberine is mediated by its selective inhibition of gp91phox expression and enhancement of SOD activity.

Prednisolone is a glucocorticoid with the general properties of the corticosteroids.

Xenin is a 25-amino acid peptide initially isolated from human gastric mucosa. Xenin is a gut hormone that can reduce food intake.

N-Acetyloxytocin is isolated and characterized in the neurointermediate lobe of the rat pituitary (NIL) and their presence in several brain areas of the rat.

γ-Glu-Gly, a γ-glutamyl dipeptide, is a human lipid metabolite.γ-Glu-Gly has a similar structure to GABA (γ-aminobutyric acid) and can act as an antagonist of excitatory amino acids.

L-LEUCINE-13C6, also known as 13C6-D-Leucine or L-Leucine-1,2,3,4,5,5'-13C6, is a fully 13C labelled D-Leucine. L-Leucine is an essential branched-chain amino acid (BCAA), which activates the mTOR signaling pathway.

Xanthurenic acid is a putative endogenous Group II metabotropic glutamate receptor agonist, on sensory transmission in the thalamus.

Ergothioneine is an endogenous metabolite that acts as a potent antioxidant. It functions primarily as a specific inhibitor of p38 MAPK and Akt, which are critical signaling pathways involved in cellular stress responses. Ergothioneine is utilized in research focused on neuroprotection, cell apoptosis, and oxidative stress, making it a valuable compound for investigations into cellular resilience and health.

Atranorin is a secondary metabolite derived from lichens that acts as an AKT inhibitor. This compound demonstrates a wide range of biological activities, including antibacterial, anti-inflammatory, antioxidant, anti-glycation, analgesic, and anti-tumor effects. Notably, Atranorin has IC50 values of 117 μM for scavenging DPPH free radicals and less than 10 μM for ABTS radicals, highlighting its potent antioxidant capacity. Additionally, Atranorin promotes wound healing and can be utilized in research focused on myelodysplastic syndromes, tumors, and various inflammatory conditions.

9-cis-Retinal is a natural retinoid that serves as a crucial signaling molecule in visual processes. It is produced from dietary 9-cis-β-carotene through enzymatic cleavage. This compound exhibits high-affinity binding to cellular retinol-binding proteins CRBP-I and CRBP-II, with dissociation constants of 8 nM and 5 nM, respectively. 9-cis-Retinal plays a significant role in promoting differentiation and maturation of rod photoreceptors in retinal organoid models, making it valuable for research in vision science and photoreceptor development.

Estradiol (β-Estradiol) is a steroid hormone and the major female sex hormone. Estradiol can up-regulate the expression of neural markers of human endometrial stem cells (hEnSCs) and promote their neural differentiation. Estradiol can be used for the research of cancers, neurodegenerative diseases and neural tissue engineering.

L-DOPA (Levodopa) is an orally active metabolic precursor of neurotransmitters dopamine. L-DOPA can cross the blood-brain barrier and is converted into dopamine in the brain. L-DOPA has anti-allodynic effects and the potential for Parkinson's disease.

Nicotinamide is a form of vitamin B3 or niacin. Nicotinamide Hydrochloride inhibits SIRT2 activity (IC50: 2 μM). Nicotinamide also inhibits SIRT1. Nicotinamide increases cellular NAD+, ATP, ROS levels. Nicotinamide inhibits tumor growth and improves survival. Nicotinamide also has anti-HBV activity.

Corticosterone (17-Deoxycortisol) is an orally active and adrenal cortex-produced glucocorticoid, which plays an important role in regulating neuronal functions of the limbic system (including hippocampus, prefrontal cortex, and amygdala). Corticosterone increases the Rab-mediated AMPAR membrane traffic via SGK-induced phosphorylation of GDI. Corticosterone also interferes with the maturation of dendritic cells and shows a good immunosuppressive effect.

Oleic acid (9-cis-Octadecenoic acid) is an abundant monounsaturated fatty acid. Oleic acid is a Na+/K+ ATPase activator.

Docosahexaenoic Acid (DHA) is an omega-3 fatty acid abundantly present brain and retina. It can be obtained directly from fish oil and maternal milk.

