Graphical abstract Highlights • Five novel and rare cadinane-type sesquiterpene glycosides were identified. • This is the first report on the cadinane-type sesquiterpene glycosides in Cornus. • All the isolates possess potent α -glucosidase inhibitory activities except for 3. • The new compounds may extend the chemical diversity of cadinane sesquiterpenes. Abstract Five novel and rare cadinane-type sesquiterpene glycosides, cornucadinoside A-E (1 – 5) were isolated from water extract of the fruit of Cornus officinalis Sieb. et Zuuc.. The new chemical structures, together with their absolute configurations, were elucidated on the basis of extensive spectroscopic analysis, including a comparison of their experimental and calculated electronic circular dichroism (ECD) spectra. Their structures, which possess a naphthalene skeleton, are the first report on the occurrence of cadinane sesquiterpene glycosides in Cornus. Additionally, all the compounds exhibited marked α -glucosidase inhibitory activity except for 3 in vitro. [ABSTRACT FROM AUTHOR]