US-20260125424-A1 - BIOACTIVE PEPTIDE PCT-1, AND PREPARATION METHOD AND APPLICATION THEREOF

Abstract

A bioactive peptide PCT-1, and preparation method and application thereof are provided. The amino acid sequence of the bioactive peptide PCT-1 is LNRTFE, as shown in SEQ ID NO: 1, and the bioactive peptide PCT-1 has antioxidant and intestinal flora-regulating functions. Extracted from spirulina protein peptides, the bioactive peptide PCT-1 can significantly increase the activities of SOD and GSH-Px in serum, and significantly reduce the content of MDA in serum; its in vivo antioxidant activity is comparable to that of the positive control Trolox. Meanwhile, compared with the blank control group, the bioactive peptide PCT-1 can also reduce the α-diversity index of intestinal flora, change the overall structure of intestinal flora, regulate the abundance of intestinal flora at various taxonomic levels, and significantly increase the contents of acetic acid and butyric acid. Therefore, the bioactive peptide PCT-1 can be applied in functional foods for antioxidation and intestinal flora regulation.

Inventors

• Wenjun Li
• TUANJIE CHE
• Song Qin
• Chenyang Lu
• Jinzhang XU
• Libo YAN
• Guizhen XIE
• Ying Kan

Assignees

• YANTAI INST COASTAL ZONE RES CAS
• YANTAI ZHIGONG BIOMEDICAL TECH CO LTD

Dates

Publication Date

20260507

Application Date

20251230

Priority Date

20241029

Claims (4)

1. 1 . A bioactive peptide PCT-1, wherein the amino acid sequence of the bioactive peptide PCT-1 is LNRTFE, as shown in SEQ ID NO: 1 in the sequence listing, and the bioactive peptide PCT-1 has antioxidant and intestinal flora-regulating functions.
2. 2 . An application of the bioactive peptide PCT-1 according to claim 1 in functional foods for antioxidation and intestinal flora regulation.
3. 3 . A preparation method of the bioactive peptide PCT-1 according to claim 1 , wherein the preparation method adopts a solid-phase synthesis method, specifically: using Fmoc-protected amino acids as raw materials and polystyrene resin as a solid-phase carrier, and performing solid-phase synthesis by adopting an Fmoc solid-phase synthesis strategy.
4. 4 . A preparation method of the bioactive peptide PCT-1 according to claim 1 , wherein the preparation method adopts an enzymatic hydrolysis method, specifically: (1) taking spirulina protein, adding water with a mass 9 times that of the spirulina protein, and adding a compound protease at an enzyme-to-substrate ratio of 0.5% for enzymatic hydrolysis; conducting the enzymatic hydrolysis at a temperature of 55° C. and a pH value of 8.0 for 6 h to obtain an enzymatic hydrolysate, wherein the compound protease is formed by mixing alkaline protease and neutral protease at a mass ratio of 1:1; (2) after the enzymatic hydrolysis is completed, filtering the enzymatic hydrolysate with eight layers of gauze to remove residues, so as to obtain a spirulina protein peptide enzymatic hydrolysate; and (3) freeze-drying the spirulina protein peptide enzymatic hydrolysate to obtain a spirulina protein peptide powder, wherein the spirulina protein peptide powder contains a relatively large amount of the bioactive peptide PCT-1.