ATP (Adenosine 5'-triphosphate) is a central component of energy storage and metabolism in vivo. ATP provides the metabolic energy to drive metabolic pumps and serves as a coenzyme in cells. ATP is an important endogenous signaling molecule in immunity and inflammation. ATP can activate the NLRP3 inflammasome and induce IL-1β and chemokines secretion. ATP has anti-bacterial infection effects and can protect mice against bacterial infection in mice.

Hyaluronic acid sodium, also known as sodium hyaluronate, is a glycosaminoglycan that plays a crucial role in the extracellular matrix (ECM). This biopolymer is involved in key biological activities such as cell proliferation, tissue remodeling, and angiogenesis, particularly in the context of digestive cancers. Hyaluronic acid sodium is implicated in tumor cell growth and migration, and it activates the PI3K-Akt signaling pathway. This reagent can also be utilized in research related to joint diseases, wound healing, and as a drug delivery system to enhance the efficacy of therapeutics in cancer research.

Liothyronine is an active form of thyroid hormone that primarily targets thyroid hormone receptors TRα and TRβ. It exhibits binding affinities of 2.33 nM and 2.29 nM for human TRα and TRβ, respectively. In addition, Liothyronine binds to PVR and effectively inhibits the interaction between TIGIT and PVR. This compound is useful in research applications related to thyroid hormone signaling and immune modulation studies.

Taurochenodeoxycholic acid is an endogenous metabolite primarily involved in bile acid metabolism. It exhibits significant biological activities, including the induction of apoptosis and anti-inflammatory effects, alongside immune regulatory properties. This compound serves as a valuable tool in research applications related to metabolic disorders, inflammation, and immune response studies.

N-Acetyl-L-tryptophan is an antagonist of the neurokinin-1 receptor (NK-1R), effectively disrupting the binding of substance P, which leads to neuroprotective outcomes. This compound is known to improve cognitive function and motor skills while also acting as an inhibitor of cytochrome c, exhibiting antioxidant and anti-inflammatory properties through the regulation of IL-1β expression and caspase-1 activation. N-Acetyl-L-tryptophan is valuable for research investigating neurodegenerative and inflammatory conditions.

Crocin is an endogenous metabolite derived from the stigma of Crocus sativus, recognized for its role in inhibiting tumor cell proliferation and promoting apoptosis via the JAK signaling pathway. It exhibits significant anti-inflammatory and antioxidant properties, making it a valuable compound for research in cancer biology and therapeutic development. Crocin is utilized in studies focused on its potential as an antitumor agent and its broader implications in cellular health.

Phosphocreatine is an endogenous metabolite primarily known for its role in energy metabolism within vertebrate skeletal muscle. It enhances antioxidant activity and activates the TAK1 pathway, contributing to cardiac protection. Additionally, phosphocreatine normalizes mitochondrial function and mitigates oxidative stress through the Akt-mediated Nrf2/HO-1 pathway. Furthermore, it provides renal protection by inhibiting apoptosis and reactive oxygen species (ROS) generation via the ERK-mediated Nrf2/HO-1 pathway, making it a valuable tool for research in cellular stress responses and organ protection.

N1-Acetylspermidine hydrochloride is an acetyl derivative of polyamines, serving as a substrate for polyamine oxidase (PAO). It has been shown to promote apoptosis, particularly in conjunction with procyanidins, and demonstrates cleavage efficiency at apurinic sites in DNA. This compound has valuable applications in colorectal cancer research, facilitating investigations into polyamine metabolism and its implications in tumorigenesis.

Linolelaidic acid is an omega-6 trans fatty acid that functions as an endogenous metabolite with critical roles in human physiology. This compound exhibits anti-inflammatory and anti-parasitic activities, and has been shown to induce apoptosis in various cell types. Linolelaidic acid is relevant for research applications in the study of infections and nutritional science, particularly concerning enteral and parenteral nutrition as well as infant formula development.

6-Oxolithocholic acid is an endogenous bile acid metabolite primarily involved in bile acid metabolism and cholesterol synthesis regulation. It exhibits significant cytotoxic effects and can induce apoptosis in hepatocytes. This compound is valuable for research into the roles of bile acids in various health conditions, particularly in the context of digestive and liver diseases.

