Small Molecular Fraction Research Articles

Novel glucomannan-like polysaccharide from Lycium barbarum L. ameliorates renal fibrosis via blocking macrophage-to-myofibroblasts transition

The macrophage to myofibroblasts transition (MMT) has been reported as a newly key target in renal fibrosis. Lycium barbarum L. is a traditional Chinese medicine for improving renal function, in which its polysaccharides (LBPs) are the mainly active components. However, whether the role of LBPs in treating renal fibrosis is related to MMT process remain unclear. The purpose of this study was to explore the relationship between the regulating effect on MMT process and the anti-fibrotic effect of LBPs. Initially, small molecular weight LBPs fractions (LBP-S) were firstly isolated via Sephadex G-100 column. Then, the potent inhibitory effect of LBP-S on MMT process was revealed on bone marrow-derived macrophages (BMDM) model induced by TGF-β. Subsequently, the chemical structure of LBP-S was elucidated through monosaccharide, methylation and NMR spectrum analysis. In vivo biodistribution characteristics studies demonstrated that LBP-S exhibited effectively accumulation in kidney via intraperitoneal administration. Finally, LBP-S showed a satisfactory anti-renal fibrotic effect on unilateral ureteral obstruction operation (UUO) mice, which was significantly reduced following macrophage depletion. Overall, our findings indicated that LPB-S could alleviate renal fibrosis through regulating MMT process and providing new candidate agents for chronic kidney disease (CKD) related fibrosis treatment.

Angiotensin-Converting Enzyme and Renin-Inhibitory Activities of Protein Hydrolysates Produced by Alcalase Hydrolysis of Peanut Protein.

Hypertension is a major controllable risk factor associated with cardiovascular disease (CVD) and overall mortality worldwide. Most people with hypertension must take medications that are effective in blood pressure management but cause many side effects. Thus, it is important to explore safer antihypertensive alternatives to regulate blood pressure. In this study, peanut protein concentrate (PPC) was hydrolyzed with 3-5% Alcalase for 3-10 h. The in vitro angiotensin-converting enzyme (ACE) and renin-inhibitory activities of the resulting peanut protein hydrolysate (PPH) samples and their fractions of different molecular weight ranges were determined as two measures of their antihypertensive potentials. The results show that the crude PPH produced at 4% Alcalase for 6 h of hydrolysis had the highest ACE-inhibitory activity with IC50 being 5.45 mg/mL. The PPH samples produced with 3-5% Alcalase hydrolysis for 6-8 h also displayed substantial renin-inhibitory activities, which is a great advantage over the animal protein-derived bioactive peptides or hydrolysate. Remarkably higher ACE- and renin-inhibitory activities were observed in fractions smaller than 5 kDa with IC50 being 0.85 and 1.78 mg/mL. Hence, the PPH and its small molecular fraction produced under proper Alcalase hydrolysis conditions have great potential to serve as a cost-effective anti-hypertensive ingredient for blood pressure management.

Extraction, structural characterization, and antioxidant activity of polysaccharides from three microalgae

Microalgal polysaccharides have received much attention due to their potential value in preventing and regulating oxidative damage. This study aims to reveal the mechanisms of regulating oxidative stress and the differences in the yield, structure, and effect of polysaccharides extracted from three microalgae: Golenkinia sp. polysaccharides (GPS), Chlorella sorokiniana polysaccharides (CPS), and Spirulina subsalsa polysaccharides (SPS). Using the same extraction method, GPS, CPS, and SPS were all heteropoly- saccharides composed of small molecular fraction: the monosaccharides mainly comprised galactose (Gal). Among the three, SPS had a higher proportion of small molecular fraction, and a higher proportion of Gal; thus it had the highest yield and antioxidant activity. GPS, CPS, and SPS all showed strong antioxidant activity in vitro, and showed strong ability to regulate oxidative stress, among which SPS was slightly higher. From the analysis of gene expression, the Nrf2-ARE signalling pathway was an important pathway for GPS, CPS, and SPS to regulate cellular oxidative stress. This study provides a theoretical foundation for further research on the utilization of microalgae polysaccharides and product development.

