AdoHcy hydrolase ( IC50 = 40 nM )
The target of Adenosine Dialdehyde (ADOX) is S-adenosylhomocysteine hydrolase (SAHH) (Ki = 0.4 nM for rat liver SAHH; Ki = 0.2 nM for human placental SAHH)[1]
The target of Adenosine Dialdehyde (ADOX) is S-adenosylhomocysteine hydrolase (SAHH)[2]
No target information of Adenosine Dialdehyde (ADOX) is described in the literature[3]
The target of Adenosine Dialdehyde (ADOX) is S-adenosylhomocysteine hydrolase (SAHH) (IC₅₀ = 10 nM for recombinant human SAHH)[4]

AdOx, when given by steady state infusion, does not suppress hematopoiesis and has a strong inhibitory effect on the in situ growth of established murine neuroblastoma (MNB) tumors. It also extends the life span of tumor-bearing mice. AdOx given intraperitoneally at a dose of 20 mg/kg/day until death inhibits the replication of L1210 leukemia cells and increases life span by about 40%[3].

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1. Antitumor activity in murine leukemia models: Intraperitoneal administration of Adenosine Dialdehyde (ADOX) at 1 mg/kg/day for 5 consecutive days significantly inhibits the growth of L1210 leukemia cells in DBA/2 mice, increasing the median survival time from 10 days to 25 days[1]
2. Effect on SAM/SAH ratio in vivo: Intraperitoneal injection of 1 mg/kg ADOX to rats results in a 50% decrease in liver SAM levels and a 3-fold increase in liver SAH levels within 4 hours, leading to a significant reduction in the SAM/SAH ratio[1]
1. Antitumor activity in human xenograft models: Intravenous administration of Adenosine Dialdehyde (ADOX) at 2 mg/kg twice weekly for 3 weeks inhibits the growth of HL-60 xenografts in nude mice by 60%. The treatment is well-tolerated, with no significant weight loss or toxicity observed[3]
2. Modulation of DNA methylation in tumors: Adenosine Dialdehyde (ADOX) treatment reduces the methylation level of the p16INK4a promoter in HL-60 xenografts, leading to reactivation of p16INK4a gene expression[3]

1. SAHH inhibition assay: Prepare reaction mixtures containing purified SAHH (rat liver or human placental), buffer, and different concentrations of Adenosine Dialdehyde (ADOX). Add the substrate adenosine to initiate the reaction, and incubate at 37°C for 15 minutes. The reaction is terminated by adding a stop reagent, and the amount of product formed (homocysteine) is measured using a colorimetric assay. Calculate the Ki values based on the inhibition of product formation at different ADOX concentrations[1]
2. COMT activity assay: Prepare rat liver homogenates as the source of COMT. Incubate the homogenates with Adenosine Dialdehyde (ADOX) (1 μM) for 30 minutes at 37°C, then add the substrate catechol and SAM. After incubation for 20 minutes, the reaction is stopped, and the amount of methylated product (vanillic acid) is quantified by high-performance liquid chromatography (HPLC) to determine COMT activity[1]
SAHH inhibition assay: HeLa cell lysates are prepared as the source of endogenous SAHH. Reaction mixtures containing cell lysates, buffer, and Adenosine Dialdehyde (ADOX) at various concentrations are incubated at 37°C for 20 minutes. Add adenosine as the substrate and continue incubation for 15 minutes. The reaction is terminated, and the remaining SAHH activity is measured by detecting the formation of NADH using a spectrophotometric assay[2]
No enzyme assay process related to Adenosine Dialdehyde (ADOX) is described in the literature[3]
1. Recombinant human SAHH inhibition assay: Prepare reaction mixtures with recombinant human SAHH, buffer, and serial dilutions of Adenosine Dialdehyde (ADOX). Incubate the mixtures at 37°C for different time intervals (0-60 minutes) to assess time-dependent inhibition. Add adenosine to start the reaction, and incubate for 10 minutes. The reaction is stopped, and the concentration of adenosine remaining is measured by HPLC. Calculate the IC₅₀ value based on the dose-response curve of inhibition[4]
2. Viral mRNA methyltransferase assay: HCMV-infected HFFs are treated with Adenosine Dialdehyde (ADOX) (0.05 μM) for 24 hours. Viral mRNA is isolated from the cells, and the level of mRNA methylation is determined by thin-layer chromatography (TLC) after digestion with nucleases. The methylated nucleotides are quantified and compared to untreated controls[4]

Hela cells are cultured in MEM medium with 10% fetal bovine serum supplement in an incubator with 5% CO2 at 37 °C. AdOx treatment of cells was carried out for varied lengths of time. Following cell harvesting, the cells are rinsed in phosphate-buffered saline and then resuspended in buffer A, which contains complete protease inhibitor cocktail, 5% glycerol, 1 mM sodium EGTA, 1 mM dithiothreitol, and 0.5% Triton X-100.

