It only gets boiled down to pure sugar. You boil off or break down a lot of the aromatics and volatiles in the original sap to make syrup. It gets processed by boiling to concentrate the sugar and reduce the presence of the rest of what the tree was living on. Maple sap does not become “pure sugar” (maple syrup) until after it gets the good stuff processed out.

This Cleveland Health Clinic page on maple sap mentions the presence of abscisic acid, a plant hormone with anti-diabetic properties, and polyphenols that help you manage inflammation.