What are the patriarchs of the arabs in the Bible/Koran?

I read about Ishmael and Joktan (Qahtan). I also read that Abraham (Ibrahim) had a late concubine called Keturah (who was Japhetic according to some historians). Finally, some tribes in the south may have been Hamitic. So, arabs seem to be a mix of japhetic, hamitic and semitic, the last element is dominant of coure