Abstract: The nutrients components of the peduncle of Alisma orientale (Sam.) Juzep.were determined using national standard method and its nutritional value of protein was evaluated by methods of chemical score and ratio coefficient of amino acid.In addition,the inhibitory activity of its crude extracts on α-glucosidase was investigated. The results showed that the contents (per 100 g of dry sample) of crude protein,crude fat,total dietary fiber,ash,polysaccharide,reducing sugar,vitamin C and carotene were 26.10,2.20,27.56,8.70,4.22,4.87 g,406.30 mg and 380.00 μg,respectively.The ratio of essential amino acid to total amino acid (EAA/TAA) was 39.54% and the ratio of essential amino acid to not essential amino acid (EAA/NEAA) was 60.46%.The proportion of flavor amino acid in total amino acid was more than 40%.Sulphur amino acids (methionine and cystine) were its first limiting essential amino acid.In addition,both of its water and alcohol extract (500 μg/mL) showed inhibitory activity on α-glucosidase,with inhibition rates of 43.75% and 39.90% respectively.

Key words: Alisma orientale, nutrients, &alpha, -glucosidase inhibition, amino acids assessment