Description

CROSS REFERENCE TO THE RELATED APPLICATIONS This application is a continuation application of International Application No. PCT/CN2024/130286, filed on Nov. 6, 2024, which is based upon and claims priority to Chinese Patent Application No. 202411514023.4, filed on Oct. 29, 2024, the entire contents of which are incorporated herein by reference. SEQUENCE LISTING The instant application contains a Sequence Listing which has been submitted in XML format via EFS-Web and is hereby incorporated by reference in its entirety. Said XML copy is named GBYTZX010-PKG_Sequence_Listing.xml, created on Nov. 25, 2025, and is 27,624 bytes in size. TECHNICAL FIELD The present invention relates to a small-molecule peptide, and preparation method and application thereof, and in particular to a small-molecule bioactive peptide PCT-1 with antioxidant and intestinal flora-regulating functions, as well as its preparation method and application in functional foods for antioxidation and intestinal flora regulation. The present invention belongs to the field of biotechnology. BACKGROUND The occurrence of various diseases such as obesity, aging, cancer, cardiovascular diseases, and Alzheimer's disease has been proven to be closely related to the excessive production of free radicals. The human body normally can regulate oxidative balance through a variety of antioxidant mechanisms, including scavenging free radicals to block the chain reaction of free radicals, chelating metal ions to inhibit the production of free radicals, and regulating endogenous glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) to scavenge free radicals. When the endogenous oxidative balance is disrupted, the body needs exogenous supplementation of antioxidants. Traditional antioxidants are generally derived from chemical synthesis and have shortcomings such as poor stability and strong toxic and side effects. In contrast, antioxidant peptides derived from protein hydrolysis have advantages such as safety, non-toxicity, and strong stability, which are more in line with consumer requirements. The human intestine contains approximately 1,000 species and 100 trillion microorganisms, mainly including bacteria, yeasts, and parasites. The number of genes carried by these intestinal microorganisms is more than 100 times that of human genes, and they are known as the “invisible organ”. Imbalance of intestinal flora is closely related to the occurrence of obesity, hypertension, intestinal inflammation, cardiovascular diseases, etc. Moreover, helping to regulate intestinal flora is also one of the functions that health food is allowed to claim in the Catalogue of Health Functions Allowed for Health Food Claims—Non-Nutrient Supplements (2023 Edition). In addition to the direct supplementation of probiotics, bioactive peptides have also been reported to have the function of regulating intestinal flora. In the graduation thesis Effects of Isolation and Purification Process on the Structure and Activity of Antioxidant Peptides from Tilapia Skin, Zuo Yijin described in detail the antioxidant activity of the enzymatic hydrolysate of tilapia skin, as well as the core functional antioxidant peptide components therein, such as the decapeptide PGIIGLPGPA (SEQ ID NO: 18), the octapeptide AVGPVGPS (SEQ ID NO: 19), and the octapeptide ERGPPGPP (SEQ ID NO: 20). In the graduation thesis Isolation, Identification and Functional Verification of Bioactive Peptides from Antarctic Krill, Wang Yiju described the process of preparing antioxidant peptides from Antarctic krill, proved that components with strong antioxidant activity are mainly enriched in low-molecular-weight polypeptides, and identified that the heptapeptide APGELPY (SEQ ID NO: 21), the hexapeptide DIFDPL (SEQ ID NO: 22), and the hexapeptide LDVAPL (SEQ ID NO: 23) have good antioxidant effects. In Isolation and Identification of Antioxidant Peptides Derived from Ovalipes punctatus Waste Containing Meat Scraps, Yu Hui described the evaluation of the antioxidant activity of the trypsin enzymatic hydrolysate of the Ovalipes punctatus waste containing meat scraps, and isolated two antioxidant peptides with strong ABTS+ scavenging ability, namely the tripeptide YEG and the dipeptide YE. In addition, Feng Ziqi et al. described the regulatory effect of bioactive peptides from Mytilus coruscus on the intestinal flora of mice with alcohol-induced liver injury in the article Protective Effects of Bioactive Peptides from Mytilus coruscus on Alcohol induced Liver Injury and Their Regulation of Gut Microbiota in Mice; in the graduation thesis Study on the Effect of Giant Salamander Bioactive Peptides on Intestinal Flora, Chen Xinai specifically studied the regulatory effect of giant salamander bioactive peptides on the intestinal flora structure and metabolism of obese mice induced by a high-fat diet. In the graduation thesis Preparation and Activity Study of Collagen Peptides from Micropterus salmoides Skin, Han