Main pancreatic duct is derived from:

The pancreas develops from the two endodermal buds, dorsal and ventral, that arise from the pa of the gut that later forms the second pa of the duodenum. The ventral bud forms the lower pa of the head, and the uncinate process of the pancreas, while the upper pa of the head, the body and the tail are formed from the dorsal bud. The main pancreatic duct is formed, in its distal pa, by the duct of dorsal bud, and in its proximal pa by the duct of the ventral bud. The islets of Langerhans are also derived from the primitive duct system. Ref: Textbook of Human Embryology, 6th Ed, Page 184.