An undescribed tricyclic spiroketal compound clathriketal was purified from the solvent extract of the Microcionidae sponge Clathria prolifera, and was characterised as 7-(hydroxymethyl)-13-methoxy-3,11-dimethyl-4-oxo-octahydrospiro[chromene-9,13-pyran]-11-yl propionate by spectroscopic experiments. Clathriketal exhibited significant anti-hyperglycemic property by attenuating serine protease dipeptidyl peptidase-IV (IC50 0.37 mM), and its activity was comparable with the standard diprotin A (IC50 0.31 mM). The spiroketal also exhibited significant inhibitory potentials against carbolytic enzymes α-glucosidase (IC50 0.43 mM) and α-amylase (IC50 0.41 mM). Superior antioxidant properties of clathriketal against the oxidants, 2, 2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid and 2, 2-diphenyl-1-picrylhydrazyl (IC50 ∼1.2 mM) also reinforced its promising anti-hyperglycemic activity. Considerably greater topological surface area (91.29) coupled with lesser steric parameters of clathriketal, as elucidated from the structure-activity relationship analyses could further ascribe the improved ligand-receptor interactions resulting in its prospective anti-hyperglycemic activity. Molecular docking analysis of clathriketal with dipeptidyl peptidase-IV recorded lesser binding energy (–9.63 kcal/mol), which further corroborated its prospective antihyperglycemic activity.