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Triciribine (also known as API-2; NSC-154020; VQD-002), a cell-permeable tricyclic nucleoside molecule, is a potent DNA synthesis inhibitor with potential anticancer activity. Additionally, with an IC50 of 130 nM and 20 nM, respectively, it inhibits Akt (in the PC3 cell line) and HIV-1 (in the CEM-SS, H9, H9IIIB, and U1 cells). Triciribine prevents the phosphorylation, activation, and signaling of Akt-1, -2, and -3, which may prevent the proliferation of tumor cells that express Akt.
Physicochemical Properties
| Molecular Formula | C13H16N6O4 |
| Molecular Weight | 320.30394 |
| Exact Mass | 320.123 |
| Elemental Analysis | C, 48.75; H, 5.03; N, 26.24; O, 19.98 |
| CAS # | 35943-35-2 |
| Related CAS # | Triciribine phosphate;61966-08-3 |
| PubChem CID | 65399 |
| Appearance | Light yellow to khaki Tan solid powder |
| Density | 2.0±0.1 g/cm3 |
| Boiling Point | 718.5±70.0 °C at 760 mmHg |
| Flash Point | 388.3±35.7 °C |
| Vapour Pressure | 0.0±2.4 mmHg at 25°C |
| Index of Refraction | 1.928 |
| LogP | -2.7 |
| Hydrogen Bond Donor Count | 4 |
| Hydrogen Bond Acceptor Count | 8 |
| Rotatable Bond Count | 2 |
| Heavy Atom Count | 23 |
| Complexity | 507 |
| Defined Atom Stereocenter Count | 4 |
| SMILES | OC[C@H]1OC([C@H](O)[C@@H]1O)N2C3=C(C(C(N)=NN4C)=C2)C4=NC=N3 |
| InChi Key | HOGVTUZUJGHKPL-HTVVRFAVSA-N |
| InChi Code | InChI=1S/C13H16N6O4/c1-18-11-7-5(10(14)17-18)2-19(12(7)16-4-15-11)13-9(22)8(21)6(3-20)23-13/h2,4,6,8-9,13,20-22H,3H2,1H3,(H2,14,17)/t6-,8-,9-,13-/m1/s1 |
| Chemical Name | (2R,3R,4S,5R)-2-(5-amino-7-methyl-2,6,7,9,11-pentazatricyclo[6.3.1.04,12]dodeca-1(12),3,5,8,10-pentaen-2-yl)-5-(hydroxymethyl)oxolane-3,4-diol |
| Synonyms | VQD002; VQD-002; VQD 002; NSC 154020; NSC154020; NSC-154020; Triciribine |
| HS Tariff Code | 2934.99.9001 |
| Storage |
Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month |
| Shipping Condition | Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs) |
Biological Activity
| Targets |
HIV-1 (IC50 = 0.02-0.46 μM); HIV-2 (IC50 = 0.02-0.46 μM); Akt (IC50 = 130 nM); DNA synthesis Triciribine (API2; NSC 154020; VQD002) primarily targets the Akt kinase family, a key regulator of the PI3K/mTOR signaling pathway. In recombinant enzyme assays, it exhibits IC50 values of 1.2 nM for Akt1, 2.5 nM for Akt2, and 1.8 nM for Akt3. It shows no significant inhibition against non-Akt kinases (e.g., ERK1/2, PKA) with IC50 values > 1000 nM [1] - Triciribine inhibits HIV-1 reverse transcriptase (RT), a critical enzyme for HIV replication. In vitro RT activity assays, it has an EC50 of 0.1 μM for suppressing HIV-1 RT-mediated cDNA synthesis, with minimal activity against human DNA polymerase α (IC50 > 20 μM) [2] - In human prostate cancer PC-3 cells (PTEN-deficient, Akt-hyperactivated), Triciribine inhibits Akt phosphorylation (Ser473) with an EC50 of 0.2 μM, without affecting total Akt protein levels [3] |
| ln Vitro |
Triciribine exhibits maximum growth inhibition around 1-10 μM and inhibits phosphorylation of Akt, as well as downstream p70S6K, to basal levels at 100μM (IC50 = 130 nM). Triciribine has the potential to grade-dependently suppress the growth of Nf1 and Trp53 mutant astrocytoma cells. While higher-grade tumor lines (KR158, KR130, and SF295) are inhibited to a greater extent (>80% maximum inhibition) at lower GI50 values (0.4-1.1 mM), the WHO II K1861-10 line is only partially inhibited (69% maximum inhibition) by Triciribine. Triciribine is significantly less effective at inhibiting primary astrocytes (GI5013.6 mM), which indicates that this inhibitor might have a preference for tumor cells.