Complex sentence: Methyldihydromorphine is related to heterocodeine and is not a synonym for dihydrocodeine, and its structure suggests that it is six to nine times stronger than morphine and 72 times stronger than dihydrocodeine.
Split into simpler sentences: Methyldihydromorphine is related to heterocodeine and is not a synonym for dihydrocodeine. Its structure suggests that it is six to nine times stronger than morphine and 72 times stronger than dihydrocodeine.