Abstract: The present invention relates to pharmaceutically active ornithine compounds, particularly to pharmaceutically acceptable ammonium salts of N?-acyl derivatives of N?(4-amino-4-deoxypteroyl)-L-ornithine compounds; and methods of treatment and pharmaceutical compositions that utilize or comprise one or more of such ammonium salts. The ammonium salts provided by the invention exhibit superior chemical stability than corresponding acidic N?-acyl derivatives of N?-acyl derivatives of N?(4-amino-4-deoxypteroyl)-L-ornithine compounds.

Abstract: The present invention relates to dihydrofolate reductase inhibitors having an aromatic group and a heteroaromatic group linked by a methylene group; methods of preparation of dihydrofolate reductase inhibitors that include metal mediated cross coupling of an aromatic halide or heteroaromatic halide with an organozinc reagent; and methods of treatment and pharmaceutical compositions that utilize or comprise one or more of such dihydrofolate reductase inhibitors.

Abstract: The present invention relates to dihydrofolate reductase inhibitors having an aromatic group and a heteroaromatic group linked by a methylene group; and methods of treatment and pharmaceutical compositions that utilize or comprise one or more of such dihydrofolate reductase inhibitors.

Abstract: The present invention relates to dihydrofolate reductase inhibitors having an aromatic group and a heteroaromatic group linked by a methylene group; and methods of treatment and pharmaceutical compositions that utilize or comprise one or more of such dihydrofolate reductase inhibitors. More particularly, the present invention relates to dihydrofolate reductase inhibitors having a substituted aromatic group and a heteroaromatic group linked by a methylene group wherein at least one of the aromatic group substituents is a lipophilic residue comprising at least one acidic functional group.

Abstract: The invention relates to pharmaceutically active compounds, and methods of treatment and pharmaceutical compositions that utilize or comprise one or more such compounds. Compounds of the invention and particularly useful for the treatment or prophylaxis of diseases associated with parasitic infection such as pneumocystis pneumonia, toxoplasmosis, cryptosporidiosis, leischmaniasis and malaria.

Abstract: The present invention relates to pharmaceutically active ornithine compounds, particularly to pharmaceutically acceptable ammonium salts of N?-acyl derivatives of N?(4-amino-4-deoxypteroyl)-L-ornithine compounds; and methods of treatment and pharmaceutical compositions that utilize or comprise one or more of such ammonium salts. The ammonium salts provided by the invention exhibit superior chemical stability than corresponding acidic N?-acyl derivatives of N?-acyl derivatives of N?(4-amino-4-deoxypteroyl)-L-ornithine compounds.

Abstract: In one embodiment, the present invention relates to a new class of ammonium salts of N?-acyl derivatives of N?-(4-amino-4-deoxypteroyl)-L-ornithine compounds having a structure according to formula II-IV. Formula II has the structure of: wherein: R2 represents up to four groups independently selected at each occurrence of R2 from the group consisting of hydrogen, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-8 cycloalkyl, C1-6 alkoxy, chloro, fluoro, hydroxy, and —COOH; R3, R4, and R5 are each independently selected from hydrogen and C1-6 alkyl; or NR3R4 taken combination can form a 5 to 7 member heterocycle having at least one nitrogen ring atom; and x is a real number greater than 0 and less than about 4. The ammonium salts provided by the invention exhibit high inhibitory activity against the growth o methotrexate-resistant cells, and also exhibit superior chemical stability than corresponding acidic N?-acyl derivatives of N?-acyl derivatives of N?(4-amino-4-deoxypteroyl)-L-ornithine compounds.

Abstract: The present invention relates to dihydrofolate reductase inhibitors having an aromatic group and a heteroaromatic group linked by a methylene group; methods of preparation of dihydrofolate reductase inhibitors that include metal mediated cross coupling of an aromatic halide or heteroaromatic halide with an organozinc reagent; and methods of treatment and pharmaceutical compositions that utilize or comprise one or more of such dihydrofolate reductase inhibitors.

Abstract: The present invention relates to dihydrofolate reductase inhibitors having an aromatic group and a heteroaromatic group linked by a methylene group; and methods of treatment and pharmaceutical compositions that utilize or comprise one or more of such dihydrofolate reductase inhibitors.

Abstract: A positron source is applicable particularly to solid state physics, including a thin target receiving a continuous or practically continuous 10 MeV electron beam in grazing incidence and generating positrons upon interaction with this beam.

Abstract: This source is applicable particularly to solid state physics and comprises a thin target (28) receiving a continuous or practically continuous 10 MeV electron beam (22) in grazing incidence and generating positrons with interaction with this beam.

Abstract: The present invention relates to pharmaceutically active ornithine compounds, particularly to pharmaceutically acceptable ammonium salts of N&dgr;-acyl derivatives of N&agr;(4-amino-4-deoxypteroyl)-L-omithine compounds; and methods of treatment and pharmaceutical compositions that utilize or comprise one or more of such ammonium salts. The ammonium salts provided by the invention exhibit superior chemical stability than corresponding acidic N&dgr;-acyl derivatives of N&dgr;-acyl derivatives of N&agr;(4-amino-4-deoxypteroyl)-L-ornithine compounds.

Abstract: The invention provides lipophilic phosphonoacid/nucleoside conjugates that exhibit exceptional antiviral activity, including activity against drug-resistant HIV strains. Compounds of the invention include phosphonoacid/nucleoside conjugates where the carboxyl group and phosphonyl groups of the phosphonacid are esterified whereby the compound contains at least one lipophilic group and at least one nucleoside group.

Abstract: 2-Aza-2-desamino analogues of 5,8-dideazafolic acid, which analogues have the formula ##STR1## wherein X is an aryl or heteroaryl moiety;R.sup.1 is H, C.sub.1 -C.sub.4 alkyl, C.sub.3 -C.sub.4 alkenyl, or C.sub.3 -C.sub.4 alkynyl; andR.sup.2 is OH, an L-.alpha.-amino acid, or a peptide comprising L-.alpha.-amino acids.

Abstract: Compounds having the structure ##STR1## in which R is alkyl, aryl, or aralkyl, A is hydrogen or a water-soluble cation, B is hydrogen, fluorine, or azido, the bond is saturated when B is fluorine or azido and is saturated or unsaturated when B is hydrogen, and D is a purine or pyrimidine base are effective inhibitors of retrovirus replication.

Abstract: A compound having the structure ##STR1## in which R.sub.1 is hydrogen or a lower alkyl group and R.sub.2 is hydrogen or methyl.

Abstract: Compounds having the structure ##STR1## in which R is --CO--Ar--COOR.sub.1 where R.sub.1 is hydrogen or lower alkyl, and pharmaceutical compositions containing the same exhibiting high growth inhibitory activity against methotrexate resistant cells.

Abstract: Cysteic acid and homocysteic acid analogues of methotrexate and aminopterin having antitumor activity and low toxicity are soluble in water at a physiological pH ranging from 7.2-7.5.