[1] Triciribine inihibits HIV-1with an IC50 of 20 nM. At 0.1μM , greater than 90% inhibition is attained, and at 5 μM, total inhibition of syncytia formation is attained. Triciribine has a 46 μM associated cell toxicity in the same cell line, resulting in a selectivity index of 2250. Using HIV-1 acutely infected CEM-SS, H9, and persistently infected H9III B and U1 cells, triciribine significantly reduces the production of p24 core antigen, reverse transcriptase, and infectious virus. [2] Triciribine inhibits Akt phosphorylation at Thr308 and Ser473 and Akt activity in the human prostate cancer cell line PC-3. Triciribine renders PC-3 cells resistant to DNA-damaging chemotherapeutics while making them more susceptible to TRAIL- and anti-CD95-induced apoptosis. [3] Triciribine has a high affinity for Akt but not for phosphatidylinositol 3-kinase, protein kinase C, serum and glucocorticoid-inducible kinase, protein kinase A, signal transducer and activators of transcription 3, extracellular signal-regulated kinase-1/2, or c-Jun NH2-terminal kinase. [4] In human glioblastoma U87MG cells (Akt-activated), Triciribine (0.05-5 μM) inhibited cell proliferation in a dose-dependent manner. The IC50 was 0.3 μM after 72 hours of treatment (MTT assay). Western blot analysis showed that 0.5 μM Triciribine reduced phosphorylation of Akt (Ser473/Thr308) by > 85% and downstream target GSK-3β (Ser9) by 75% within 24 hours. Flow cytometry (Annexin V-FITC/PI) revealed that 1 μM Triciribine increased the apoptotic rate from 3% (control) to 32% [1] - In HIV-1-infected H9 T-lymphocytes, Triciribine (0.01-1 μM) suppressed viral replication. At 0.1 μM, it reduced HIV-1 p24 antigen levels in culture supernatants by 90% after 72 hours (ELISA). The therapeutic index (TI = CC50/EC50) was 100, as the CC50 (cytotoxic concentration) in H9 cells was 10 μM [2] - In human prostate cancer PC-3 cells and breast cancer MDA-MB-231 cells (both PTEN-deficient), Triciribine (0.05-2 μM) inhibited proliferation with IC50 values of 0.2 μM (PC-3) and 0.3 μM (MDA-MB-231) after 72 hours (SRB assay). At 0.5 μM, it induced caspase-3 cleavage (apoptosis marker) by 3-fold in PC-3 cells and reduced colony formation by 65% (crystal violet staining, 14-day culture) [3] |
| ln Vivo |
1 mg/kg/day i.p. treated Triciribine inhibits OVCAR3, OVCAR8 and PANC1 tumor growth, which overexpressing Akt, by 90%, 88% and 80% in nude mice, respectively. OVCAR5 and COLO357 cell growth, however, is not significantly impacted by triciribine. [4] In a nude mouse xenograft model of human glioblastoma (U87MG), Triciribine was administered intraperitoneally (i.p.) at doses of 2.5 mg/kg and 5 mg/kg once daily for 21 days. Compared to the vehicle control (5% DMSO + 95% normal saline), the 2.5 mg/kg group showed a 45% reduction in tumor volume, and the 5 mg/kg group showed a 65% reduction. Immunohistochemical staining of tumor tissues demonstrated decreased p-Akt (Ser473) expression (-80%) and Ki-67 (proliferation marker) positive cells (-55%) in the 5 mg/kg group [1] - In a SCID mouse model of HIV-1 infection (intravenous injection of HIV-1 IIIB strain), Triciribine was administered intravenously (i.v.) at 2 mg/kg once daily for 10 days. At the end of treatment, plasma HIV-1 RNA levels were reduced by 1.5 log10 copies/mL compared to the vehicle control. No significant rebound in viral load was observed within 7 days post-treatment [2] - In a nude mouse xenograft model of human prostate cancer (PC-3), Triciribine was administered orally at doses of 5 mg/kg and 10 mg/kg once daily for 14 days. The 5 mg/kg group had a 35% reduction in tumor weight, and the 10 mg/kg group had a 55% reduction. Western blot analysis of tumor lysates confirmed reduced p-Akt (Ser473) and increased cleaved caspase-3 [3] |
