Synthesis of cyclic peptide Longicalycinin A analogues by using solid resin

Th e aim of this study is designing of two cyclic penta peptide Longicalycinin A analogues which might have expected anticancer activity. In this work, Longicalycinin A and their two analogues, which have shown good toxicity against cell lines of HepG2 (human liver cancer cell line), HT-29 (human colorectal adenocarcinoma cell line) and A549 (adenocarcinomic human alveolar basal epithelial cells) using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT assay). 2-chlorotritylchloride resin (2-CTC) was used as solid support and a suitable resin. 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 trifluoroacetic acid 95% and scavengers. Th e synthesized cyclic Longicalycinin A analogues were characterized by using different methods such as, LC-MS and FT-IR.