Provided herein are compounds, preparations and formulations comprising pyrazine derivatives having multiple poly(ethylene glycol) containing substituents. Many of the compounds disclosed herein are excretable by the renal system of a subject or patient and are useful for visualizing the renal system of a subject or patient. Upon excitation by electromagnetic radiation, a number of the compounds disclosed herein exhibit luminescence and are externally detectable when present in the body fluid of a patient or subject. Also provided herein are methods for visualizing the renal system of a subject or patient.