Synthesis of Mono-PEGylated Growth Hormone Releasing Peptide-2 and Investigation of its Biological Activity

Abstract

The purpose of this study was to investigate an efficient synthetic route to the mono-PEGylated growth hormone releasing peptide-2 (GHRP-2) and its biological activity in vivo. The commercially available key PEGylating reagent, mPEG-NHS ester, was successfully utilized to the synthesis of mono-PEGylated GHRP-2, during which the PEGylation profiles of GHRP-2 were monitored by high-performance liquid chromatography (HPLC). The product was purified by cation exchange chromatography, and its biological activity was conducted in rats. The desired mono-PEGylated GHRP-2 as the major product was readily obtained in anhydrous aprotic solvent, such as dimethyl formamide (DMF) and dimethylsulfoxide (DMSO), when the molar ratio of mPEG-NHS ester to GHRP-2 was fixed to be 0.8:1. The products were characterized by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. The evaluation of the biological activity for the products showed that the mono-PEGylated GHRP-2 gave a more stable activity than GHRP-2, suggesting that PEGylation led to the increase in the half-life of GHRP-2 in plasma without greatly impairing the biological activity. PEGylation of the GHRP-2 is a good choice for the development of the GHRP-2 applications.

Annual banned‐substance review: analytical approaches in human sports drug testing

“…Besides GHRP‐2 (pralmorelin), no ghrelin mimetic has yet received clinical approval; however, various drug candidates have been reported in the past and research into potential new drug entities or established compounds with modified physico‐chemical properties has continued. Among the new additions to the GHRP portfolio, PEGylated GHRP‐2 (as agonist) and PEGylated as well as palmitoylated ghrelin receptor inverse agonists were described, pointing into a direction that might necessitate expanded doping control analytical approaches in the future. Currently, predominantly findings of GHRP‐2 and GHRP‐6 in seized material as well as routine sports drug testing samples have been mentioned, with urinary concentrations necessitating LODs for the intact drug and diagnostic metabolites in the low pg/mL range.…”

“…- [131,132,136,[138][139][140][141][142]144,[146][147][148][149] - [24,[125][126][127][128][129][130][132][133][134][135]137,143,145] S3 Beta-2-Agonists - [159][160][161][162][163] - [24,[150][151][152][153][154][155][156][157][158] S4 Hormone and metabolic modulators 1 Aromatase inhibitors [164] - [164] [ 24,165] 2 Selective estrogen receptor modulators (SERMs) - [167,169,170] - [24,…”