PubMed Health⌕ Search

Biomedical subjects

I I Fedorov

Publications and source records attributed to I I Fedorov.

At least 19 recordsLinked to original sources

Novel 3'-C/N-substituted 2',3'-beta-D-dideoxynucleosides as potential chemotherapeutic agents. 1. Thymidine derivatives: synthesis, structure, and broad spectrum antiviral properties.

A synthetic scheme for the 3'-oxime derivatives 3E, 5E, 5Z, 7E and 7Z of 1-(2,3-dideoxy-beta-D-glycero-pentofuranosyl)thymine and for 1-(2,3-dideoxy-3-nitro-beta-D-erythro-pentofuranosyl)-thymine (10) has been developed starting from appropriately 5'-protected 3'-ketothymidine. X-ray analysis showed that 3'-N-hydroxyimino 3E and 3'-N-methoxyimino 5Z derivatives have close molecular conformations: anti about the N1-C1' bond, and gauche+ about the C4'-C5' exocyclic bond. Their sugar conformations are C1'-exo-O4'-endo and C1'-exo-C2'-endo, respectively. The antiviral assays in cell cultures demonstrated that 3'-N-hydroxyimino 3E and 3'-N-acetoxyimino 7E + 7Z derivatives are endowed with significant activity against human immunodeficiency virus (HIV) with EC50 values ranging between 0.02 and 0.40 microgram/mL for both HIV-1 and HIV-2. The other compounds 5E + 5Z and 10 were at least 2 orders of magnitude less active. The 3'-N-hydroxyimino derivative 3E also shows promising activity against hepatitis B virus (HBV) (EC50 = 0.25 microgram/mL) and against herpes simplex virus type 1 (HSV-1) and HSV-2.

Antiviral Agents↗

Lymphatic distribution of 3'-azido-3'-deoxythymidine and 3'-azido-2',3'-dideoxyuridine in mice.

Recently, it was shown that human immunodeficiency virus (HIV)-infected cells preferentially locate in lymphoid tissue early in the course of infection. Therefore, it is important to characterize the disposition of the anti-HIV agents, 3'-azido-3'-deoxythymidine (AZT) and 3'-azido-2', 3'-dideoxyuridine (AZdU), in the lymphatic system. The disposition of AZT and AZdU in serum and neck, axillary, and mesenteric lymph nodes was studied in mice after intravenous, oral, and intraperitoneal administrations of 50 mg/kg doses. Samples were collected at 0.08, 0.5, 1, 2, 3, 4, and 6 hr after dosing and nucleoside concentrations were determined by HPLC. Pharmacokinetic parameters were estimated using noncompartmental analysis. Maximum concentration, half-life, and area under the serum concentration vs. time curve (AUC) obtained from the serum concentration data were similar for both compounds after intravenous and intraperitoneal administrations; however, a difference in oral bioavailability for AZT and AZdU (49% and 76%, respectively) was noted. Patterns of regional distribution in lymph nodes were similar for both drugs; however, the accumulation of AZdU in the various lymph nodes, according to AUC values, was 3-76% greater than that for AZT. The relative exposure re = AUClymph/AUCserum) of both nucleosides exhibited a dependence on route of administration. Intravenous and oral administrations resulted in a greater distribution of nucleoside into axillary lymph nodes, compared with neck and mesenteric lymph nodes. Following intraperitoneal administration, however, distribution was similar in all three regions. AZT and AZdU distribute into the lymphatic system; however, AZdU accumulation was greater than that of AZT.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

3'-C-branched 2'-deoxy-5-methyluridines: synthesis, enzyme inhibition, and antiviral properties.

