Patents by Inventor Madhavi C. Chander
Madhavi C. Chander has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7153946Abstract: A molecular conjugate is provided having the formula: wherein R1 is a de-hydroxyl or de-amino moiety respectively of a hydroxyl-bearing or amino-bearing biologically active molecule or an analog or derivative thereof, and Z is —O— or —NH—, respectively, Y is a straight or branched alkyl having 1 to 20 carbons that may be optionally substituted with one or more phenyl, a cycloalkyl optionally substituted with one or more alkyl or phenyl, or an aromatic group optionally substituted with one or more alkyl groups, electron-withdrawing groups, or electron-donating groups; and R2 is —CH?CH(W), —CH(OH)CH(OH)W, or —C(O)H, where W can be H, a straight or branched alkyl having 1 to 20 carbons that may be optionally substituted with one or more phenyl, a cycloalkyl optionally substituted with one or more alkyl or phenyl, or an aromatic group optionally substituted with one or more alkyl groups, electron-withdrawing groups, or electron-donating groups.Type: GrantFiled: November 24, 2004Date of Patent: December 26, 2006Assignee: Tapestry Pharmaceuticals, Inc.Inventors: James D. McChesney, Madhavi C. Chander, Teruna J. Siahaan, Christine R. Xu, Sterling K. Ainsworth
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Patent number: 6825166Abstract: A molecular conjugate is provided having the formula: wherein n is the conjugation number, P is a moiety of a carrier molecule such as a protein, R1 is a moiety of a biologically active molecule or its analogs, derivatives, salts or secondary amines, Z is —O— or —NH—, and Y is a straight or branched alkyl having 1 to 20 carbons optionally substituted with one or more phenyl, a cycloalkyl optionally substituted with one or more alkyl or phenyl, or an aromatic group optionally substituted with one or more alkyl, electron-withdrawing or electron-donating groups. Compounds and methods useful in producing such molecular conjugates are also provided, as well as methods of concentrating biologically active molecules in selected target cells of a patient that comprise administering to the patient a selected dose of such molecular conjugates.Type: GrantFiled: March 25, 2002Date of Patent: November 30, 2004Assignee: Tapestry Pharmaceuticals, Inc.Inventors: James D. McChesney, Madhavi C. Chander, Teruna J. Siahaan, Christine R. Xu, Sterling K. Ainsworth
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Publication number: 20020198141Abstract: A molecular conjugate is provided having the formula: 1Type: ApplicationFiled: March 25, 2002Publication date: December 26, 2002Inventors: James D. McChesney, Madhavi C. Chander, Teruna J. Siahaan, Christine R. Xu
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Patent number: 6495705Abstract: The present invention describes a process for producing 10-deacetyl baccatin III from a solution containing a solvent reactive with hydrazine hydrate and a spectrum of taxanes. The solution is contacted with hydrazine hydrate thereby converting some taxanes therein into 10-deacetyl baccatin III. The process can target taxanes having an ester functionality on at least one of the C-10 and C-13 positions. The hydrazine hydrate cleaves the ester functionality of the taxane solute, The process may be used to produce 10-deacetyl baccatin III from a biomass extract by contacting the biomass extract with a mixture of a solvent and a hydrazine hydrate. The solvent may have a functional group that is cleaved by hydrazine. Acetate solvents are contemplated.Type: GrantFiled: July 5, 2001Date of Patent: December 17, 2002Assignee: NaPro BioTherapeutics, Inc.Inventors: Madhavi C. Chander, James D. McChesney
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Publication number: 20020042529Abstract: The present invention describes a process for producing 10-deacetyl baccatin III from a solution containing a solvent reactive with hydrazine hydrate and a spectrum of taxanes. The solution is contacted with hydrazine hydrate thereby converting some taxanes therein into 10-deacetyl baccatin III. The process can target taxanes having an ester functionality on at least one of the C-10 and C-13 positions. The hydrazine hydrate cleaves the ester functionality of the taxane solute. The process may be used to produce 10-deacetyl baccatin III from a biomass extract by contacting the biomass extract with a mixture of a solvent and a hydrazine hydrate. The solvent may have a functional group that is cleaved by hydrazine acetate. Acetate solvents are contemplated.Type: ApplicationFiled: July 5, 2001Publication date: April 11, 2002Inventors: Madhavi C. Chander, James D. McChesney
