ABSTRACT
This study was aimed to analyze the major protein composition of centipedes (Scolopendra subspinipes mutilans L.Koch.), and the ACE inhibitory activity of its hydrolysis. Albumins, gulbulins, coixins and glutelins were sequentially extracted from centipedes flour with corresponding buffer and then quantified by Kjeldahl method and Brandford. Hydrolysation of four kinds of proteins of centipedes and the residues were conducted with pepsin. The hydrolysis was ultrafiltrated (MWCO=3 000) and lyophilized. The peptides (≤3 kD) were obtained to evalu-ate the ACE inhibitory activity by RP-HPLC. The results showed that the total protein content of centipedes was (62.69±1.41)%. Among which the contents of albumins, globulins, coixins, glutelins and residual were account-ing for (6.42±0.31)%, (7.94±0.24)%, (4.31±0.34)%, (40.66±0.56)% and (25.78±0.60)%, respectively. The inhibition rate of hydrolysis of four kinds of protein and residual were 50.28%, 57.37%, 31.15%, 58.99%, 80.81%, respectively. It was concluded that centipedes were rich in protein and the hydrolyzate of all proteins manifested ACE inhibitory activity at different extent. The residual and glutelins indicated strong ACE inhibitory potential by hydrolysis. This research provided valuable sights for exploring hypotensive activity and functional food from centi-pedes.
ABSTRACT
This study was aimed to optimize the hydrolysis conditions of Coix prolamin, which occupied the highest content in total protein of it, and then evaluate the angiotensin-converting enzyme (ACE) inhibitory activity of the corresponding hydrolysates. Pepsin was used to hydrolyze prolamin and OPA method was applied to determine the degree of hydrolysis. The optimum conditions of hydrolyzing prolamin were obtained by orthogonal design subse-quently. The ACE inhibitory activity of small molecular weight (less than 3 kD) peptides gained by ultrafiltration of the hydrolysates was assayed by RP-HPLC method. The result showed that the optimized hydrolysis conditions were substrate concentration of 1%, enzyme-to-substrate ratio of 1:5 and hydrolysis duration for 48 h. The hydrolysates exhibited an ACE inhibitory ratio of (83.40 ± 0.93)% at the concentration of 0.1 mg·mL-1. It was concluded that prolamin hydrolysates displayed a high ACE inhibitory activity in vitro, which provided guidance for further research of antihypertensive component and development of functional food from Coix.
ABSTRACT
Flavonoids, which is composed of a C6-C3-C6 backbone, is a kind of secondary metabolites of Chinese materia medica (CMM). It has received extensive attention from all over the world and obtained a rapid develop-ment due to its widespread distribution, structural complexity and active diversity. This article has summarized the progress of flavonoids both in antioxidant activity and in mechanism, so as to provide some references for the re-search and development of new medicine of flavonoids with antioxidant activity.