Deoxy sugar analogues of triciribine: correlation of antiviral and antiproliferative activity with intracellular phosphorylation

An Expeditious Total Synthesis of 5'-Deoxy-toyocamycin and 5'-Deoxysangivamycin

In present paper, an expeditious total synthesis of naturally occurring 5′-deoxytoyocamycin and 5′-deoxysangivamycin was accomplished. Because of the introduction of a benzoyl group at N-6 of 4-amino-5-cyano-6-bromo-pyrrolo[2,3-d]pyrimidine, a Vorbrüggen glycosylation with 1,2,3-tri-O-acetyl-5-deoxy-β-D-ribofuranose afforded a completely regioselective N-9 glycosylation product, which is unambiguously confirmed by X-ray diffraction analysis. All of the involved intermediates were well characterized by various spectra.

Pyrroloaryls and pyrroloheteroaryls: Inhibitors of the HIV fusion/attachment, reverse transcriptase and integrase

Heterocyclic compounds execute a very important role in drug design and discovery. This article provides the basic milestones of the research for pyrroloaryl and pyrroloheteroaryl based components targeting HIV viral replication cycle. Anti-HIV activity is elaborated for several classes of pyrrolo-compounds as pyrrolopyridines, pyrrolopyrimidines, pyrrolopyridazines, pyrrolobenzodiazepinones, pyrrolobenzothiazepines, pyrrolobenzoxazepinones, pyrrolophenanthridines, pyrroloquinoxalines, pyrrolotriazines, pyrroloquinolines, pyrrolopyrazinones, pyrrolothiatriazines, arylthiopyrroles and pyrrolopyrazolones targeting two essential HIV enzymes, reverse transcriptase and integrase as well as attachment/fusion of HIV virons to the host CD-4 cell. Such attempts were resulted in a discovery of highly potent anti-HIV agents suitable for clinical trials, for example, BMS-378806, BMS-585248, BMS-626529, BMS-663068, BMS-488043 and BMS-663749, etc. as anti-HIV attachment agents, triciribine, QX432, BI-1 and BI-2 as HIV RT inhibitors which are in preclinical or clinical development. Mechanism of action of compounds presented in this article towards the suppression of HIV attachment/fusion as well as against the activities of HIV enzymes reverse transcriptase and integrase has been discussed. Relationships of new compounds' molecular framework and HIV viral target has been overviewed in order to facilitate further construction of promising anti-HIV agents in future drug discovery process.

2-azapurine nucleosides: synthesis, properties, and base pairing of oligonucleotides

This review deals with 2-azapurine (imidazo[4,5-d] [1,2,3]triazine) nucleosides and closely related analogs. Different routes are described to yield the desired target compounds, including a sequence of ring-opening and ring-closure reactions performed on purine nucleosides or direct glycosylation of a 2-azapurine nucleobase with a sugar halide. Further, physical and spectroscopic properties of 2-azapurine nucleosides are discussed, including fluorescence, (13)C-NMR data, single-crystal X-ray analyses, and conformation studies on selected compounds; new biological data are presented. The second part of this review is dedicated to oligonucleotides containing 2-azapurines, including building-block (phosphoramidite) preparation and their use in solid-phase oligonucleotide synthesis. Base-pairing properties of 2-azapurine nucleosides as surrogates of canonical constituents of DNA were evaluated.

Inhibition of human immunodeficiency virus type 1 by triciribine involves the accessory protein nef

