69655-05-6

Usage

Uses

1. Used in Antiviral Applications:
Dideoxyinosine is used as an antiviral agent for the treatment of HIV and related lymphoma. It is most effective in combination therapy, acting as a reverse transcriptase inhibitor and potent anti-retroviral agent.
2. Used in HIV Treatment:
Dideoxyinosine is used as an oral medication for adult and pediatric patients with advanced HIV infection who are either intolerant or have significantly deteriorated on zidovudine. It helps increase CD4 cell counts and decrease p24 antigen levels.
3. Used in Drug Delivery Systems:
Dideoxyinosine can be given orally in the form of buffered chewable tablets or as a solution prepared from the powder. Both oral dosage forms are buffered to prevent acidic decomposition of ddI to hypoxanthine in the stomach.
4. Used in Combination Therapy:
Dideoxyinosine is used in combination with AZT (zidovudine) to inhibit HIV replication in vitro. It is effective against some AZT-resistant strains of HIV and causes less myelosuppression than AZT.
5. Used in the Treatment of Advanced HIV Infection:
Dideoxyinosine is recommended for the treatment of patients with advanced HIV infection who have received prolonged treatment with AZT but have become intolerant to, or experienced immunosuppression from, the drug.
6. Used in the Management of Major Adverse Effects:
Dideoxyinosine exhibits fewer major dose-limiting toxicities, such as painful peripheral neuropathy and pancreatitis, compared to other antiviral drugs like AZT. It also shows insignificant bone marrow suppression, making it a preferred choice for patients with advanced HIV infection.

Originator

National Cancer Institute(NIH) (U.S.A.)

Indications

Didanosine (ddI, Videx) is an adenosine analogue with activity against HIV-1, HIV-2, and HTLV-I. It is approved as part of a multidrug regimen for the therapy of HIV infection and is also used as postexposure HIV prophylaxis

Manufacturing Process

In a 500 ml flask with a shoulder was separately charged 50 ml of medium (pH 7.0) containing 0.5 g/dl of yeast extract, 1.0 g/dl of peptone, 1.0 g/dl of meat extract and 0.5 g/dl of NaCl followed by sterilization. One platinum loop of each microorganism shown in Table which had been preincubated in bouillon agar medium at 30°C for 16 hours was inoculated on the medium followed by shake culture at 30°C for 16 hours. After the cells were isolated from the obtained culture solution by centrifugal separation, the cells were washed with 0.05 M Tris-HCl buffer (pH 7.2) and further centrifuged to give washed cells.The washed cells described above were added to 0.05 M Tris-HCl buffer (pH 7.2) containing 1 g/dl of 2',3'-dideoxyadenosine in a concentration of 5 g/dl followed by reacting at 30°C for 2 hours. The amount of 2',3'-dideoxyinosine produced at this stage is shown in the next Table.This way 2',3'-dideoxyinosine may be produced from 2',3'-dideoxyadenosine in a short period of time, by contacting microorganisms supplied at low cost, products containing the same or treated products thereof, with a substrate.

Therapeutic Function

Antiviral

Antimicrobial activity

Didanosine is active against HIV-1, HIV-2 and HTLV-1.

Acquired resistance

Codon changes at positions 65 or 74 in HIV reverse transcriptase are associated with reduced susceptibility.

Air & Water Reactions

Water soluble.

Fire Hazard

Flash point data for Dideoxyinosine are not available; however, Dideoxyinosine is probably combustible.

Pharmaceutical Applications

An analog of deoxyadenosine, formulated for oral administration.

Mechanism of action

Didanosine (ddl) is a purine dideoxynucleoside, which is an analogue of inosine. Chemically, it is 2′,3′-dideoxyinosine, and it differs from inosine by having hydrogen atoms in place of the 2′- and 3′-hydroxyl groups on the ribose ring. Didanosine is a pro-drug that is bioactivated by metabolism to dideoxyadenosine triphosphate, which is a competitive inhibitor of viral RT and is incorporated into the developing viral DNA in place of deoxyladenosine triphosphate. As such, this agent causes chain termination because of the absence of a 3′-hydroxyl group. Didanosine inhibits HIV RT and exerts a virustatic effect on the retroviruses. Combined with ZDV, antiretroviral activity of ddI is increased.

