Phosphate-based 2,3-DPG mimetics as Hemoglobin allosteric modulators with potent anti-hypoxic activity

Area of Science:

• Pharmacology
• Medicinal Chemistry
• Physiology

Background:

• High-altitude hypoxia impairs tissue oxygen delivery, leading to acute mountain sickness.
• Current treatments for altitude-related illnesses are limited.

Purpose of the Study:

• To design, synthesize, and evaluate novel 2,3-diphosphoglycerate (2,3-DPG) mimetics as a therapeutic strategy for high-altitude hypoxia.
• To improve metabolic stability and membrane permeability of 2,3-DPG mimetics through bioisosteric replacement and esterification.

Main Methods:

• Synthesis and characterization of seven novel phosphate ester and amino acid-based compounds with PN and PS bonds.
• Pharmacological evaluation in normobaric hypoxia models, hypobaric chamber simulations (7000m), and a high-altitude field study (4010m).
• Assessment of survival rates, hemoglobin P50 (Hb P50), oxidative stress markers (GSH), inflammatory cytokines (IL-6, TNF-α), and histopathological damage.

Main Results:

• Ethyl ester derivatives 1e, 2e, 2f, and 2h significantly prolonged survival in normobaric hypoxia.
• Compounds 2f and 2h demonstrated highest efficacy, prolonging survival by up to 38.97%.
• In hypobaric conditions, 2f and 2h increased Hb P50 by up to 35%, improving oxygen dissociation and tissue oxygenation.
• In field studies, 1e and 2e attenuated oxidative stress, reduced inflammation, and alleviated tissue damage.

Conclusions:

• Compounds 2f and 2h are the first phosphate-based allosteric modulators of hemoglobin (Hb) that effectively enhance tissue oxygenation under extreme hypoxia.
• These novel 2,3-DPG mimetics offer a promising therapeutic approach for preventing and treating high-altitude illnesses.