Nicolae Constantin Paulesco was a renowned Romanian experimental physiologist, professor of medicine, and politician, most famous for his work on diabetes, including patenting pancreine, a bovine pancreatic extract in salted water, after the removal of impurities with hydrochloric acid and sodium hydroxide and contains insulin. His research interest was on the active substance from the pancreas which the German physiologist and pathologist Oskar Minkowski and the German physician Joseph von Mering had suggested could be used to treat diabetes.

In 1916, Paulesco succeeded in developing an aqueous pancreatic extract which, when injected into a diabetic dog, proved to have a normalizing effect on blood sugar levels. He had published several papers titled 'The effect of the pancreatic extract injected into a diabetic animal by way of the blood, The influence of the time elapsed from the intravenous pancreatic injection into a diabetic animal and the effect of the pancreatic extract injected into a normal animal by way of the blood' at the Romanian Section of the Society of Biology.

As his attempts to purify the extract pancreine was successful partially only and caused irritations in dogs and humans upon administration, and by the meantime, Banting and Best came out with the extraction of insulin successfully Paulesco was denied the prestigious Nobel Prize for the discovery of insulin. Many years later, in a recent private communication Professor Tiselius, head of the Nobel Institute, has expressed his personal opinion that Paulesco was equally worthy of the award in 1923.

Paulesco died in 1931 in Bucharest. In 1993, the Institute of Diabetes, Nutrition and Metabolic Diseases in Bucharest was named in his honour (Institutul de Diabet, Nutriţie şi Boli Metabolice "N. C. Paulescu") but later on renamed.