The present invention discloses oxazolidinone compounds of Formula (I): (I) and pharmaceutically acceptable salts thereof, wherein A and E, are as defined herein. The present invention also relates to compositions which comprise at least one oxazolidinone compound of the invention. The invention also provides methods for inhibiting growth of mycobacterial cells as well as a method of treating mycobacterial infections by Mycobacterium tuberculosis comprising administering a therapeutically effective amount of an oxazolidinone of the invention and/or a pharmaceutically acceptable salt thereof, or a composition comprising such compound and/or salt.

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The present invention relates to a chiral spiro phosphine-nitrogen-sulfur (PNS) tridentate ligand, preparation method and application thereof. The PNS tridentate ligand is a compound represented by Formula I or Formula II, their racemates, optical isomers, or catalytically acceptable salts thereof. The ligand has a primary structure skeleton characterized as a chiral spiro indan skeleton structure with a thio group. The chiral spiro phosphine-nitrogen-sulfur tridentate ligand can be synthesized by reacting racemic or optical active compound 7-diary/alkyl phosphine-7-amino-1, 1-spiro-dihydro-indene compound having a spiro-dihydro-indene skeleton as the starting material. The chiral spiro PNS tridentate ligand being complex with transition metal salt can be used in an asymmetric catalytic hydrogenation reaction for catalyzing carbonyl compound. In particular, in asymmetric hydrogenation reaction process, being complex with iridium for catalyzing -alkyl--keto ester can obtain a high catalytic activity (a catalyst amount of 0.0002% mol) and high enantioselectivity (up to 99.9% ee) result. So the present invention has a practical value for industrial and commercial production. ##STR00001##

This invention relates to a compound comprising a structure of formula (I): cyclic disulfide moiety-phosphorus coupling group (I). The cyclic disulfide moiety has the structure of (C-I), (C-II), or (C-III). This invention also relates to an oligonucleotide comprising one or more compounds that comprise the structure of formula (I), wherein at least one phosphorus coupling group contains a nucleoside or oligonucleotide. The invention also relates to a pharmaceutical composition comprising the oligonucleotide described herein and a method of reducing or inhibiting the expression of a target gene by administering to the subject a therapeutically effective amount of the oligonucleotide described herein.

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The present invention relates to a chiral spiro phosphine-nitrogen-sulfur (PNS) tridentate ligand, preparation method and application thereof. The PNS tridentate ligand is a compound represented by Formula I or Formula II, their racemates, optical isomers, or catalytically acceptable salts thereof. The ligand has a primary structure skeleton characterized as a chiral spiro indan skeleton structure with a thio group. The chiral spiro phosphine-nitrogen-sulfur tridentate ligand can be synthesized by reacting racemic or optical active compound 7-diary/alkyl phosphine-7-amino-1,1-spiro-dihydro-indene compound having a spiro-dihydro-indene skeleton as the starting material. The chiral spiro PNS tridentate ligand being complex with transition metal salt can be used in an asymmetric catalytic hydrogenation reaction for catalyzing carbonyl compound. In particular, in asymmetric hydrogenation reaction process, being complex with iridium for catalyzing -alkyl--keto ester can obtain a high catalytic activity (a catalyst amount of 0.0002% mol) and high enantioselectivity (up to 99.9% ee) result. So the present invention has a practical value for industrial and commercial production.

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A novel delivery system for drugs, and especially macromolecules such as proteins or oligonucleotides through biological membranes is provided, and specifically delivery of siRNA The delivery system comprises conjugation of the macromolecule drug to a moiety that enables effective passage through the membranes. Respectively, novel compounds and pharmaceutical compositions are provided, utilizing said delivery system. In one aspect of the invention, the compounds may be utilized in medical practice, for example, in delivery of siRNA or antisense oligonucleotides across biological membranes for the treatment of medical disorders.

The present invention relates to disulfide masked prodrug compounds of formula I, compositions and methods that are amenable to bioactivation by a reducing agent such as glutathione:
WP(V)LG(Formula I),
wherein P(V)LG is a pentavalent phosphorus leaving group; and W is: ##STR00001##
wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are as defined in the specification. Such disulfide based compounds, compositions, and methods can be useful, for example, in providing novel prodrugs for use as therapeutics. Once administered, the prodrug is metabolized in vivo into an active metabolite in a process termed bioactivation.

The present invention relates to disulfide masked prodrug compounds of Formula (I), nucleoside kinase bypass compositions thereof and methods that are amenable to bioactivation by a reducing agent such as glutathione: ##STR00001## Such disulfide based compounds, compositions, and methods can be useful, for example, in providing prodrugs for use as therapeutics.

The present invention discloses oxazolidinone compounds of Formula (I): (I) and pharmaceutically acceptable salts thereof, wherein A and E, are as defined herein. The present invention also relates to compositions which comprise at least one oxazolidinone compound of the invention. The invention also provides methods for inhibiting growth of mycobacterial cells as well as a method of treating mycobacterial infections by Mycobacterium tuberculosis comprising administering a therapeutically effective amount of an oxazolidinone of the invention and/or a pharmaceutically acceptable salt thereof, or a composition comprising such compound and/or salt. ##STR00001##