Triciribine (TCN) is a tricyclic nucleoside that inhibits human immunodeficiency virus type 1 (HIV-1) replication by a unique mechanism not involving the inhibition of enzymes directly involved in viral replication. This activity requires the phosphorylation of TCN to its 5' monophosphate by intracellular adenosine kinase. New testing with a panel of HIV and simian immunodeficiency virus isolates, including low-passage-number clinical isolates and selected subgroups of HIV-1, multidrug resistant HIV-1, and HIV-2, has demonstrated that TCN has broad antiretroviral activity. It was active in cell lines chronically infected with HIV-1 in which the provirus was integrated into chromosomal DNA, thereby indicating that TCN inhibits a late process in virus replication. The selection of TCN-resistant HIV-1 isolates resulted in up to a 750-fold increase in the level of resistance to the drug. DNA sequence analysis of highly resistant isolate HIV-1(H10) found five point mutations in the HIV-1 gene nef, resulting in five different amino acid changes. DNA sequencing of the other TCN-resistant isolates identified at least one and up to three of the same mutations observed in isolate HIV-1(H10). Transfer of the mutations from TCN-resistant isolate HIV-1(H10) to wild-type virus and subsequent viral growth experiments with increasing concentrations of TCN demonstrated resistance to the drug. We conclude that TCN is a late-phase inhibitor of HIV-1 replication and that mutations in nef are necessary and sufficient for TCN resistance.

Gene expression associations with the growth inhibitory effects of small molecules on live cells: specificity of effects and uniformity of mechanisms

The NCI60 human tumor cell line screen is a public resource for studying selective and non-selective growth inhibition of small molecules against cancer cells. By coupling growth inhibition screening data with biological characterizations of the different cell lines, it becomes possible to infer mechanisms of action underlying some of the observable patterns of selective activity. Using these data, mechanistic relationships have been identified including specific associations between single genes and small families of closely related compounds, and less specific relationships between biological processes involving several cooperating genes and broader families of compounds. Here we aim to characterize the degree to which such specific and general relationships are present in these data. A related question is whether genes tend to act with a uniform mechanism for all associated compounds, or whether multiple mechanisms are commonly involved. We address these two issues in a statistical framework placing special emphasis on the effects of measurement error in the gene expression and chemical screening data. We find that as measurement accuracy increases, the pattern of apparent associations shifts from one dominated by isolated gene/compound pairs, to one in which families consisting of an average of 25 compounds are associated to the same gene. At the same time, the number of genes that appear to play a role in influencing compound activities decreases. For less than half of the genes, the presence of both positive and negative correlations indicates pleiotropic associations with molecules via different mechanisms of action.

Deoxygenation of 5-O-benzoyl-1,2-isopropylidene-3-O-imidazolylthiocarbonyl-α-d-xylofuranose using dimethyl phosphite: an efficient alternate method towards a 3'-deoxynucleoside glycosyl donor

An efficient radical deoxygenation reaction of thiocarbonylimidazolyl activated glycoside analogue using dimethyl phosphite as hydrogen source and radical chain carrier was performed as a key step in a multi step synthesis towards a common 3-deoxy glycosyl donor for 3′-deoxynucleosides. This method has safety and cost advantages compared to the generally used radical reduction reagents.

Synthesis of Non-Nucleosides: 7- and 1,3-Substituents of New Pyrrolo[2,3-d]pyrimidin-4-ones on Antiviral Activity

A series of non-nucleosides 9-47 were synthesized. Compounds 1-4 were reacted with formic acid (85%) to afford compounds 5-8. Then, the latter compounds were reacted with alkyl halides a-f (2-bromopropane, 2-bromobutane, benzyl bromide, benzyl chloromethyl ether, chloromethyl ethyl ether, phenacyl bromide) in the presence of NaH in dry DMF to give the desired compounds 9-47, which were evaluated for activity against herpes simplex virus type-II (HSV-II).

The syntheses and properties of tricyclic pyrrolo[2,3-d]pyrimidine analogues of S6-methylthioguanine and O6-methylguanine

The syntheses of novel tricyclic pyrrolo[2,3-d]pyrimidine analogues of S6-methylthioguanine are described. The crystal structures and pKa values of these and related O6-methylguanine analogues are reported. All compounds display higher pKa values than O6-methylguanine with the sulfur-containing analogues being the more basic and exhibiting higher stability in aqueous solution. In a standard substrate assay with the human repair protein O6-methylguanine-DNA methyltransferase (MGMT) only the oxygen-containing analogue displayed activity.

