Abstract: Disclosed are compounds of Formula (I), pharmaceutically acceptable salts thereof, and methods of preparation thereof, wherein R1, Xa, Xb, Xc, and Xd are as described in the specification. Further disclosed is an isotopic mixture of a compound of Formula (I), as well as a pharmaceutical composition containing a hyperpolarized compound of Formula (I). Also disclosed is a method of diagnosing or monitoring a patient suffering from cancer, the method including administering a pharmaceutical composition comprising an effective amount of a hyperpolarized ketoglutarate compound or a pharmaceutically acceptable salt thereof, and measuring the hyperpolarization of a compound of interest in the patient. Further disclosed is a method of preparing hyperpolarized ketoglutarate compounds for use in the above methods.

Abstract: A compound of the Formula I or a pharmaceutically acceptable salt thereof, wherein R1, Ca, Cb, Cd, and n are the same as described in the specification. Disclosed is a method of diagnosing or monitoring a patient suffering from cancer, the method comprising: administering a pharmaceutical composition comprising an effective amount of an active agent, wherein the active agent is the compound of Formula I, a pharmaceutically acceptable salt of any of the foregoing thereof, or a combination thereof, together with a pharmaceutically acceptable carrier to the patient and diagnosing or monitoring the patient by hyperpolarized 13C-MRI. Also disclosed is a method of synthesizing 1-13C-5-12C-diacid.

Abstract: A method of diagnosing or monitoring a patient suffering from cancer, the method comprising: administering a pharmaceutical composition comprising an effective amount of an active agent, wherein the active agent is [1-13C] N-acetyl cysteine, a deuterated derivative thereof, a pharmaceutically acceptable salt of any of the foregoing thereof, or a combination thereof, together with a pharmaceutically acceptable carrier to the patient; and diagnosing or monitoring the patient by hyperpolarized 13C-MRI. Also disclosed is a method of synthesizing [1-13C] N-acetyl cysteine or a deuterated derivative thereof.