Thesis (M.Sc.)--Chulalongkorn University, 2007

Thai bitter gourd (Momordica charantia Linn.) has been used as vegetable as well as medicine. It has been used in traditional Thai medicine as bitter tonic, antipyretic, cholagogue, antirheumatic, antheminthic and laxative. The present study aimed to characterize components and bioactivities (hemagglutination and alpha-glucosidase inhibition) of proteins from Thai bitter gourd fruit pulp. Crude protein was extracted by phosphate buffer and fractional precipitation with ammonium sulfate in early step in purification step and separated by anion-exchange column chromatography. Afterwards, the protein fractions were tested for bioactivity, hemagglutination and alpha-glucosidase inhibition. Crude protein (40U, 40B5, 40B10, 40B20, 40B30, 40B50, 40B100, 80U, 100U and 100B100) showed hemagglutinating activity with rabbit red blood cell. Highest specific hemagglutinating activity found at 40B5 (400 U/mg protein). From peptides mass mapping by MALDI-TOF MS and amino acid sequence database searching, 40B5 was similar to partial amino acid sequence of OSJNBa0084N21.4 protein from Oryza sativa Linn. alpha-Glucosidase inhibitions were found in 20U, 40B5, 40B50, 60U, 80U, 80B10, 80B20, 80B50, 100U and 100B100. 100B100 showed highest alpha-glucosidase inhibition with IC[subscript 50]The amino acid sequence from peptide mass mapping database searching from 100B100 were similar to partial amino acid sequence of hypothetical protein from Vitis vinifera Linn.