A synthesis scheme for 3'-C-methyl-2'-deoxynucleosides and 3'-C-methylidene-2',3'-dideoxy-5-methyluridine has been proposed with 2-deoxyribose as the starting material. Methyl 5-O-benzoyl-2-deoxyribofuranose was oxidized and the mixture of the 3'-keto derivatives was separated into the alpha- and beta-anomers. The beta-keto derivative was converted by reaction with MeMgBr, and after reaction with thymine and subsequent deprotection 1-(3'-C-methyl-2'-alpha-deoxy-alpha-D-threo-pentofuranosyl)thymine and its beta-anomer were obtained. The same reactions with the alpha-keto sugar gave 1-(3'-C-methyl-2'-deoxy-alpha-D-erythro-pentofuranosyl)thymine and its beta-anomer. 1-(5-O-Benzoyl-3'-C-methyl-2'-deoxy-alpha-D-threo-pentofuranosyl)thymine was converted to a mixture of 3'-C-methylidene-2',3'-dideoxy-5-methyluridine and 3'-C-methyl-2',3'-dideoxy-2',3'-didehydro-5-methyluridine, which were separated. The stereoselectivity of the Grignard reagent's attachment to 2-deoxyfuranose 3-ulosides has been ruled by the substitute configuration at Cl. Also, the effect of the hydroxyl or OBz group configuration at C3 on the condensation stereoselectivity of 3-C-methyl-2-deoxyfuranosides with silylated thymine has been studied. The structure of the obtained compounds was proved by 1H NMR UV, 13C NMR, and CD spectroscopy, as well as elemental (C, H, N) analysis. The C2'-endo-C1'-exo conformation, the anti conformation of thymine in relation to the glycosidic bond, and the gauche+conformation in relation to the C4'-C5' bond are characteristic for the 3'-C-methyl-2'-deoxythymidine structure in the crystals. 3'-C-Methyl-2'-deoxythymidine 5'-triphosphate was synthesized and proved to be a competitive inhibitor, with respect to dTTP, of a number of DNA polymerases, including the reverse transcriptases of human immunodeficiency virus type 1 (HIV-1) and avian myeloblastosis virus (AMV). None of the DNA polymerases examined were able to incorporate this compound into the growing DNA chain. In contrast, 3'-C-methylidene-2',3'-dideoxy-5-methyluridine 5'-triphosphate was found to be incorporated at the 3'-end of the DNA chain by HIV-1 reverse transcriptase, albeit with very low efficiency. 3'-C-Methyl-2'-deoxy-5-methyluridine did not suppress HIV-1 replication in MT-4 cells at 500 microM while its 5'-phosphite derivative exhibited modest anti-HIV-1 activity.

Antiviral Agents↗

[Molecular and crystalline structure of 3'-methylamino-2',3'-dideoxyribosylthymine--a potential inhibitor of HIV].

The structure of 3'-methylamino-2',3'-dideoxyribosylthymine [ddT(3'NHMe)] was determined by X-ray analysis. The space group is P2(1)2(1)2(1). Cell dimensions are: a 5.132(1), b 13.718(1), c 16.947(2) A, V 1193.2 A3, Z 4. The structure was solved by directed methods and refined by the full-matrix least square method to R 4.8%. The molecule of ddT(3'NHMe) has anti-conformation with respect to the glycosidic bond (chi (O4'-C1'-N1-C2) = -106.7 degrees), C3'-endo-C4'-exo puckering of the sugar moiety (P -28.8 degrees, psi m -31.5 degrees) and gauche-gauche conformation about exocyclic C4'-C5' bond (psi(C3'-C4'-C5'-O5') 45.8 degrees). The structure of ddT(3'NHMe) was compared with those of 3'-amino-3'-deoxythymidine, 3'-azido-3'-deoxythymidine and natural thymidine.

Antiviral Agents↗

[Adducts of 3'-azido-2,3'-dideoxythymidine 5'-phosphate or 5'-phosphonate as inhibitors of cytopathic effect and transformation of cells under the influence of retroviruses in cell culture].

Inhibition of HIV-1- or HIV-2-induced cytopathicity and (Moloney) murine sarcoma virus (MSV)-induced cell transformation by amino acid and amino alcohol adducts of either 3'-azido-2',3'-dideoxythymidine 5'-monophosphate (AZTMP) or 5'-hydrogenphosphonate (AZTHP) were investigated. Both types of nucleotide adducts inhibited replication of HIV-1 and HIV-2 in MT-4 cells at a 1.5- to 3-fold higher EC50 (50% effective concentration) than AZT; and, also, selectivity indexes of these adducts were approximately 1.5 to 3-fold lower than that of AZT. The activity of the AZTMP and AZTHP adducts against MSV-induced transformation of C3H/3T3 cells was equal to or only slightly inferior than that of AZT, but their toxicity was 10-fold lower, so that their selectivity indexes were 2- to 7-fold higher. The nature of the aminoacyl component of the adducts significantly influence the antiretroviral activity of the test compounds.

3T3 Cells↗