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 increasing a density of carboxylic acids on a surface of a carbon nanoparticle is disclosed. The method includes contacting an oxygen-containing functional group on a surface of a carbon nanoparticle with a reducing agent to provide a hydroxyl group; reacting the hydroxyl group with a diazoacetate ester in the presence of a transition metal catalyst to provide an ester, the diazoacetate ester having the structure wherein R is a C1-8 hydrocarbyl, preferably tert-butyl, methyl, ethyl, isopropyl, allyl, benzyl, pentafluorophenyl, or N-succinimidyl; and cleaving the ester to provide a carboxylic acid group. Surface-functionalized carbon nanoparticles made by the method are also disclosed.

Abstract: A method of increasing a density of carboxylic acids on a surface of a carbon nanoparticle is disclosed. The method includes contacting an oxygen-containing functional group on a surface of a carbon nanoparticle with a reducing agent to provide a hydroxyl group; reacting the hydroxyl group with a diazoacetate ester in the presence of a transition metal catalyst to provide an ester, the diazoacetate ester having the structure wherein R is a C1-8 hydrocarbyl, preferably tert-butyl, methyl, ethyl, isopropyl, allyl, benzyl, pentafluorophenyl, or N-succinimidyl; and cleaving the ester to provide a carboxylic acid group. Surface-functionalized carbon nanoparticles made by the method are also disclosed.