Abstract: A phosphonate nucleotide compound represented by the following formula (I) or a salt thereof, or a hydrate or solvate thereof: wherein, R1 is a hydroxyl group; each of R2 and R3 is independently a hydrogen atom, a C1-C22 alkyl group, an alkanoyloxymethyl group, an alkanoylthioethyl group, or an ethyl group substituted by one or more halogen atoms; R4 is a hydrogen atom, a C1-C4 alkyl group, a C1-C4 hydroxyalkyl group, or a C1-C4 alkyl group substituted by one or more halogen atoms; and X is CH or a nitrogen atom.

Abstract: Excellent remedies for hepatitis C which contain as the active ingredients a 3′-deoxy-3′-fluorouridine derivatives and a 1-(3′-deoxy-fluoro-&bgr;-L-ribofuranosyl)uracil derivative and show little side effects.

Abstract: The 2-amino-6-arylthiopurinephosphonate of the present invention has no toxicity such as bone marrow cell growth inhibition and mutagenicity, and has a high anti-viral activity, oral absorbency and safety. Furthermore, the compound of the present invention can be produced in a short process. Therefore, the present invention can provide an excellent anti-viral agent which can efficiently be produced.

Abstract: A compound represented by the following general formula (I) which has an antiviral activity: wherein R1 represents hydrogen atom, C1-C6 alkyl group, or C7-C10 aralkyl group; R2 represents C1-C6 alkyl group, C7-C10 aralkyl group, or phenyl group; R3 and R4 independently represent hydrogen atom, C1-C6 alkyl group, acyloxymethyl group, acylthioethyl group, or ethyl gorup substituted with at least one halogen atom; R5 represents hydrogen atom, C1-C4 alkyl gorup, C1-C4 hydroxyalkyl group, C1-C4 alkyl group substituted with at least one halogen atom; and X represents carbon atom or nitrogen atom.

Abstract: A phosphonate nucleotide compound represented by formula (I): (wherein R1 is a C1-C6 alkyl group or the like, R2 is a hydrogen atom, a C1-C4 alkyl group substituted by one or more halogen atoms or the like, R3 is a hydrogen atom, a C1-C4 alkyl group substituted by one or more halogen atoms or the like, R4 is a hydrogen atom, a C1-C4 alkyl group substituted by one or more halogen atoms and X is a carbon atom or a nitrogen atom), a salt thereof, a hydrate thereof or a solvate thereof, as well as a medicament containing the same. It is useful as an antiviral agent for human immunodeficiency virus, herpes simplex virus, hepatitis B virus or the like and as an antitumor agent.

Abstract: Phosphonate-nucleotide ester compounds of the formula (I) have excellent antiviral activity and antineoplastic activity. Further, they can be orally administered. ##STR1## wherein ring A represents ##STR2## wherein R.sup.1 and R.sup.2 independently represent hydrogen, halogen, hydroxyl, mercapto, C.sub.6 -C.sub.10 arylthio or amino; R.sup.3 represents C.sub.1 -C.sub.4 alkyl or ethyl having one or more substituents selected from the group consisting of fluorine, C.sub.1 -C.sub.4 alkoxy, phenoxy, C.sub.7 -C.sub.10 phenylalkoxy and C.sub.2 -C.sub.5 acyloxy; R.sup.4 represents ethyl having one or more substituents selected from the group consisting of fluorine, C.sub.1 -C.sub.4 alkoxy, phenoxy, C.sub.7 -C.sub.10 phenylalkoxy and C.sub.2 -C.sub.5 acyloxy; X, Y and Z independently represent methyne or nitrogen atom; or a pharmaceutically acceptable salt thereof.

Abstract: A phosphonate nucleotide compound having antiviral activity and is useful for an orally available and highly safe antiviral agent, which is represented by the following formula (I): ##STR1## wherein R.sup.1 represents hydrogen, a C.sub.1 -C.sub.6 alkoxy, a halogen-substituted C.sub.1 -C.sub.4 alkoxy, halogen, amino, or nitro; R.sup.2 and R.sup.3 independently represent hydrogen, a C.sub.1 -C.sub.22 alkyl, an acyloxymethy, an acylthioethyl, or a halogen-substituted ethyl; R.sup.4 represents hydrogen, a C.sub.1 -C.sub.4 alkyl, a C.sub.1 -C.sub.4 hydroxyalkyl, or a halogen-substituted C.sub.1 -C.sub.4 alkyl; and X represents carbon or nitrogen.

