original: However, this list contains substances which may have synthetic origins.
simplifications: This list contains substances which may have man made origins. But, the list has items that may not have been made naturally. This list has substances that may have been synthetically created. The list contains substances that may have unnatural origins. But, there may be substances on this list that come from synthetic sources. However, this list contains substances which may be synthetic. But, this list contains substances which may be artificial. This list contains substances which may have aritficial origins. Still, this list has materials which may have fake beginnings. However, this list contains substances which may have synthetic origins.