Patents by Inventor Anand Natrajan

Anand Natrajan 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).

  • Publication number: 20050221390
    Abstract: The present invention relates to hydrophilic, high quantum yield acridinium compounds. It has been discovered that the placement of electron-donating groups in the acridinium ring system increases the amount of light that is emitted by the corresponding acridinium compound when its chemiluminescence is triggered by alkaline peroxide. More specifically, it has been found that the placement of one or two hydrophilic, alkoxy groups at the C-2 and/or C-7 position of the acridinium ring system of acridinium compounds increases their quantum yield and enhances the aqueous solubility of these compounds. The present hydrophilic, high quantum yield, acridinium compounds are useful chemiluminescent labels for improving the sensitivity of immunoassays.
    Type: Application
    Filed: June 2, 2005
    Publication date: October 6, 2005
    Applicant: Bayer HealthCare LLC
    Inventors: Anand Natrajan, Qingping Jiang, David Sharpe, James Costello
  • Publication number: 20050032147
    Abstract: A chemiluminescent substrate of a hydrolytic enzyme having the following general Formula I is disclosed, as follows: Lumi-M-P??Formula I where “Lumi” is a chemiluminescent moiety capable of producing light (a) by itself, (b) with MP attached and (c) with M attached. Examples of Lumi include chemiluminescent acridinium compounds, benzacridinium compounds, quinolinium compounds, isoquinolinium compounds, phenanthridinium compounds, and lucigenin compounds, spiroacridan compounds, luminol compounds and isoluminol compounds. M is a multivalent heteroatom having at least one lone pair of electrons selected from oxygen, nitrogen and sulfur, directly attached to the light emitting moiety of Lumi at one end and to P at the other end. P is a group that can be readily removed by hydrolytic enzymes. An enzymatic reaction utilizing the above compound is the following: where HE is a hydrolytic enzyme. Lumi-M is a chemiluminescent product having physical and/or chemical properties different from those of Lumi-M-P.
    Type: Application
    Filed: August 27, 2004
    Publication date: February 10, 2005
    Inventors: Qingping Jiang, Anand Natrajan, David Sharpe, Wen-Jee Wong, Say-Jong Law
  • Patent number: 6783948
    Abstract: A chemiluminescent substrate of hydrolytic enzyme having the following general Formula I, as follows: Lumi-M-P  Formula I where “Lumi” is a chemiluminescent moiety capable of producing light (a) by itself, (b) with MP attached and (c) with M attached. Examples of Lumi include chemiluminescent acridinium compounds, benzacridinium compounds, quinolinium compounds, isoquinolinium compounds, phenanthridinium compounds, and lucigenin compounds, spiroacridan compounds, luminol compounds and isoluminol compounds. M is a multivalent heteroatom having at least one lone pair of electrons selected from oxygen, nitrogen and sulfur, directly attached to the light emitting moiety of Lumi at one end and to P at the other end. P it a group that can be readily removed by hydrolytic enzymes.
    Type: Grant
    Filed: July 27, 2000
    Date of Patent: August 31, 2004
    Assignee: Bayer Corporation
    Inventors: Qingping Jiang, Anand Natrajan, David J. Sharpe, Wen-Jee Wong, Say-Jong Law
  • Publication number: 20040063147
    Abstract: Chemiluminescent acridinium compounds are used in homogeneous assays to determine the concentration of an analyte in a sample without strong acid or strong base treatment. The chemiluminescent acridinium compounds include acridinium esters with electron donating functional groups at the C2 and/or C7 position on the acridinium nucleus to inhibit pseudo-base formation, or acridinium sulfonamides with or without electron donating functional groups at the C2 and/or C7 position on the acridinium nucleus.
    Type: Application
    Filed: September 27, 2002
    Publication date: April 1, 2004
    Applicant: BAYER CORPORATION
    Inventors: Anand Natrajan, Todd Sells, Hartmut Schroeder, Guohan Yang, David Sharpe, Qingping Jiang, Hana Lukinsky, Say-Jong Law
  • Patent number: 6673560
    Abstract: The present invention discloses a method for the measurement of hydride using a chemiluminescent compound. The preferred chemiluminescent molecule is an acridinium compound. The source of hydride for the reduction of acridinium compound may be of chemical or biochemical origin, or the result of enzymatic catalysis. The chemical source of hydride, for example, might be metal hydrides, such as NaBH4. A biochemical source of hydride might be that derived from NADH, or NADPH, while an enzymatic source would be the class of oxidoreductases termed dehydrogenases which convert NADH or NADPH from NAD or NADP. There are numerous potential applications for acridinium compounds as chemiluminescent indicators of hydride. Any applied tests or diagnostic assays, in which hydride is either present at the onset of or generated through the course of a reaction, would benefit from the present invention.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: January 6, 2004
    Assignee: Bayer Corporation
    Inventors: David Sharpe, Anand Natrajan, Qingping Jiang, George Parsons, Say-Jong Law
  • Patent number: 6664043
    Abstract: The present invention is generally directed to detectable chemiluminescent acridinium ester labels having hydrophilic modifiers; to compositions, complexes and/or conjugates which include such labels; and to processes for performing bioanalytical assays for target analytes which use such labels. Assays for folate, theophylline, and tobramycin (using such labels with hydrophilic modifiers such as nonionic polyethylene glycol and polyionic spermine disulfonate and polyionic spermine dicarboxylate) are described in detail.