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Patent number: 6281368Abstract: A process for producing 10-deacetyl baccatin III from an acidic solution containing a spectrum of taxanes, comprising contacting the acidic solution containing the spectrum of taxanes with a hydrazine hydrate, thereby to convert into 10-deacetyl baccatin III some taxanes in said solution that are not 10-deacetyl baccatin III.Type: GrantFiled: March 16, 2000Date of Patent: August 28, 2001Assignee: NaPro BioTherapeutics, Inc.Inventors: James D. McChesney, Madhavi C. Chander, Douglas L. Rodenburg
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Patent number: 6143902Abstract: A chemic compound having the formula: ##STR1## wherein P.sub.1 is a hydroxyl protecting group, R.sub.1 is an alkyl group, an olefinic group, an aromatic group, Ph, PhCH.sub.2, an O-alkyl group, an O-olefinic group, an O-aromatic group, O--Ph, or O--CH.sub.2 Ph, and wherein Z is an N-imido group. In particular, P.sub.1 may be selected from the group consisting of benzyl, benzyloxymethyl and benzoyl, and Z may be a heterocyclic N-imido group, preferably having 5 to 7 atoms in the ring and alternatively substituted with at least one electron withdrawing group, preferably selected from the group consisting of a chloro group, a fluoro group and a nitro group. In particular, it is contemplated that Z may be succinimido, phthalimido, 5-norbornene-2,3-dicarboxyimido, maleimido and substituted derivatives thereof.Type: GrantFiled: June 21, 1999Date of Patent: November 7, 2000Assignee: NaPro BioTherapeutics, Inc.Inventors: Jan Zygmunt, James D. McChesney, Madhavi C. Chander
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Patent number: 6136999Abstract: A chemical compound having the formula: ##STR1## wherein P.sub.1 is a hydroxyl protecting group, R.sub.1 may be H or electron withdrawing group, R.sub.2 may be H or electron withdrawing group, R.sub.3 may be H or electron withdrawing group, R.sub.4 may be H or electron withdrawing group, R.sub.5 may be H or electron withdrawing group, R.sub.6 may be an alkyl group, an olefinic group, an aromatic group, Ph, PhCH.sub.2, an O-alkyl group, an O-olefinic group, an O-aromatic group, O--Ph, or O--CH.sub.2 Ph.Type: GrantFiled: June 21, 1999Date of Patent: October 24, 2000Assignee: NaPro BioTherapeutics, Inc.Inventors: Madhavi C. Chander, James D. McChesney, Jan Zygmunt
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Patent number: 6107497Abstract: C7, C10 di-CBZ 10-deacetyl baccatin III of the formula: ##STR1## provides an intermediate for the production of docetaxel. A method of producing this C7, C10 di-CBZ 10-deacetyl Baccatin III is provided. Here, 10-deacetyl Baccatin III is acylated with at least 1.5 equivalents of n-butyl lithium and at least 1.5 equivalents of benzyl chloroformate in tetrahydrofuran. The 10-deacetyl Baccatin III may first be dissolved in tetrahydrofuran after which the n-butyl lithium is added followed by the addition of the benzyl chloroformate. The reaction is preferably at a reduced temperature of less than -20.degree. C. The resulting solution may be quenched with ammonium chloride and reduced to residue. The residue may then be redissolved in an organic solvent, washed, dried and recrystallized to purify the compound.Type: GrantFiled: March 19, 1996Date of Patent: August 22, 2000Assignees: NaPro BioTherapeutics, Inc., Bryn Mawr CollegeInventors: Nicholas J. Sisti, Charles S. Swindell, Madhavi C. Chander
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Patent number: 6066749Abstract: A method of acylating C-2' O-protected-10-hydroxy taxol selectively at the C-10 hydroxyl position over the C-7 hydroxy position thereof to produce C-2' O-protected taxol is accomplished first by dissolving C-2' O-protected-10-hydroxy taxol in an acceptable ether solvent therefor, such as tetrahydrofuran, to form a first solution at a first temperature. The first solution is then cooled to a second temperature, and a lithium base, preferably n-butyl lithium, is added to form an intermediate compound having a lithium alkoxide at the C-10 position thereof. An acylating agent, such as acetyl chloride, is then added. The resulting solution may be quenched, for example with ammonium chloride, to eliminate excess of the acylating agent and the lithium base. The result is a solution containing C-2' O-protected taxol. This solution may then be washed, concentrated and purified. The present invention is also directed to C-10 lithium alkoxide intermediate compounds for the production of paclitaxel.Type: GrantFiled: May 1, 1998Date of Patent: May 23, 2000Assignee: NaPro BioTherapeutics, Inc.Inventors: Nicholas J. Sisti, Herbert R. Brinkman, James D. McChesney, Madhavi C. Chander, Xian Liang, Jan Zygmunt
