Peptides from two sanguinovorous leeches analyzed by ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometric detector

Background: Hirudo nipponica Whitman and Poecilobdella manillensis Lesson fall into the family of Hirudinidae Whitman, both of them are sanguinovorous leeches and used a anticoagulant medicines in China. Their medicinal parts are the dried bodies. However, the peptides in the dried body of the two leeches have not been very clear up to now.

Objective: To analyze the peptides from two sanguinovorous leeches, H. nipponica and P. manillensis.

Materials and methods: In this article it is reported that the peptides were obtained from anticoagulant active extracted parts of dried bodies of the two leeches and their molecular weights were analyzed by ultra-performance liquid chromatography with electrospray ionization quadrupole time-of-flight mass spectrometry mass spectrometric detector online.

Results: Three peptide components were identified from H. nipponica with their molecular weight separately 14998, 15988, and 15956, six peptide components were identified from P. manillensis with molecular weight 9590, 13642, 14998, 17631, 15988, and 16567. Two of peptides from P. manillensis have the same molecular weight 14998 and 15988 as that in H. nipponica.

Conclusion: And the two peptides are the main peaks in the base peak ion chromatogram because they occupied a large ratio of total base peak area. Hence the composition of the extracted active part of the two leeches are very close, difference is in that the extract of P. manillensis has more small peptide peaks, but the extract of H. nipponica has not. Furthermore, the tryptic digestion hydrolysates of the extracted active part of each sample were analyzed and the results showed that there were four peaks which only exist in P. manillensis, but not in Hirudo nipponia. They may be the identified peak between the two leeches. This work support the viewpoint that P. manillensis can be used as a medicinal leech as H. nipponia and these peptide components of dried bodies of the two species leeches are a basis for their chemical identification and further investigations in active action.