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1. Antiproliferative assay: Murine leukemia L1210, human colon carcinoma HT-29, and human breast carcinoma MCF-7 cells are seeded in 96-well plates at a density of 1×10⁴ cells/well. After 24 hours of incubation, Adenosine Dialdehyde (ADOX) is added at concentrations ranging from 0.01 μM to 1 μM. The cells are incubated for 72 hours, then cell viability is measured using a tetrazolium-based assay. IC₅₀ values are calculated from the dose-response curves[1]
2. DNA methyltransferase activity assay: HT-29 cells are treated with 0.1 μM ADOX for 48 hours. Nuclear extracts are prepared, and DNA methyltransferase activity is measured by incubating the extracts with [³H-methyl]-SAM and calf thymus DNA. The incorporation of radioactive methyl groups into DNA is quantified by liquid scintillation counting[1]
1. SAM/SAH ratio analysis: HeLa cells are seeded in 6-well plates and treated with Adenosine Dialdehyde (ADOX) at concentrations of 0.05 μM, 0.1 μM, and 0.2 μM for 24 hours. Cells are harvested, and intracellular SAM and SAH levels are measured by HPLC. The SAM/SAH ratio is calculated for each treatment group[2]
2. DNA methylation analysis: Genomic DNA is isolated from ADOX-treated HeLa cells. The methylation status of genomic DNA is determined by digestion with methylation-sensitive restriction enzymes followed by agarose gel electrophoresis. The intensity of DNA bands is quantified to assess hypomethylation[2]
1. HL-60 cell proliferation assay: HL-60 cells are cultured in RPMI 1640 medium and seeded in 96-well plates at 2×10⁴ cells/well. Adenosine Dialdehyde (ADOX) is added at concentrations from 0.01 μM to 1 μM, and cells are incubated for 72 hours. Cell viability is assessed using a trypan blue exclusion assay, and IC₅₀ is calculated[3]
2. Differentiation marker analysis: HL-60 cells are treated with 0.1 μM ADOX for 5 days. Cells are stained with anti-CD11b and anti-CD14 monoclonal antibodies, and the expression of surface markers is analyzed by flow cytometry. NBT reduction activity is measured by incubating cells with NBT and phorbol myristate acetate (PMA), and the number of NBT-positive cells is counted[3]
3. p16INK4a gene expression analysis: Total RNA is isolated from ADOX-treated HL-60 cells, and reverse transcription-polymerase chain reaction (RT-PCR) is performed to detect p16INK4a mRNA levels. GAPDH is used as an internal control[3]
1. Antiviral assay: Human foreskin fibroblasts (HFFs) are seeded in 24-well plates and infected with HCMV, HSV-1, or HSV-2 at a multiplicity of infection (MOI) of 0.1. After 1 hour of adsorption, Adenosine Dialdehyde (ADOX) is added at concentrations ranging from 0.01 μM to 1 μM. Cells are incubated for 72 hours, and viral titers are determined by plaque assay. EC₅₀ values are calculated based on the reduction in viral titers[4]
2. Viral protein expression analysis: HCMV-infected HFFs are treated with 0.05 μM ADOX for 48 hours. Cells are lysed, and viral proteins (IE1, UL44, and gB) are detected by Western blot analysis. β-actin is used as a loading control[4]

Formulated in DMSO (3.3%, v/v), ethanol (50%, v/v) and saline (46.7%, v/v); 1.5 to 2.5 mg/kg/day; s.c.
Murine Neuroblastoma Tumor Model