NNK is a tobacco-specific nitrosamine derived from nicotine and is a well-established carcinogenic compound. It activates both ERK1/2 and PKCα signaling pathways, leading to phosphorylation of Bcl-2 at Ser70 and c-Myc at Thr58 and Ser62, thereby promoting cell survival and proliferation in human lung cancer cells. Due to its strong tumorigenic potential, NNK is widely used to induce lung cancer in experimental mouse models for studying carcinogenesis and evaluating anticancer therapeutics.

Pyridoxal 5′-phosphate monohydrate is the active coenzyme form of vitamin B6 and is essential for the function of numerous enzymes. It serves as a key cofactor for aromatic L-amino acid decarboxylase, which catalyzes the final step in the biosynthesis of the neurotransmitters dopamine and serotonin. Pyridoxal 5′-phosphate is the primary intracellular phosphorylated form of vitamin B6 and is interconvertible with other forms, including pyridoxine 5′-phosphate (PNP) and pyridoxamine 5′-phosphate (PMP).

ATP (Adenosine 5'-triphosphate) dimagnesium is a key molecule in cellular energy storage and metabolism. It supplies metabolic energy for ion pumps and other enzymatic processes and functions as a coenzyme in numerous cellular reactions. Additionally, ATP dimagnesium acts as an important endogenous signaling molecule involved in immune and inflammatory responses.

5-Methyl-2'-deoxycytidine (5mdC) is an endogenous substrate of DNA methyltransferases, including mammalian 5-C-MTase, and binds to DNA in a manner dependent on DNA stem-loop structure formation. It directs de novo DNA methylation by serving as a methylation mark, promoting methylation of adjacent CpG sites in single-stranded DNA via cis-acting mechanisms. 5mdC regulates DNA methylation patterns by recruiting methyltransferases to specific chromatin regions, influencing chromatin condensation and gene expression. In plant cells, its distribution correlates with cell proliferation and differentiation stages, with lower methylation levels in proliferating cells and higher levels in differentiated cells.

Triolein is a symmetric triacylglycerol composed of three oleic acid molecules esterified to glycerol. It exhibits strong antioxidant and anti-inflammatory properties and has been shown to reduce the upregulation of matrix metalloproteinase-1 (MMP-1), a key enzyme involved in tissue remodeling and inflammation. These activities make triolein a compound of interest in research related to inflammatory diseases and oxidative stress.

Enrofloxacin monohydrochloride (BAY Vp 2674 monohydrochloride) is a broad-spectrum antibiotic with demonstrated efficacy against *Mycoplasma bovis*, exhibiting a MIC₉₀ of 0.312 μg/mL. In addition to its antibacterial properties, it also shows inhibitory activity against vaccinia virus (VV), indicating potential antiviral applications.

C16-PAF (PAF (C16)) is a phospholipid mediator and a potent platelet-activating factor that functions as a ligand for the PAF G-protein-coupled receptor (PAFR). It exhibits anti-apoptotic effects by inhibiting caspase-dependent cell death through PAFR activation. C16-PAF is a strong activator of the MAPK and MEK/ERK signaling pathways and is known to induce increased vascular permeability.

Gondoic acid (cis-11-Eicosenoic acid) is a monounsaturated long-chain fatty acid found in various plant oils and nuts. It exhibits anti-inflammatory activity by reducing reactive oxygen species (ROS) production and inhibiting the PKCθ/ERK/STAT3 signaling pathway. Gondoic acid is also utilized as a raw material in medical applications and as a moisturizing agent in cosmetic formulations.

Tauroursodeoxycholate (Tauroursodeoxycholic acid; TDUCA) dihydrate is an inhibitor of endoplasmic reticulum (ER) stress that significantly downregulates pro-apoptotic molecules, including caspase-3 and caspase-12. Additionally, it suppresses ERK signaling, contributing to its cytoprotective and anti-apoptotic effects.

Pyridoxal 5′-phosphate hydrate (PLP) is the biologically active form of vitamin B6 and serves as an essential cofactor for over 100 enzymatic reactions, particularly those involved in amino acid metabolism. It plays a critical role in the function of aromatic L-amino acid decarboxylase, the enzyme responsible for catalyzing the final step in the synthesis of key neurotransmitters such as dopamine and serotonin. PLP is the principal coenzyme form generated through intracellular phosphorylation of vitamin B6 precursors and is interconvertible with other phosphorylated forms, including pyridoxine 5′-phosphate (PNP) and pyridoxamine 5′-phosphate (PMP).

