Direct arterial injection of hyperpolarized C-labeled substrates into rat tumors for rapid MR detection of metabolism with minimal substrate dilution.

Purpose: A rat model was developed to enable direct administration of hyperpolarized C-labeled molecules into a tumor-supplying artery for magnetic resonance spectroscopy (MRS) studies of tumor metabolism.

Methods: Rat P22 sarcomas were implanted into the right inguinal fat pad of BDIX rats such that the developing tumors received their principle blood supply directly from the right superior epigastric artery. Hyperpolarized C-molecules were either infused directly to the tumor through the epigastric artery or systemically through the contralateral femoral vein.

Enantioselective preparation of P-chiral phosphine oxides.

A highly efficient chiral auxiliary-based strategy for the asymmetric synthesis of P-chiral phosphine oxides in >98:2 er has been developed. The methodology involves the highly stereoselective formation of P-chiral oxazolidinones that then undergo displacement with a variety of Grignard reagents to prepare the desired phosphine oxides.