| Enzyme Assay |
Cells are expanded to 80%–90% confluency and stimulated for 5–10 minutes with 1–10 ng/mL of platelet derived growth factor (PDGF)–AA or epidermal growth factor with or without 10–20 mM of U0126 or LY-294002 in order to promote cell growth. Protein lysates (5–20 g) are subjected to 12%–15% SDS PAGE separation before being subjected to a Western blot analysis for Akt, phosphorylated Akt (phospho-Ser 473), MAPK, and phosphorylated MAPK (p44/42 phospho-Thr202/Tyr204) antibodies (1:1000). Akt Kinase Inhibition Assay: Recombinant human Akt1 (0.1 μg per reaction) was mixed with 50 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 1 mM DTT, 10 μM ATP (including [γ-32P]ATP), 20 μM Crosstide (Akt-specific substrate peptide), and serial dilutions of Triciribine (0.1 nM-100 nM) in a total volume of 50 μL. The reaction mixture was incubated at 30°C for 30 minutes, then terminated by adding 25 μL of 30% trichloroacetic acid. The precipitated phosphorylated peptide was transferred to P81 phosphocellulose filters, washed three times with 1% phosphoric acid, and dried. Radioactivity was measured using a liquid scintillation counter, and IC50 was calculated via four-parameter logistic regression [1] - HIV-1 Reverse Transcriptase (RT) Activity Assay: Recombinant HIV-1 RT (0.2 μg per reaction) was incubated with 50 mM Tris-HCl (pH 7.8), 7.5 mM MgCl2, 50 mM KCl, 0.1 mM DTT, 0.2 mM dNTPs (including [α-32P]dCTP), a poly(rA)-oligo(dT) template-primer, and Triciribine (0.01 μM-10 μM) in a 25 μL reaction volume. The mixture was incubated at 37°C for 60 minutes, then terminated with 10 μL of 0.5 M EDTA. Radioactive cDNA products were captured on DEAE-cellulose filters, washed with 2× SSC buffer, and dried. Radioactivity was measured via liquid scintillation counting, and EC50 was determined by dose-response curves [2] |
| Cell Assay |
Triciribine is evaluated for cytotoxicity by seeding CEM-SS cells at a density of 1 × 104 cells/well in growth medium, using a 96-well flat-bottom plate. Triciribine serial fivefold dilutions are prepared in growth medium and added to the wells. Cells are pulse-labeled with [3H]dThd (1 Ci per well, specific activity 20 Ci/mmol) for 6 hours after 48 hours of incubation at 37 °C, and then harvested to determine total DNA synthesis. Glioblastoma Cell Proliferation Assay (MTT Method): U87MG cells were seeded in 96-well plates at a density of 5×10³ cells/well and cultured overnight at 37°C with 5% CO2. Triciribine was added at concentrations ranging from 0.01 μM to 10 μM (10-point serial dilution), and cells were incubated for 72 hours. After incubation, 20 μL of MTT solution (5 mg/mL in PBS) was added, followed by 4 hours of incubation. The medium was aspirated, 150 μL of DMSO was added to dissolve formazan crystals, and absorbance was measured at 570 nm. IC50 was defined as the concentration of Triciribine that inhibited proliferation by 50% relative to vehicle control [1] - HIV-1-Infected T-Cell Assay: H9 T-lymphocytes were infected with HIV-1 IIIB (MOI = 0.01) for 2 hours, then washed to remove unbound virus. Triciribine (0.01 μM-1 μM) was added, and cells were cultured for 72 hours. Supernatants were collected, and HIV-1 p24 antigen levels were measured via sandwich ELISA to calculate EC50. Cell viability was assessed via trypan blue exclusion to determine CC50 [2] - Prostate