Pharmacokinetics

Oral absorption: c. 40% Cmax 400 mg once daily: 0.93 mg/L Plasma half-life: c. 1.4 h Volume of distribution: c. 1 L/kg Plasma protein binding: <5% Absorption Bioavailability is reduced by about half when taken with food and the drug should be given at least 30 min before a meal. The peak plasma concentration achieved by enteric-coated tablets is less than half that of buffered tablets. Distribution Central nervous system (CNS) penetration is relatively poor. Median concentrations in semen (455 ng/mL; range < 50–2190 ng/mL) are greater than those in blood (<50 ng/mL; range <50–860 ng/mL). It is secreted in breast milk. Metabolism Based upon animal studies it is presumed that metabolism occurs by the pathways responsible for the elimination of endogenous purines by xanthine oxidase. Metabolism may be altered in patients with severe hepatic impairment; however, no specific dose adjustment is recommended. Excretion Renal clearance by glomerular filtration and active tubular secretion accounts for 50% of total body clearance. Urinary recovery accounts for about 20% of the oral dose in adults. The half-life increases three-fold in patients requiring dialysis. Patients with a creatinine clearance <60 mL/min may be at greater risk of toxicity.

Clinical Use

The most common adverse effect produced by didanosine is diarrhea.Abdominal pain, nausea, vomiting, anorexia, and dose-related peripheral neuropathy may occur. Pancreatitis occurs rarely, as do hyperuricemia, bone marrow suppression, retinal depigmentation, and optical neuritis. Resistance to didanosine appears to result from mutations different from those responsible for zidovudine resistance.

Side effects

Most serious are pancreatitis (fatal and non-fatal), lactic acidosis and severe hepatomegaly with steatosis (fatal and nonfatal), retinopathy, optic neuritis and dose-related peripheral neuropathy. Patients with low body weight may require dose modification. A strong association with non-cirrhotic portal hypertension has been described. The combination with stavudine should be avoided in pregnant women as fatal cases of lactic acidosis have been reported. Caution should also be exercised in patients with known risk factors for liver disease. Therapy should be stopped in patients who develop clinical or laboratory evidence of lactic acidosis or hepatotoxicity. Monitoring lactate levels prospectively is not recommended as mild hyperlactatemia occurs in asymptomatic patients and has a poor positive predictive value for the development of lactic acidosis. Caution should be exercised in co-administering other drugs with known neurotoxicity and in patients with a history of neuropathy. Treatment should stop if symptoms and signs of neuropathy are observed, but the condition is usually reversible and patients with resolved neuropathy may be retreated at a reduced dosage. Retinal depigmentation has been observed in children and twice-yearly dilated retinal examination is recommended.

Drug interactions

Potentially hazardous interactions with other drugsAllopurinol: concentration of didanosine increased - avoid.Antibacterials: ciprofloxacin, tetracyclines, and other antibiotics affected by indigestion remedies - do not administer within 2 hours of didanosine.Antivirals: absorption of atazanavir reduced (give at least 2 hours before or 1 hour after didanosine tablets); manufacturer of darunavir advises to take didanosine 1 hour before or 2 hours after darunavir; didanosine tablets reduce absorption of indinavir (give at least 1 hour apart); concentration possibly increased by ganciclovir, valganciclovir and tenofovir - avoid with tenofovir; give didanosine and ritonavir at least 2.5 hours apart; increased risk of side effects with ribavirin and stavudine - avoid; concentration reduced by tipranavir (give tipranavir and didanosine capsules at least 2 hours apart); give didanosine 2 hours before or 4 hours after rilpivirine.Cytotoxics: increased risk of toxicity with hydroxycarbamide - avoid. Orlistat: absorption of didanosine possibly reduced.

Metabolism

Didanosine is less toxic than ZDV. The CSF fluid/plasma ratio of ddI is 0.2. Didanosine is ultimately converted to hypoxanthine, xanthine, and uric acid through the usual metabolic pathway for purines. The latter is a nontoxic metabolic product. Didanosine is given in advanced HIV infection, ZDV intolerance, or significant clinical/immunologic deterioration.