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Patent number: 6048990Abstract: A method of acylating C-2' O-protected-10-hydroxy taxol selectively at the C-10 hydroxyl position over the C-7 hydroxy position thereof to produce C-2' O-protected taxol is accomplished first by dissolving C-2' O-protected-10-hydroxy taxol in an acceptable ether solvent therefor, such as tetrahydrofuran. A lithium salt, preferably lithium chloride, is added. A trialkylamine base or pyridine is next added, followed by the addition of an acylating agent, such as acetyl chloride. The resulting solution may be quenched, for example with ammonium chloride, to eliminate excess of the acylating agent. This solution may then be diluted with ethyl acetate to form an organic phase and an aqueous phase, with the organic phase being washed and thereafter reduced. Recrystallization and column chromatography may be employed to purify the C-2' O-protected taxol.Type: GrantFiled: May 1, 1998Date of Patent: April 11, 2000Assignee: NaPro BioTherapeutics, Inc.Inventors: Xian Liang, Jan Zygmunt, Nicholas J. Sisti, Madhavi C. Chander, Herbert R. Brinkman, James D. McChesney
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Patent number: 5948919Abstract: An efficient protocol for the synthesis of taxol, taxol analogs and their intermediates is described. The process incudes the attachment of the taxol A-ring side chain to baccatin III and for the synthesis of taxol and taxol analogs with variable A-ring side chain structures. A rapid and highly efficient esterification of O-protected isoserine and 3-phenylisoserine acids having N-benzyoloxycarbonyl groups to the C-13 hydroxyl of 7-O-protected baccatin III is followed by a deprotection-acylation sequence to make taxol, celphalomanninne and various analogs, including photoaffinity labeling candidates.Type: GrantFiled: June 7, 1995Date of Patent: September 7, 1999Assignees: NaPro BioTherapeutics, Inc., Bryn Mawr CollegeInventors: Nicholas J. Sisti, Charles S. Swindell, Madhavi C. Chander
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Patent number: 5914411Abstract: A method of acylating 10-deacetylbaccatin III at the C-10 position over the C-7 hydroxy position thereof to produce baccatin IIII is accomplished first by dissolving 10-deacetylbaccatin III in an acceptable ether solvent therefor, such as tetrahydrofuran. A lithium salt, preferably lithium chloride, is added. A trialkylamine base or pyridine is next added, followed by the addition of an acylating agent, such as acetyl chloride. The resulting solution may be quenched, for example with ammonium chloride, to eliminate excess of the acylating agent. The result is baccatin III in solution. This solution may then be diluted with ethyl acetate to form an organic phase and an aqueous phase, with the organic phase being washed and thereafter reduced. Recrystallization and column chromatography may be employed to purify the baccatin III.Type: GrantFiled: January 21, 1998Date of Patent: June 22, 1999Assignee: NaPro BioTherapeutics, Inc.Inventors: Nicholas J. Sisti, Jan Zygmunt, Herbert R. Brinkman, Madhavi C. Chander, Xian Liang, James D. McChesney
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Patent number: 5684175Abstract: The synthesis of paclitaxel obtained from the semi-synthesis of taxol using a protected baccatin III backbone which is esterified with a suitably protected side chain acid, thereby producing an intermediate which may be acylated and deprotected to produce paclitaxel.Type: GrantFiled: June 7, 1995Date of Patent: November 4, 1997Assignees: NaPro BioTherapeutics, Inc., Bryn Mawr CollegeInventors: Nicholas J. Sisti, Charles S. Swindell, Madhavi C. Chander
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Patent number: 5675025Abstract: An efficient protocol for the synthesis of taxol, taxol analogs and their intermediates is described. The process includes the attachment of the taxol A-ring side chain to baccatin III and for the synthesis of taxol and taxol analogs with variable A-ring side chain structures. A rapid and highly efficient esterification of O-protected isoserine and 3-phenylisoserine acids having N-benzyoloxycarbonyl groups to the C-13 hydroxyl of 7-O-protected baccatin III is followed by a deprotection-acylation sequence to make taxol, celphalomanninne and various analogs, including photoaffinity labeling candidates.Type: GrantFiled: June 7, 1995Date of Patent: October 7, 1997Assignee: NaPro BioTherapeutics, Inc.Inventors: Nicholas J. Sisti, Charles S. Swindell, Madhavi C. Chander