Complex sentence: Since ancient times, myrrh has been valued for its fragrance, its medicinal qualities as a wound dressing and an aromatic stomatic and for the ancient Egyptians as the principal ingredient used in the embalming of mummies.
Split into simpler sentences: Since ancient times, myrrh has been valued for its fragrance and its medicinal qualities as an aromatic wound dressing. It was used by the ancient Egyptians as the principal ingredient for the embalming of mummies.