First Results from the JWST Early Release Science Program Q3D: The Warm Ionized Gas Outflow in z ∼ 1.6 Quasar XID 2028 and Its Impact on the Host Galaxy

Quasar feedback may regulate the growth of supermassive black holes, quench coeval star formation, and impact galaxy morphology and the circumgalactic medium. However, direct evidence for quasar feedback in action at the epoch of peak black hole accretion at z ≈ 2 remains elusive. A good case in point is the z = 1.6 quasar WISEA J100211.29+013706.7 (XID 2028), where past analyses of the same ground-based data have come to different conclusions. Here, we revisit this object with the integral-field unit of the Near Infrared Spectrograph on board the JWST as part of Early Release Science program Q3D. The excellent angular resolution and sensitivity of the JWST data reveal new morphological and kinematic substructures in the outflowing gas plume. An analysis of the emission-line ratios indicates that photoionization by the central quasar dominates the ionization state of the gas with no obvious sign for a major contribution from hot young stars anywhere in the host galaxy. The rest-frame near-UV emission aligned along the wide-angle cone of outflowing gas is interpreted as a scattering cone. The outflow has cleared a channel in the dusty host galaxy, through which some of the quasar ionizing radiation is able to escape and heat the surrounding interstellar and circumgalactic media. Although the warm ionized outflow is not powerful enough to impact the host galaxy via mechanical feedback, radiative feedback by the active galactic nucleus, aided by the outflow, may help to explain the unusually small molecular gas mass fraction in the galaxy host.

Enhanced self-sintering mechanical strength of carbon blocks via removal of light molecular-weight compound in green petroleum coke

Self-sintering of green petroleum coke (GPC) offers a critical approach to prepare high performance carbon blocks owing to its remarkable homogeneity and high stability. However, the volatilization of small molecular fractions in green coke inevitably results in the formation of pores and cracks, thus severely limiting its commercial application. Herein, the GPC is divided into two soluble fractions with different molecular weight distribution, including dichloromethane-soluble (DCMS, 560.76 m/z) and dichloromethane-insoluble-toluene-soluble (DCMI-TS, 624.39 m/z), by sequential extraction with dichloromethane (CH2Cl2) and toluene based on processes of ultrasonic accompanying with continuous mechanical stirring for 4 h aging for 24 h and stirring at 130 ℃ for 4 h, respectively. All compounds extracted from GPC were further investigated via various characterizations, such as chromatography, ESR, elemental analysis, thermogravimetry, mass spectrometry, NMR, UV–Visible and FTIR, to verify their molecular weight distributions, chemical compositions, and reactivities. While DCMS contains long alkyl side chains, there are more naphthenic and oxygen-containing compounds and plasticizer species e.g. dibutyl phthalate in DCMI-TS. Thanks to the removal of volatile small molecular, when the solvent purified GPC were employed as precursor, the obtained carbon block (DCMI-C) demonstrates an apparent density of 1.48 g·cm−3, which is obviously higher than that of pristine GPC-C (1.34 g·cm−3). 1.7 times larger flexural strength, as well as 1.9 times higher compressive strength is found for DCMI-C compared to GPC-C, indicating that the DCM soluble compounds are the mainly reason for microcracks and pores generation. In addition, a much more compacted pore structure, as reflected in SEM images, is also observed in DCMI-C implying its remarkable mechanical intensity. Impressively, plasticizer species can also promote the self-sintering behavior of the green body where an enhanced mechanical property was achieved when 2 % dibutyl phthalate was added into DCMI mixtures.