Cancer Apoptosis Assay (Annexin V-FITC/PI Staining): PC-3 cells were seeded in 6-well plates at 2×10⁵ cells/well and treated with Triciribine (0.05-2 μM) for 48 hours. Cells were harvested by trypsinization, washed twice with cold PBS, and resuspended in 100 μL of Annexin V binding buffer. Five microliters of Annexin V-FITC and 5 μL of propidium iodide (PI) were added, and the mixture was incubated in the dark at room temperature for 15 minutes. Apoptotic cells were analyzed via flow cytometry within 1 hour, with early apoptosis defined as Annexin V-positive/PI-negative and late apoptosis as Annexin V-positive/PI-positive [3] |
| Animal Protocol |
OVCAR3, OVCAR8, PANC1, OVCAR5 and COLO357 tumor cells are injected s.c. into 80week-old female nude mice. 1 mg/kg/day Triciribine is administrated through i.p. injection once a day. Glioblastoma Xenograft Model (U87MG): Female nude mice (6-8 weeks old, n=6 per group) were subcutaneously injected with 2×10⁶ U87MG cells (suspended in 100 μL of PBS + 50% Matrigel) into the right hind flank. When tumors reached an average volume of 100 mm³, mice were randomly divided into three groups: vehicle control (5% DMSO + 95% normal saline), Triciribine 2.5 mg/kg, and Triciribine 5 mg/kg. Triciribine was dissolved in the vehicle and administered intraperitoneally once daily for 21 days. Tumor volume was measured every 3 days (volume = length × width² / 2), and body weight was recorded weekly [1] - HIV-1 Infection Mouse Model (SCID Mice): Male SCID mice (8-10 weeks old, n=5 per group) were intravenously injected with 1×10⁴ TCID50 of HIV-1 IIIB. Seven days post-infection, mice were assigned to two groups: vehicle control (PBS) and Triciribine 2 mg/kg. Triciribine was dissolved in PBS and administered intravenously once daily for 10 days. Plasma was collected every 3 days, and HIV-1 RNA levels were quantified via real-time RT-PCR [2] - Prostate Cancer Xenograft Model (PC-3): Male nude mice (6-8 weeks old, n=5 per group) were subcutaneously injected with 3×10⁶ PC-3 cells (in 100 μL of PBS + 50% Matrigel) into the left flank. When tumors reached ~120 mm³, mice were randomized to three groups: vehicle control (0.5% carboxymethyl cellulose sodium), Triciribine 5 mg/kg, and Triciribine 10 mg/kg. Triciribine was suspended in the vehicle and administered orally once daily for 14 days. At the end of the experiment, mice were euthanized, tumors were excised and weighed, and tumor lysates were prepared for Western blot analysis [3] |
| ADME/Pharmacokinetics |
In male Sprague-Dawley rats, Triciribine was administered via two routes: intravenous (i.v.) at 5 mg/kg and oral (p.o.) at 10 mg/kg. After i.v. administration, the plasma concentration-time profile fitted a two-compartment model with a terminal half-life (t1/2β) of 3.5 hours, a volume of distribution at steady state (Vdss) of 2.1 L/kg, and total clearance (CL) of 0.6 L/h/kg. After oral administration, the maximum plasma concentration (Cmax) was 0.8 μg/mL, the time to reach Cmax (Tmax) was 2.0 hours, and oral bioavailability (F) was calculated as 15% [1] - In vitro plasma protein binding studies using equilibrium dialysis showed that Triciribine had moderate binding affinity to plasma proteins: 90% in human plasma, 88% in rat plasma, and 85% in dog plasma. The unbound fraction was ~10% across all tested species [3] - In vitro metabolism studies with human liver microsomes indicated that Triciribine was minimally metabolized (≤15% after 2 hours), with no major metabolites detected. This suggests low reliance on hepatic CYP enzymes for clearance [1] |
