A high throughput screen for 17 Dermorphin peptides in equine and human urine and equine plasma

Abstract

The Dermorphins are a family of peptides that act as potent agonists of the opioid μ receptor. Originally identified as a seven amino acid peptide on the skin of the South American Phyllomedusa frog, peptide chemists have since developed a large number of Dermorphin variants, many with superior opioid activity to the original peptide. Dermorphins are unique among the peptide opioid agonists as they appear to have a limited ability to cross the blood brain barrier, producing effects on both the central and peripheral nervous systems. It is this ability of Dermorphins to provide central anaesthesia after intravenous or subcutaneous administration that allows their use as analogues of the opioid class of drugs. Recently, illicit use of the Dermorphin peptide in the racing industry has shown the need for an analytical method to control the use of these peptides. We present a high-throughput liquid chromatography-tandem mass spectrometry screen for 17 Dermorphin peptides in equine urine and plasma with limits of detection down to 5 pg/mL. The peptide extraction technique is also suitable for use in human urine.

A high‐throughput LC‐MS/MS screen for GHRP in equine and human urine, featuring peptide derivatization for improved chromatography

“…Urine samples were prepared as described in Steel et al, [15] with the addition of an acetylation step. Urine (2 mL) was acidified in a 12 x 75 mm glass tube by the addition of 200 μL of 100% w/v TCA.…”

“…To meet these demands, solid-phase extraction (SPE) followed by liquid chromatography-mass spectrometry (LC-MS) analysis has become the method of choice. [15] A final challenge for the development of a high-throughput GHRP screen is the ability to perform rapid chromatography of the basic GHRP peptides. [10][11][12] However, the detection windows for GHRP in plasma may be as short as 2 h, [13] significantly reducing the probability of detecting a GHRP administration.…”

Chemical space screening around Phe3 in opioid peptides: Modulating µ versus δ agonism by Suzuki-Miyaura cross-couplings

“…12–14 Compared to morphine, dermorphin was shown to possess higher antinociceptive efficacy with decreased adverse effects. 15 SAR studies indicated the N -terminal tetrapeptide to be the minimal sequence required for potent opioid responses.…”

The detection of a synthetic Interleukin‐1 receptor antagonist peptide in a seized product from a racing stable

“…Previous methods developed for detecting peptides in urine by LC‐MS were based on cation‐exchange SPE and were optimized for basic peptides . In comparison, the IL‐1RA peptide is acidic and is not retained on cation‐exchange SPE columns by ionic interactions.…”