Modification of the haemoglobin oxygen dissociation curve in whole blood by a compound with dual action

2-Ethoxy-6-(5-tetrazolyl)xanthone reduces the oxygen affinity of blood by two mechanisms; firstly, by a direct effect on the haemoglobin molecule and secondly by maintaining levels of 2,3-diphosphoglycerate (DPG) in stored blood. This compound thus has potential as a blood storage additive which will improve the oxygen delivery of stored blood.