    Type: Grant
    Filed: July 3, 2001
    Date of Patent: December 16, 2003
    Assignee: Bayer Corporation
    Inventors: Anand Natrajan, David Sharpe, Qingping Jiang
  • Publication number: 20030045716
    Abstract: The present invention is generally directed to detectable chemiluminescent acridinium ester labels having hydrophilic modifiers; to compositions, complexes and/or conjugates which include such labels; and to processes for performing bioanalytical assays for target analytes which use such labels. Assays for folate, theophylline, and tobramycin (using such labels with hydrophilic modifiers such as nonionic polyethylene glycol and polyionic spermine disulfonate and polyionic spermine dicarboxylate) are described in detail.
    Type: Application
    Filed: July 3, 2001
    Publication date: March 6, 2003
    Inventors: Anand Natrajan, David Sharpe, Qingping Jiang
  • Publication number: 20020076823
    Abstract: Our results thus identify two sets of necessary and sufficient criteria for observing long-wavelength emission from acridinium compounds:
    Type: Application
    Filed: December 6, 2001
    Publication date: June 20, 2002
    Applicant: BAYER CORPORATION
    Inventors: Anand Natrajan, Qingping Jiang, David Sharpe, Say-Jong Law
  • Patent number: 6355803
    Abstract: This application relates to long-wavelength acridinium compounds having electron-donating groups, which may either be: (a) Part of an extended conjugation system attached by appropriate functional groups to the acridinium nucleus, with coplanarity of the attached functional group and the acridone moiety during light emission (geometry requirement), said functional group consisting of at least one aromatic ring and one electron-donating atom or group with an extra pair of electrons which can readily delocalize into the extended &pgr; system to which the heteroatom is directly attached or built into, and establish stable extended resonance with the electron-withdrawing carbonyl moiety of the light emitting acridone.
    Type: Grant
    Filed: August 10, 1999
    Date of Patent: March 12, 2002
    Assignee: Bayer Corporation
    Inventors: Anand Natrajan, Qingping Jiang, David Sharpe, Say-Jong Law
  • Patent number: 6165800
    Abstract: A new class of chemiluminescent acridinium or benzacridinium compounds is disclosed by virtue of forming an intramolecular energy transfer conjugate (ETC) between the acridinium or benzacridinium compound and a luminophore. A method of extending the emission wavelengths of acridinium or benzacridinium esters in order to further reduce or eliminate the emission spectral overlap between the parent polysubstituted aryl Acridinium Esters (DMAE) and Benzacridinium Esters (LEAE) is disclosed. The ETC's retain the unique desired properties of acridinium or benzacridinium compounds including complete light emission in very short period of time, monophasic emission spectrum, simplicity of triggering mechanism, ability of labeling the biological molecules of interest to form a tracer, and good stability. Additionally, the range of the emission spectrum of an acridinium or benzacridinium compound can now be shifted at will and at longer leap through the choice of a luminophore as the integral part of an ETC molecule.
    Type: Grant
    Filed: May 27, 1998
    Date of Patent: December 26, 2000
    Assignee: Bayer Corporation
    Inventors: Qingping Jiang, Jun Xi, Anand Natrajan, David Sharpe, Marcus Baumann, Rolf Hilfiker, Erika Schmidt, Paul Senn, Fritz Thommen, Adrian Waldner, Alex Alder, Say-Jong Law
  • Patent number: 5656426
    Abstract: Novel acridinium esters that are useful, either alone or when incorporated into liposomes, as chemiluminescent agents in binding assays (e.g., immunoassays and gene probe assays) with improved-sensitivity are disclosed. In addition, the synthesis of these esters and their use in assays for detecting an analyte is described. In particular, assays for testosterone and the Rubella virus are disclosed.
    Type: Grant
    Filed: April 8, 1994
    Date of Patent: August 12, 1997
    Assignee: Chiron Diagnostics Corporation
    Inventors: Say-Jong Law, Chariklia Sotiriou-Leventis, Anand Natrajan, Qingping Jiang, Peter B. Connolly, John P. Kilroy, Constance R. McCudden, Stephen M. Tirrell