Apiin is a beta-D-glucoside having a beta-D-apiosyl residue at the 2-position and a 5,4'-dihydroxyflavon-7-yl moiety at the anomeric position. It has a role as an EC 3.2.1.18 (exo-alpha-sialidase) inhibitor and a plant metabolite. It is a beta-D-glucoside, a dihydroxyflavone and a glycosyloxyflavone. It is functionally related to an apigenin. It is a conjugate acid of an apiin(1-). Apiin as a reducing agent, used in biological synthesis of silver and gold nanoparticles. Apiin has anti-inflammatory properties, it has inhibitory activity in-vitro on iNOS expression and nitrite production when added before LPS stimulation in the medium of J774.A1 cells. Apiin is an iNOS inhibitor of flavonoid glycosides. Apiin can inhibit the expression of inducible nitric oxide synthase in activated macrophages. Apiin has anti-inflammatory activity.