Assay of 6‐thioguanine in human plasma.

Abstract

1. A fluorimetric method has been developed for measuring therapeutic concentrations of 6‐thioguanine in human plasma. The drug was measured as an oxidized derivative, guanine 6‐sulphonate. 2. 6‐thioguanine was extracted from plasma by a novel procedure which isolated the drug from an interfering plasma components. This method involved the formation of the thioguanine phenyl mercury derivative in alkaline plasma and its extraction into toluene. The free drug was released by back‐extraction into hydrochloric acid. 3. The assay is specific and shows a limit of sensitivity of 5 ng/ml. This was shown to be adequate for measuring plasma concentrations of 6‐thioguanine after the administration of a 160 mg dose in a patient with leukaemia.

New nanomedicine approaches using gold–thioguanine nanoconjugates as metallo-ligands

“…It is well known that, TG can emit at 410 nm when excited at 330 nm. 37 This phenomenon clearly suggests that the Eu 3+ is attached to TG through nitrogen centers of base. One possible explanation of quenching Eu 3+ emission in presence of AuNP-TG is that there is an energy transfer from the long-lived excited sate of Eu 3+ (donor) to the short-lived excited state of TG (acceptor).…”

6-Mercaptopurine: apparent lack of relation between prescribed dose and biological effect in children with leukaemia

“…Assay of RBC 6-TG nucleotide used a technique originally developed to study azathioprine metabolism in renal-transplant recipients, and will be published in (1980), and hyprolysed to the parent purine, 6-thioguanine, which was then assayed fluorimetrically (Dooley & Maddocks, 1980). The amount of 6-TG nucleotide was stated as ng of free 6-TG released on hydrolysis of the nucleotide.…”