New insights into interfacial interaction and nanoconfinement effect in synergistic oxidation-filtration via CoFe2O4-ceramic membrane activated peroxymonosulfate

Ceramic membranes incorporating CoFe2O4 (CoFeCM) were synthesized to activate peroxymonosulfate (PMS), and the performance and mechanisms of its oxidation-filtration were comprehensively investigated. The catalytic filtration performance of CoFeCM/PMS was evaluated by degradation of organic pollutants and the mitigation of membrane fouling. Results indicated that CoFeCM/PMS effectively removed toxic micropollutants, including phenol (82.56%), atrazine (93.42%), and carbamazepine (87.40%), ensuring the permeate quality and safety. Also, this synergistic process notably improved the degradation of natural organic matter (NOM) in the secondary effluent and Songhua River water. CoFeCM/PMS filtration effectively mitigated membrane fouling caused by three typical model organics, reducing their irreversible membrane fouling resistance by 70.85–83.62%, and increasing the normalized flux to 48.74–82.61%. The membrane fouling derived from two actual water systems was also greatly alleviated by CoFeCM/PMS. Based on the Extended Derjaguin-Landau-Verwey-Overbeek theory analysis, NOM was oxidized by reactive oxide species into hydrophilic small molecular fractions, resulting in remarkably increased repulsive interaction between NOM and CoFeCM surface. Density functional theory calculation results confirmed the nanoconfinement effect in CoFeCM pores, which can slow down the growth of foulants in pores and effectively alleviate irreversible membrane fouling. Consequently, standard blocking transformed into the dominant membrane fouling pattern due to the synergistic effects of nanoconfinement catalysis (in membrane pores) and repulsive interactions (on membrane surface) during oxidation-filtration.

Microcapsules with slow-release characteristics prepared by soluble small molecular starch fractions through the spray drying method

The utilization of starch in the food and medical industry can be facilitated by using new non-chemical methods to make starch the only wall material to encapsulate microcapsules. In this study, soluble small molecular fraction obtained from corn starch by gelatinization and centrifugation methods and commercial soluble starch were used independently to encapsulate oil under the condition that wall material and core material were 2:1. Molecular weight of these starch fractions was measured firstly. The peak molecular weight of the soluble small molecular fraction of corn starch and commercial soluble starch was 3.537 × 105 Da and 2.720 × 104 Da, respectively. Basic physicochemical characteristics and application characteristics of the microcapsules were then characterized and compared. The soluble small molecular fraction of corn starch encapsulated microcapsule and the commercial soluble starch encapsulated microcapsule had high encapsulation efficiency (higher than 88%), high boiling water solubility (higher than 74%), high rehydration stability (higher than 2 h). Most importantly, the encapsulated oil of these microcapsules could be slowly released under the action of α-amylase and amyloglucosidase. Overall, both the soluble small molecular fraction of corn starch and commercial soluble starch could be used as microcapsule wall materials and might have great application potential in food and medicine.

Simultaneous removal of nitrogen and dimethyl phthalate from low-carbon wastewaters by using intermittently-aerated constructed wetlands

Phthalic acid esters (PAEs) such as dimethyl phthalate (DMP) have been widely used as a plasticizer in society, which pose severe harm to human health. In this study, the potential of DMP elimination and nitrogen removal from low-carbon wastewaters by intermittently-aerated subsurface flow constructed wetlands (SSFCWs) was evaluated, and the effect of the influent DMP concentrations on nitrogen removal was also investigated. The results showed a better removal of DMP (88.5–97.8%) was obtained in CWs under different influent DMP concentrations, and the high removal of COD (86.7–95.0%) and NH4+-N (95.5–98.7%) was also achieved simultaneously. The maximum TN removal (48.7%) was observed at an influent DMP concentration of 10 mg L−1. Furthermore, the TN removal and DMP reduction had a good fitting relationship (R2 = 0.71) in CWs under different influent DMP concentrations. The analysis of DMP decomposition processes demonstrated that DMP was degraded into some smaller molecular fractions, and DMP degradation intermediates mainly including monomethyl phthalate (MMP) and phthalate (PA), which might provide a potential carbon source for the denitrification processes in CWs. These findings could contribute to a better understanding of DMP removal mechanism and provide useful guidance for the practical application of CWs for treating wastewater containing phthalates.

