a purine D-ribonucleoside + H2O <=> a purine nucleobase + D-ribose
a purine d-ribonucleoside + h2o <=> a purine nucleobase + d-ribose
a purine D-ribonucleoside + H2O <=> a purine nucleobase + D-ribose
a purine d-ribonucleoside + h2o <=> a purine nucleobase + d-ribose