Deltonin is a steroidal saponin isolated from *Dioscorea zingiberensis*, exhibiting notable antitumor activity. It exerts its effects by inhibiting the activation of key survival and proliferation pathways, specifically ERK1/2 and AKT signaling. Through this dual inhibition, Deltonin suppresses tumor cell growth and promotes apoptosis, making it a promising candidate for further investigation in cancer research and therapeutic development.

Gamma-linolenic acid (γ-linolenic acid, GLA) is an orally active omega-6 unsaturated fatty acid with broad pharmacological activities. It exhibits anti-inflammatory effects by inhibiting the NF-κB signaling pathway and suppressing the phosphorylation of ERK1/2 and JNK, key mediators of inflammatory responses. GLA also induces apoptosis in cancer cells, contributing to its anticancer potential. Additionally, it possesses antioxidant properties and has been shown to improve memory function, suggesting neuroprotective benefits. These multifunctional effects position gamma-linolenic acid as a promising compound for research in inflammation, oncology, and neurological disorders.

Triacetin (Glyceryl triacetate) is an orally active synthetic triester of glycerol and acetic acid that serves as a bioavailable source of acetate. It freely crosses the blood–brain barrier and cellular membranes, making it particularly effective in targeting central nervous system malignancies. In glioma cells, Triacetin increases intracellular acetate levels, promotes histone acetylation, and induces cell cycle arrest and apoptosis. Additionally, Triacetin enhances the chemotherapeutic efficacy of Temozolomide (TMZ), supporting its potential as an adjuvant in glioma treatment strategies.

Phosphocreatine disodium is an endogenous metabolite primarily recognized for its involvement in energy metabolism within vertebrate skeletal muscles. This compound enhances antioxidant activity and activates the TAK1 pathway, offering cardioprotective effects. Additionally, it normalizes mitochondrial function and mitigates oxidative stress through the Akt-mediated Nrf2/HO-1 signaling pathway, while also providing renal protection by suppressing apoptosis and reactive oxygen species generation via the ERK-mediated Nrf2/HO-1 pathway. Phosphocreatine disodium is valuable for research investigating cellular energy dynamics and oxidative stress responses.

Creatine monohydrate, an endogenous metabolite, primarily functions as a critical regulator of cellular energy homeostasis. Its key biological activity includes the enhancement of ATP synthesis, which is essential for energy production in muscle and brain tissues. This compound is widely utilized in research related to energy metabolism, neuroprotection, and athletic performance enhancement.

Phosphocreatine dipotassium is an endogenous metabolite that serves as a critical energy reservoir in vertebrate skeletal muscles. It enhances antioxidant activity and activates the TAK1 pathway, providing cardioprotective effects. Furthermore, phosphocreatine normalizes mitochondrial function and mitigates oxidative stress via the Akt-mediated Nrf2/HO-1 pathway. It also offers renal protection by suppressing apoptosis and reactive oxygen species generation through the ERK-mediated Nrf2/HO-1 pathway, making it a valuable reagent for studies in cellular metabolism and oxidative stress.

Creosol (2-Methoxy-4-methylphenol) is an endogenous metabolite that serves as a significant chemical intermediate and a potential biofuel derived from lignocellulosic biomass. Its ability to penetrate the blood-brain barrier enhances its relevance in neurobiological research and metabolic studies. Creosol may be utilized in exploring biochemical pathways and developing greener energy alternatives, making it a valuable tool for scientific investigations in these areas.

Phosphocreatine disodium hydrate is an endogenous metabolite primarily involved in energy metabolism within vertebrate skeletal muscles. This compound enhances antioxidant activity and activates the TAK1 pathway, contributing to cardiac protection. Additionally, it normalizes mitochondrial function and mitigates oxidative stress through the Akt-mediated Nrf2/HO-1 pathway. Phosphocreatine disodium hydrate also exhibits renal protective effects by suppressing apoptosis and reactive oxygen species generation via the ERK-mediated Nrf2/HO-1 pathway.