Precautions

Buffering agents that are compounded with didanosineto counteract its degradation by gastric acid mayinterfere with the absorption of other drugs that requireacidity (e.g., indinavir, delavirdine, ketoconazole, fluoroquinolones,tetracyclines, dapsone). An enteric-coatedformulation (Videx EC) that dissolves in the basic pH ofthe small intestine is not susceptible to these interactions.Ganciclovir and valganciclovir can increase bloodlevels of didanosine.The use of zalcitabine with didanosineis not recommended because that combination carriesan additive risk of peripheral neuropathy.The combinationof didanosine with stavudine increases the riskof pancreatitis, hepatotoxicity, and peripheral neuropa-thy. Stavudine should not be given with didanosine topregnant women because of the increased risk of metabolicacidosis.

InChI:InChI=1/C10H12N4O3/c15-3-6-1-2-7(17-6)14-5-13-8-9(14)11-4-12-10(8)16/h4-7,15H,1-3H2,(H,11,12,16)

Upstream product

• 42867-68-5 2',3'-didehydro-2',3'-dideoxyinosine 
• 4097-22-7 [(S)-5-(6-Amino-purin-9-yl)-tetrahydro-furan-2-yl]-methanol 
• 141684-85-7 9-<5-O-(tert-butyldiphenylsilyl)-2,3-dideoxy-β-D-glycero-pentofuranosyl>hypoxanthine 
• 120503-34-6 1-C-(6-chloropurin-N⁹-yl)-1,2,3-dideoxy-β-D-erythro-furanose 
• 260562-60-5 1-(5-O-tert-butyldimethylsilyl-3-O-phenoxythiocarbonyl-2-deoxy-β-D-erythro-pentofuranosyl)-imidazo[4,5-d]pyridazin-4(5H)-one 
• 890-38-0 2-deoxyinosine 
• 93778-57-5 9-((2R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)-1H-purin-6(9H)-one 
• 149656-26-8 1-O-acetyl-5-O-(tert-butyldiphenylsilyl)-2,3-dideoxy-2-(phenylselenenyl)-D-erythro-pentafuranose 
• 102717-29-3 (5S)-5-({[tert-butyl(diphenyl)silyl]oxy}methyl)dihydrofuran-2(3H)-one 
• 32780-07-7 (S)-5-(benzoyloxymethyl)tetrahydrofuran-2-one 
• 68-94-0 1,7-dihydro-6H-purin-6-one 
• 5983-09-5 2',3'-Dideoxyuridine 
• 68-94-0 hypoxanthine 
• 146469-96-7 hypoxanthine 

Downstream Products

• 130676-58-3 5'-O-acetyl-2',3'-dideoxyinosine 
• 117312-02-4 5'-benzoyl-2',3'-dideoxyinosine 
• 879015-30-2 5'-(2',3'-dideoxyinosine) mono 1,4-benzenedicarboxylic ester 
• 85326-06-3 2',3'-dideoxyguanosine 
• 107550-73-2 2,6-diaminopurine 2',3'-dideoxyriboside 
• 4097-22-7 2',3'-Dideoxyadenosine 
• 68-94-0 Allopurinol 
• 68-94-0 6-hydroxypurine 
• 5983-09-5 2',3'-Dideoxyuridine 
• 139300-68-8 Oxalic acid (2S,5R)-5-(6-hydroxy-purin-9-yl)-tetrahydro-furan-2-ylmethyl ester 4-nitro-phenyl ester 

Relevant academic research and scientific papers

Nucleoside phosphorylases from clostridium perfringens in the synthesis of 2',3'-dideoxyinosine

Four Clostridium perfringens phosphorylases were subcloned, overexpressed and analyzed for their substrate specificity. DeoD(1) and PunA could use a variety of purine substrates, including an antiviral drug 2',3'-dideoxyinosine (ddI). In one-pot synthesis using Clostridium phosphorylases, 2',3'-dideoxyuridine and hypoxanthine were converted to ddI at yield of about 30%. Copyright

