An evaluation study on screening, partial purification, and characterization of proteins and antioxidant peptides from two varieties of Clitoria Ternatea.

This study focused on the unexplored bioactive proteins derived from the flower of Clitoria ternatea. The profiling of blue and white C. ternatea flowers was compared. After extraction, the samples underwent ultrafiltration and the isolation of the protein peptides was done by using four different buffers. The highest yield was found in the case of phosphate buffered-based extracts in blue C. ternatea flower. The single HPLC peak at 220 nm with a high area percentage confirmed the presence of peptides in all the 3 kDa filtrates of C. ternatea. These 3 kDa filtrates were concentrated by using a C-18 zip tip method, with alpha-cyano-4-hydroxycinnamic acid as a substrate for MALDI-TOF-MS-based peptide mass analysis. To determine the antioxidant activity of the peptides, four different assays including DPPH, ABTS, FRAP and NOS were used and it was observed that the blue C. ternatea flower exhibited the potential activity when compared to the white C. ternatea flower. Among all, the phosphate buffer filtrate exhibited the highest antioxidant activity. The binding affinity of the identified protein peptides APCPNR, LGLFR, LIPQE and SISWSS from blue and white flower were evaluated against amyloid beta (Aβ) and acetylcholinesterase (AChE) targets of Alzheimer's disease by in silico analysis.