Investigation of flow cytometry analysis linear and cyclic analogues of Longicalycinin A on cancerous cells HepG2 and HT-29

In this work, cyclic peptide analogues of Longicalycinin A, known as a natural cyclopeptide anticancer agent, have been designed and successfully synthesized by solid phase methodology of Fmoc / t-Bu. 2-chlorotrityl chloride resin (2-CTC) was used as solid support. The synthesized linear (Ot-Bu) Longicalycinin A analogues were cleavaged by the method of partial cleavage for the separation of the solid phase. Macrocyclization of linear (Ot-Bu) Longicalycinin A analogues were done by coupling reagent and then the final deprotection were done on cyclic (Ot-Bu) Longicalycinin A analogues by treatment of TFA 95% and scavengers to achieve cyclic Longicalycinin A analogues. In order to further examine structural basis of Longicalycinin A with the anticancer activity, some liner and cyclic Longicalycinin A peptide analogues were synthesized, using solid-phase peptide synthesis strategy, and their effects as anti-neoplastic agents were examined on cancer cell lines of HepG2 (Human Liver Cancer Cell Line) and HT-29 (Human Colorectal Adenocarcinoma Cell Line) using flow cytometry analysis. Flow cytometry analysis was determined by analytical DNA flow cytometry. HepG2 and HT-29 cells were harvested and adjusted to 104 cells/mL and then incubated for 6h with 10μg/mL of linear and cyclic peptides. The signals obtained in H-1 area mean that PI was able to enter the cells and bind to DNA and so apoptosis has occurred, whereas, the signals appeared in H-2 area indicate that the cancerous cells treated with linear and cyclic peptides remained intact and so no apoptosis has happened.

Investigation of flow cytometry analysis linear and cyclic analogues of Longicalycinin A on cancerous cells HepG2 and HT-29 Keywords:

Longicalycinin A , Macrocyclization , Anticancer , Apoptosis , 2-Cholorotrityl chloride resin