The molecular details of the generation of 1,5-aF from glycogen have not been worked out, so that process is not annotated here. Studies of pig liver have allowed the identification of AKR1E2 as the enzyme that catalyzes the conversion of 1,5-aF to 1,5-aG and the biochemistry of this reaction has been worked out in detail (Sakuma et al. 1998). More limited studies have identified the mouse (Sakuma & Kubota 2008) and human (Azuma et al. 2004; Nishinaka et al. 2003) homologues of the pig enzyme, allowing annotation of a human reaction to convert 1,5-aF to 1,5-aG.

Much of the 1,5-aG found in plasma appears to derive from dietary sources, and there is no evidence that the molecule is metabolized further (Yamanouichi et al. 1992), so the normal physiological role of this pathway is unclear. Tong et al. (2022) have demonstrated, however, that 1,5-aG binds the S2 subunit of SARS-CoV-2 spike protein and virus treated with 1,5-aG shows a reduced ability to fuse with host cell membranes. This observation, and the subnormal levels of 1,5-aG observed in people with diabetes, suggests a possible molecular basis for the increased susceptibility to severe COVID-19 disease in such people.