Enzymatic Synthesis of Therapeutic Nucleosides using a Highly Versatile Purine Nucleoside 2’-DeoxyribosylTransferase from Trypanosoma brucei

The use of enzymes for the synthesis of nucleoside analogues offers several advantages over multistep chemical methods, including chemo-, regio- and stereoselectivity as well as milder reaction conditions. Herein, the production, characterization and utilization of a purine nucleoside 2’-deoxyribosyltransferase (PDT) from Trypanosoma brucei are reported. TbPDT is a dimer which displays not only excellent activity and stability over a broad range of temperatures (50–70 °C), pH (4–7) and ionic strength (0–500 mM NaCl) but also an unusual high stability under alkaline conditions (pH 8–10). TbPDT is shown to be proficient in the biosynthesis of numerous therapeutic nucleosides, including didanosine, vidarabine, cladribine, fludarabine and nelarabine. The structure-guided replacement of Val11 with either Ala or Ser resulted in variants with 2.8-fold greater activity. TbPDT was also covalently immobilized on glutaraldehyde-activated magnetic microspheres. MTbPDT3 was selected as the best derivative (4200 IU/g, activity recovery of 22 %), and could be easily recaptured and recycled for >25 reactions with negligible loss of activity. Finally, MTbPDT3 was successfully employed in the expedient synthesis of several nucleoside analogues. Taken together, our results support the notion that TbPDT has good potential as an industrial biocatalyst for the synthesis of a wide range of therapeutic nucleosides through an efficient and environmentally friendly methodology.

Developing a collection of immobilized nucleoside phosphorylases for the preparation of nucleoside analogues: Enzymatic synthesis of arabinosyladenine and 2',3'-dideoxyinosine

The use of nucleoside phosphorylases (NPs; EC 2.4.2.n) represents a convenient alternative to the chemical route for the synthesis of natural and modified nucleosides. We purified four recombinantly expressed nucleoside phosphorylases from the bacterial pathogens Citrobacter koseri, Clostridium perfringens, and Streptococcus pyogenes (CkPNPI, CkPNPII, CpUP, SpUP) and their substrate specificity was investigated towards either natural pyrimidine or purine nucleosides and some analogues, namely, arabinosyladenine (araA) and 2',3'-dideoxyinosine (ddI). A 2-3 % activity towards these latter compounds (compared to the natural substrates) was observed. Enzyme activities were compared to the specificities obtained for the enzymes pyrimidine nucleoside phosphorylase from Bacillus subtilis (BsPyNP) and purine nucleoside phosphorylase from Aeromonas hydrophila (AhPNPII) previously reported by some of the authors. The enzymes displaying the suitable specificity for the synthesis of araA and ddI were immobilized on aldehyde-agarose. The immobilized preparations were highly stable at alkaline pH and in the presence of methanol or acetonitrile as cosolvent. They were used in the synthesis of araA and ddI by a one-pot, bienzymatic transglycosylation achieving 74 and 44 % conversion, respectively. Something different: Nucleoside phosphorylases are a convenient alternative to the chemical route for the synthesis of natural and modified nucleosides. Four new nucleoside phosphorylases have been prepared, characterized, and tested for their use in biocatalyzed syntheses of araA and ddI (see scheme). A generally applicable immobilization technique has been found to provide active and stable biocatalysts.

Continuous flow photochemistry for the rapid and selective synthesis of 2′-deoxy and 2′,3′-dideoxynucleosides

A new photochemical flow reactor has been developed for the photo-induced electron-transfer deoxygenation reaction to produce 2′-deoxy and 2′,3′-dideoxynucleosides. The continuous flow format significantly improved both the efficiency and selectivity of the reaction, with the streamlined multi-step sequence directly furnishing the highly desired unprotected deoxynucleosides.