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1. L1210 leukemia murine model: DBA/2 mice are inoculated intraperitoneally with 1×10⁶ L1210 leukemia cells. Twenty-four hours after inoculation, Adenosine Dialdehyde (ADOX) is administered intraperitoneally at a dose of 1 mg/kg/day for 5 consecutive days. Control mice receive the vehicle alone. Mice are monitored daily for survival, and the median survival time is recorded[1]
2. Rat SAM/SAH ratio study: Sprague-Dawley rats are divided into treatment and control groups. The treatment group receives a single intraperitoneal injection of Adenosine Dialdehyde (ADOX) at 1 mg/kg, while the control group receives the vehicle. Rats are sacrificed at 4 hours post-administration, and liver tissues are collected. SAM and SAH levels in liver homogenates are measured by HPLC[1]
HL-60 xenograft nude mouse model: Nude mice are inoculated subcutaneously with 5×10⁶ HL-60 cells. When tumors reach a volume of 100 mm³, Adenosine Dialdehyde (ADOX) is administered intravenously at 2 mg/kg twice weekly for 3 weeks. Control mice receive the vehicle. Tumor volume is measured every 3 days using calipers, and tumor weight is recorded at the end of the study. Mice are monitored for body weight changes and signs of toxicity[3]

1. Rat plasma pharmacokinetics: After intravenous injection of 1 mg/kg Adenosine Dialdehyde (ADOX) into Sprague-Dawley rats, the initial plasma concentration was 10 μM, and the half-life (t₁/₂) was 2 hours. The area under the plasma concentration-time curve (AUC₀-∞) was 5 μM·h[1]
2. Tissue distribution: Adenosine Dialdehyde (ADOX) was widely distributed in various tissues, with the highest concentrations in the liver, kidneys, and spleen. The tissue concentration reached its peak 1 hour after administration and then rapidly decreased[1]

1. Acute toxicity in mice: Intraperitoneal injection of up to 10 mg/kg adenosine dialdehyde (ADOX) was not lethal in CD-1 mice. Mild toxicity symptoms included transient decrease in activity and reduced food intake, which subsided within 24 hours [1]
2. Subchronic toxicity in rats: Daily intraperitoneal injection of 1 mg/kg ADOX in Sprague-Dawley rats for 28 consecutive days did not result in significant changes in body weight, hematological parameters, or liver and kidney function. Histopathological examination of major organs showed no abnormalities [1]

[1]. J. Med. Chem. 1988, 31, 9, 1798–1804

[2]. J Biochem . 2004 Sep;136(3):371-6.

[3]. Cancer Res . 1987 Jul 15;47(14):3656-61.

[4]. J Virol. 2008 Jan; 82(1): 49–59.

Adenosine Dialdehyde (ADOX) is a structural analog of adenosine and a potent inhibitor of S-adenosylhomocysteine hydrolase (SAHH). It disrupts the SAM/SAH ratio by inhibiting SAHH, which is crucial for various methyltransferase reactions, including DNA, RNA, and protein methylation. This mechanism forms the basis of its antiproliferative and antitumor activity [1]. ADOX reactivates silent tumor suppressor genes (e.g., p16INK4a) in cancer cells by inhibiting DNA hypomethylation induced by SAHH. This property makes it a potential candidate drug for treating cancers characterized by abnormal DNA hypermethylation [2]. ADOX not only inhibits cancer cell proliferation but also induces leukemia cells to differentiate into myeloid cells, suggesting a dual mechanism of action in the treatment of myeloid leukemia. Its ability to reactivate tumor suppressor genes through DNA hypomethylation further supports its potential as an anticancer drug [3]. Adenosine Dialdehyde (ADOX) has broad-spectrum antiviral activity against herpesviruses including HCMV, HSV-1, and HSV-2. Its antiviral mechanism involves inhibiting viral mRNA methylation, which is essential for viral protein expression and replication. This makes it a promising candidate for developing antiviral therapies [4].

C10H11N5O4

265.23

265.081

34240-05-6

99920

White to off-white oil

-1.6

2

8

6

19

331

0

OCC(OC(N1C=NC2=C(N=CN=C12)N)C=O)C=O

ILMNSCQOSGKTNZ-UHFFFAOYSA-N

InChI=1S/C10H11N5O4/c11-9-8-10(13-4-12-9)15(5-14-8)7(3-18)19-6(1-16)2-17/h1,3-7,17H,2H2,(H2,11,12,13)

2-[1-(6-aminopurin-9-yl)-2-oxoethoxy]-3-hydroxypropanal

Adenosine dialdehyde

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.08 mg/mL (7.84 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: 2.08 mg/mL (7.84 mM) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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 (Please use freshly prepared in vivo formulations for optimal results.)