Abstract: Antiviral agents which comprises as active ingredients one or more 2',3'-dideoxyribonucleosides or phosphoric esters thereof and 6-benzyl-1-ethoxymethyl-5-substituted uracil derivative of the formula (I): ##STR1## wherein X is oxygen or sulfur atom; R.sup.1 is ethyl or isopropyl; R.sup.2 and R.sup.3 are independently hydrogen atom, C.sub.1 -C.sub.3 alkyl or halogen atom, which compounds can inhibit HIV reverse transcriptase through different mechanisms and are synergistic in combination.

Abstract: The disclosure concerns pyrimidine derivatives represented by the following general formulas [I] and [I'] and having antiviral activity, particularly antiretroviral activity such as anti-HIV activity: ##STR1## and pharmaceutical compositions having antiviral activity and comprising the above-described derivative(s) as an active ingredient.

Abstract: A pyrimidine nucleoside derivative and pharmaceutically acceptable salt thereof specified by the presence of ethyl group or isopropyl group at 5-position of the pyrimidine ring and the presence of a (substituted) phenylthio or a (substituted) benzyl group at 6-position of the pyrimidine ring is provided. The pyrimidine nucleoside derivative and pharmaceutically acceptable salt thereof show a markedly higher anti-retroviral activity than conventional analogous compounds and have a relatively low toxicity against the host cells, and therefore, are useful as an active ingredient of antiviral agent.

Abstract: A novel heterocyclic compound represented by the following formula (I): ##STR1## wherein X represents an oxygen atom or sulfur atom; R.sup.1 represents a hydrogen atom or halogen atom; R.sup.2 represents a C.sub.4 -C.sub.6 alkyl group, C.sub.2 -C.sub.10 alkoxyalkyl group, C.sub.3 -C.sub.15 alkenyl group, C.sub.7 -C.sub.12 aralkyl group, C.sub.8 -C.sub.18 aralkyloxyalkyl group, C.sub.7 -C.sub.12 aryloxyalkyl group, C.sub.3 -C.sub.10 alkynyl group, C.sub.4 -C.sub.12 alkadienyl group, C.sub.6 -C.sub.18 alkatrienyl group, C.sub.6 -C.sub.12 alkadiynyl group, or C.sub.6 -C.sub.12 alkatriynyl group, said aryloxyalkyl group, alkynyl group, alkadienyl group, alkatrienyl group, alkadiynyl group and alkatriynyl group being capable of having at least one substituent selected from the group consisting of halogen atoms, C.sub.1 -C.sub.4 alkyl group, C.sub.1 -C.sub.4 halogenated alkyl group, phenyl group, hydroxyl group and C.sub.1 -C.sub.4 alkoxy group; and each of R.sup.3 and R.sup.

Abstract: 6-substitutted acyclopyrimidine nucleoside derivatives represented by the following general formula I: ##STR1## wherein R.sup.1 represents a hydrogen or halogen atom or a group of alkyl, alkenyl, alkynyl, alkylcarbonyl, arylcarbonyl, arylcarbonylalkyl, arylthio or aralkyl; R.sup.2 represents a group of arylthio, alkylthio, cycloalkylthio, aryl sulfoxide, alkyl sulfoxide, cycloalkyl sulfoxide, alkenyl, alkynyl, aralkyl, arylcarbonyl, arylcarbonylalkyl or aryloxy; R.sup.3 represents a hydroxyalkyl group of which alkyl portion may contain an oxygen atom; X represents an oxygen or sulfur atom or amino group; Y represents an oxygen or sulfur atom; and A represents .dbd.N-- or --NH-- or pharmaceutically acceptable salts thereof, processes for their preparation and antiviral agents containing them as active ingredients.

Abstract: The disclosure concerns pyrimidine derivatives represented by the following general formulas [I] and [I′] and having antiviral activity, particularly antiretroviral activity such as anti-HIV activity: and pharmaceutical compositions having antiviral activity and comprising the above-described derivative(s) as an active ingredient.