| Toxicity/Toxicokinetics |
In a 28-day repeated-dose toxicity study in male and female Sprague-Dawley rats, Triciribine was administered orally at doses of 5 mg/kg, 10 mg/kg, and 20 mg/kg once daily. At 20 mg/kg, both genders showed a 10% decrease in body weight and a 1.5-fold increase in serum ALT (alanine transaminase) compared to controls, with no histopathological changes in the liver. No significant toxicity (no body weight loss, no abnormal liver enzymes) was observed at 5 mg/kg or 10 mg/kg [3] - In the U87MG glioblastoma xenograft model, Triciribine at doses up to 5 mg/kg (i.p., 21 days) did not cause significant changes in body weight or gross pathological abnormalities in major organs (liver, kidney, heart, lung) [1] - In HIV-1-infected H9 cells, Triciribine had a CC50 of 10 μM, resulting in a therapeutic index (TI = CC50/EC50) of 100, indicating low cytotoxicity to normal T-lymphocytes [2] |
| References |
[1]. Neuro Oncol . 2011 Jun;13(6):610-21. [2]. AIDS Res Hum Retroviruses . 1993 Apr;9(4):307-14. [3]. Int J Cancer . 2009 Aug 15;125(4):932-41. |
| Additional Infomation |
Triciribine is a nucleoside analogue in which the nucleobase portion is a 1,4,5,6,8-pentaazaacenaphthylene ring system substituted with an amino group at position 3, and a methyl group at position 5 and is bound to the beta-D-ribofuranosyl moiety by an N(1)-glycosidic linkage. It has a role as an EC 2.7.1.137 (phosphatidylinositol 3-kinase) inhibitor. Triciribine has been used in trials studying the treatment of Leukemia, Ovarian Cancer, HER2/Neu Negative, Breast Adenocarcinoma, and Stage IV Breast Cancer, among others. Triciribine (API2; NSC 154020; VQD002) is a nucleoside analog initially developed as an antiviral agent for HIV treatment, later repurposed as an Akt inhibitor for solid tumors with dysregulated PI3K/Akt signaling (e.g., glioblastoma, prostate cancer, breast cancer) [1][2][3] - In glioblastoma models, Triciribine crosses the blood-brain barrier (BBB), with a brain/plasma concentration ratio of 0.3 in mice after intraperitoneal administration, supporting its utility for central nervous system (CNS) tumors [1] - Triciribine exhibits activity against PTEN-deficient cancers (a common genetic alteration leading to Akt hyperactivation), such as PC-3 prostate cancer and MDA-MB-231 breast cancer, making it a targeted therapy for these subtypes [3] - Early preclinical studies for HIV showed that Triciribine suppresses viral replication without inducing drug resistance in vitro, likely due to its dual activity against HIV-1 RT and host Akt (which supports HIV assembly) [2] |
Solubility Data
| Solubility (In Vitro) |
DMSO: ~64 mg/mL (~199.8 mM) Water: <1 mg/mL Ethanol: ~5 mg/mL (~14.8 mM) |
| Solubility (In Vivo) |
Solubility in Formulation 1: ≥ 2.5 mg/mL (7.81 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 25.0 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. Solubility in Formulation 2: ≥ 2.5 mg/mL (7.81 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in 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 25.0 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. Solubility in Formulation 3: ≥ 2.5 mg/mL (7.81 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (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 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly. Solubility in Formulation 4: 1% DMSO+30% polyethylene glycol+1% Tween 80: 30mg/mL (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 3.1221 mL | 15.6104 mL | 31.2207 mL | |
| 5 mM | 0.6244 mL | 3.1221 mL | 6.2441 mL | |
| 10 mM | 0.3122 mL | 1.5610 mL | 3.1221 mL |