Synthesis of new 2'-beta-C-methyl related triciribine analogues as anti-HCV agents

Ten new beta-D-ribofuranosyl and 2'-beta-C-methyl-beta-D-ribofuranosyl triciribine derivatives 4-13 with various N4 and 6-N substituents on the tricyclic ring were synthesized from the corresponding toyocamycin and new 2'-beta-C-methyl toyocamycin derivatives. The inhibitory studies of these compounds in the HCV replicon assay reveal that some of them possess interesting anti-HCV properties with low cytotoxicity.

An improved total synthesis of triciribine: a tricyclic nucleoside with antineoplastic and antiviral properties

We describe an efficient total synthesis of triciribine, a tricyclic nucleoside with antineoplastic and antiviral properties, starting from 4-amino-6-bromo-5-cyanopyrrolo[2,3-d]pyrimidine.

Synthesis and antiviral activity of 2-substituted analogs of triciribine

Triciribine (TCN) and triciribine monophosphate (TCN-P) have antiviral and antineoplastic activity at low or submicromolar concentrations. In an effort to improve and better understand this activity, we have conducted a structure-activity relationship study to explore the effect of substitutions at the 2-position of triciribine. 2-Methyl- (2-Me-TCN), 2-ethyl- (2-Et-TCN), 2-phenyl- (2-Ph-TCN), 2-chloro- (2-Cl-TCN), and 2-aminotriciribine (2-NH2-TCN) were designed and synthesized to determine the effects of substitutions at the 2-position which change the steric, electronic, and hydrophobic properties of TCN, while maintaining the integrity of the tricyclic ring system. These compounds were evaluated for activity against human immunodeficiency virus (HIV-1), herpes simplex virus type 1 (HSV-1), and human cytomegalovirus (HCMV) and were found to be either less active than TCN and TCN-P or inactive at the highest concentrations tested, 100 microM. We conclude that substitutions at the 2-position of triciribine adversely affect the antiviral activity most likely because these analogs are not phosphorylated to active metabolites.

A rational approach to personalized anticancer therapy: chemoinformatic analysis reveals mechanistic gene-drug associations

PURPOSE

To predict the response of cells to chemotherapeutic agents based on gene expression profiles, we performed a chemoinformatic study of a set of standard anticancer agents assayed for activity against a panel of 60 human tumor-derived cell lines from the Developmental Therapeutics Program (DTP) at the National Cancer Institute (NCI).

METHODS

Mechanistically-relevant gene:drug activity associations were identified in the scientific literature. The correlations between expression levels of drug target genes and the activity of the drugs against the NCI's 60 cell line panel were calculated across and within each tumor tissue type, using published drug activity and gene expression data.

RESULTS

Compared to other mechanistically-relevant gene-drug associations, that of triciribine phosphate (TCN-P) and adenosine kinase (ADK) was exceptionally strong--overall and within tumor tissue types-across the 60 cell lines profiled for chemosensitivity (1) and gene expression (2).

CONCLUSION

The results suggest ADK expression may be useful for stratifying TCN-P-responsive vs. non-responsive tumors. Based on TCN-P's mechanism of action and the observed TCN-P:ADK association, we contend that catalytic drug activation provides a rational, mechanistic basis for personalizing cancer treatment based on tumor-specific differences in the expression of drug-activating enzymes.

Synthesis of carbocyclic analogs of 2',3'-dideoxysangivamycin, 2',3'-dideoxytoyocamycin, and 2',3'-dideoxytriciribine

Syntheses and antiviral activity of new carbocyclic analogs of 2', 3'-dideoxysangivamycin, 2',3'-dideoxytoyocamycin and 2',3'-dideoxytriciribine is described. The key intermediate, carbocyclic 4-chloro-5-iodopyrrolopyrimidine. was synthesized in good yield via a novel iodination method using I2 and CF3COOAg. This carbocyclic 4-chloro-5-iodopyrrolopyrimidine then allowed for a concise synthesis of the desired 4,5-disubstituted carbocyclic nucleosides.