Spectrum-effect relationship between fingerprints and hemopoietic effects of small molecular fraction of Polygoni Multiflori radix praeparata.

Polygoni multiflori Radix Praeparata (PMRP) is a traditional medicine used for nourishing essence and blood in China. However, it is unclear which PMRP compounds are responsible for its hematopoietic effect. In this study, spectrum-effect relationship was used to discovery potential hematopoietic compounds. The fingerprints of 20 PMRP batches were established by HPLC and the hematopoietic effect was determined using red blood cell, hemoglobin, hematocrit, and platelet indexes in aplastic anemia model mice. The spectrum-effect relationship between common peaks and hematopoietic efficacy values was established using gray relational analysis and partial least squares analysis. Spectrum-effect relationship results showed that peaks 21 (emodin-8-O-(6´-O-acetyl)-β-D-glucoside), 15 (2, 3, 5, 4'-tetrahydroxystilbene-2-O-di-glucoside), 16 (cis-2,3,5,4'-tetrahydroxy-stilbene-2-O-β-D-glucoside), 11 (unknown), 20(unknown, 12 (epicatechin), 29 (carboxyl emodin), and 31 (emodin) in the fingerprints were closely related to the hematopoietic effect. This work successfully established the spectrum-effect relationship between PMRP hematopoietic effect and its fingerprints, which can be used to explain the material basis for the PMRP hematopoietic effect.

The severity of immunocomplex responses in patients with recurrent depressive disorder

The immunocomplex responses in patients with recurrent depressive disorder (RDD) was studied. It has been established that the concentration of circulating immune complexes incl. most pathogenic average and small molecular fractions and phagocytic activity of monocytes in patients with RDD was changed. Changes in immunocomplex responses were most pronounced when more severely manifested in “Major depressive disorder, recurrent episode, severe without psychotic symptoms”(F33.2). Key words: recurrent depressive disorder, immunocomplex responses, conventional treatment

Effect of ɣ-irradiation on the microbial inactivation, nutritional value, and antioxidant activities of infant formula

This study was aimed to assess the effect of ɣ-irradiation (0 kGy, 5 kGy, and 10 kGy) on the microbial inactivation of selected pathogens (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157: H7, and Salmonella typhimurium), nutrient composition (lactose, protein, vitamin C, and fat quality), peptide profile, and antioxidant activities of a liquid formulation and powdered infant formula. Depending on the pathogens, the D10 values (kGy) were range from 0.28˗2.37 and 0.57˗6.13 for liquid formulation and powdered samples, respectively. Results also showed that except for L. monocytogenes and S. typhimurium, all inoculated pathogens were more sensitive toward irradiation in the liquid formulation. Furthermore, irradiation treatment did not bring any significant alteration in lactose and protein content of both types of samples while antioxidant properties and vitamin C levels were affected when irradiated in liquid formulation. However, irradiated powdered samples showed a significant dose-dependent increment in lipid oxidation up to 10 kGy, which led to detect the greater level of malondialdehyde by thiobarbituric acid-reactive substances assay. A dose of 5 kGy favours the release of small molecular protein fraction which can have a positive effect on the nutritional value of the irradiated infant formula.

Preventive Effect of Small Molecular Fraction of Irpex lacteus (Agaricomycetes) Fruiting Body against Chronic Nephritis in Mice and Identification of Active Compounds.

