Red cell 2,3-BPG concentration is increased in anemia and in a variety of diseases in which there is chronic hypoxia This facilitates the delivery of O2 to the tissues by raising the PO2 at which O2 is released in peripheral capillaries.Inosine is a nucleoside involved in the formation of purines and a compound with possible roles in energy metabolism. It paicipates in oxygen metabolism and protein synthesis. Many of the effects attributed to inosine stem from its potential role in increasing levels of 2,3 DPG in red cellsHypoxanthin has no direct effect on 2,3 BPGRef: Ganong's Review of Medical Physiology Twenty-Third Edition Page No: 612, https://en.wikipedia.org/wiki/Inositol