Use of Citrobacter koseri whole cells for the production of arabinonucleosides: A larger scale approach

Purine arabinosides are well known antiviral and antineoplastic drugs. Since their chemical synthesis is complex, time-consuming, and polluting, enzymatic synthesis provides an advantageous alternative. In this work, we describe the microbial whole cell synthesis of purine arabinosides through nucleoside phosphorylase-catalyzed transglycosylation starting from their pyrimidine precursors. By screening of our microbial collection, Citrobacter koseri (CECT 856) was selected as the best biocatalyst for the proposed biotransformation. In order to enlarge the scale of the transformations to 150 mL for future industrial applications, the biocatalyst immobilization by entrapment techniques and its behavior in different reactor configurations, considering both batch and continuous processes, were analyzed. C. koseri immobilized in agarose could be used up to 68 times and the storage stability was at least 9 months. By this approach, fludarabine (58% yield in 14 h), vidarabine (71% yield in 26 h) and 2,6-diaminopurine arabinoside (77% yield in 24 h), were prepared.

Continuous flow photocatalysis enhanced using an aluminum mirror: Rapid and selective synthesis of 2′-deoxy and 2′,3′-dideoxynucleosides

A unique photochemical flow reactor featuring quartz tubing, an aluminum mirror and temperature control has been developed for the photo-induced electron-transfer deoxygenation reaction to produce 2′-deoxy and 2′,3′-dideoxynucleosides. The continuous flow format significantly increased the efficiency and selectivity of the reaction.

Aeromonas hydrophila strains as biocatalysts for transglycosylation

Microbial transglycosylation is useful as a green alternative in the preparation of purine nucleosides and analogues, especially for those that display pharmacological activities. In a search for new transglycosylation biocatalysts, two Aeromonas hydrophila strains were selected. The substrate specificity of both micro-organisms was studied and, as a result, several nucleoside analogues have been prepared. Among them, ribavirin, a broad spectrum antiviral, and the well-known anti HIV didanosine, were prepared, in 77 and 62% yield using A. hydrophila CECT 4226 and A. hydrophila CECT 4221, respectively. In order to scale-up the processes, the reaction conditions, product purification and biocatalyst preparation were analyzed and optimized.

A PROCESS FOR PREPARING DIDANOSINE

This invention provides a method for preparing didanosine. The method comprises removing a protecting group in position 5' of compound II by hydrolysis under basic reaction conditions, and simultaneously enolizing of the carbonyl group of the purine ring to obtain a stable salt, and then producing the salt of 2',3-dideoxyinosine through catalytic hydrogenation, which salt is finally converted with acid to yield the finished product.

A NOVEL PROCESS FOR THE PREPARATION OF DIDANOSINE USING NOVEL INTERMEDIATES

The present invention relates to novel crystalline alkali metal and alkaline earth metal salts of 2',3'-dideoxy-2',3'-didehydroinosine. The present invention also provides a novel process for preparation of didanosine in high yield and purity using novel intermediates. Thus, for example, 5'-O-acetyl-2',3'-dideoxy-2',3'-didehydroinosine is reacted with monomethyl amine to give 2',3'-dideoxy-2',3'-didehydro inosine, which is then reacted with sodium hydroxide and crystallized to give crystalline 2',3'-dideoxy-2',3'-didehydroinosine sodium salt. 2',3'-Dideoxy-2',3'-didehydroinosine sodium salt is hydrogenated using raney nickel catalyst in aqueous medium and then neutralized with hydrochloric acid to yield didanosine.

METHOD FOR PRODUCING NUCLEOSIDE DERIVATIVE

The present invention relates to a method for producing a nucleoside derivative represented by formula (2), comprising the step of reducing a nucleoside of formula (1) in the presence of a noble metal catalyst comprising a carrier and a noble metal supported thereby, selected from the group consisting of (A) a homogeneously supported catalyst where the specific surface area of the noble metal is 95.0 m2/g or more and the particle size of the noble metal is 4.3 nm or less, and (B) a surface-loaded catalyst where the specific surface area of the noble metal is 56.0 m2/g or more and the particle size of the noble metal is 8.0 nm or less, wherein R1 is hydrogen or a protective group, R2 is NH2 or OH, R3 is an acyl group, and X is a chlorine or bromine atom. According to the present invention, the yield can be made equal even when the amount of catalyst is smaller than that used for the conventional products.