hexapeptide

The story

1. Proto-Indo-European*swéḱs
2. Proto-Hellenic*hwéks
3. Ancient Greekἕξ (héx)
4. Ancient Greekἑξα- (hexa-)
5. Latinhexa-
6. Englishhexa-
7. Proto-Indo-European*pekʷ-
8. Proto-Indo-European*pékʷ-ye-
9. Proto-Hellenic*pét͏̌t͏̌ō
10. Ancient Greekπέσσω (péssō)bf.
11. Ancient Greekπέπτω (péptō)
12. Ancient Greekπεπτόν (peptón)
13. GermanPepton
14. Englishpeptone
15. Proto-Indo-European*dʰeh₁-
16. GermanPepton
17. GermanPeptid
18. Englishpeptide
19. English todayhexapeptide

From hexa- + peptide.