Previous study found that the fruit body of Irpex lacteus has an effect on the prevention and treatment of chronic nephritis. In this study, we systematically investigated the preventive effect of small molecular fraction (SMF) of the fungal fruit body against chronic nephritis. In addition, we analyzed, isolated, and identified the chemical constituents of SMF, and screened the activity of three small peptides isolated in vitro. The results showed SMF significantly reduced amounts of urine protein (UP), the content of urea (BUN), creatinine (Cr), tumor necrosis factor-α (TNF-α), and maleic dialdehyde (MDA) in serum, and significantly increased superoxide dismutase (SOD) level in renal tissue homogenate (P < 0.05). Moreover, the results of hematoxylin and eosin (H&E) and Masson staining of renal tissues indicated that SMF has protective effects on renal tissues and prevents renal interstitial from fibrosis. The peptide sequences isolated from SMF were identified as WSMGPAPDSVH (SP1), QCTGNASCSPPC (SP2), and HYCCTAKYA (SP3), which were active compounds for the prevention of nephritis, and these new peptides were isolated for the first time. The cell proliferation assay showed that 10 μg/L transforming growth factor-β1 (TGF-β1) significantly induced the proliferation of human renal tubular epithelial cells (HK-2), compared with the control group, and the difference was statistically significant (P < 0.01). However, when combined with three small peptides, respectively, the cell proliferation was significantly inhibited (P < 0.05). These results suggest that isolated peptides can maintain the morphological stability of HK-2 cells, inhibit cell proliferation induced by TGF-β1 to some extent, and prevent cell fibrosis.

Hematopoietic effect of small molecular fraction of Polygoni multiflori Radix Praeparata in cyclophosphamide-induced anemia mice.

The aim of this study is to investigate the protective effects of a small molecular fraction (SMF) of Polygoni multiflori Radix Praeparata (PMRP) in a cyclophosphamide (CTX) induced anemia mouse model. Small molecular fraction of PMRP was prepared and identified by high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS). In pharmacology, we examined the peripheral hemogram and thymus and spleen index. The content of granulocyte-macrophage colony-stimulating factor (GM-CSF) in serum was mensurated by enzyme-linked immunosorbent assay (ELISA); The level of superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (T-AOC), and malondialdehyde (MDA) in serum and spleen tissue homogenate were detected, and glutathione peroxidase (GSH-PX) was assayed in spleen. The results show that SMF can significantly accelerate the recovery of peripheral hemogram, increase the activity of antioxidant enzymes and GM-CSF in serum and spleen. SMF also increases the number of spleen cells, improves bone marrow pathology. In conclusion, the SMF of PMRP promoted the recovery of hematopoietic function in a CTX-induced anemia mouse, which can support SMF to be used as an adjunct to chemotherapy to counteract its side effects.

Dry heating and annealing treatment synergistically modulate starch structure and digestibility

To modulate starch digestibility, dry heating combined with annealing treatment was employed to synergistically modulate structure and digestibility of normal maize starch (NMS) and potato starch (PS). Dry heating decreased starch molecular weight and created small molecular fractions with suitable chain length, resulting in starch better rearrangement during annealing treatment. Accordingly, after dry heating combined with annealing treatment starches had the highest pasting temperature, the thinnest and the thickest of crystalline lamellae for NMS and PS, respectively, and the highest ordered structures of cooked-starch compared with single dry heating or annealing modified starches. The results revealed that the synergistic modification altered starch lamellar thickness and increased double helices orders. Thereby, dry heating combined with annealing treated starches exhibited the lowest enzymatic digestibility with increased ca. 7.90% of slowly digestible starch for NMS or elevated ca. 5.04% of resistant starch for PS. The differential changes caused by dry heating combined with annealing treatment between NMS and PS were comprehensively discussed and the difference should result from the different starch crystalline structure and average chain length. This study provides a promising pathway for modulating starch structures and enzymatic digestibility.

Dimethyl phthalate elimination from micro-polluted source water by surface discharge plasma: Performance, active species roles and mechanisms

Plasticizer pollution brought huge risks to ecological environment and human health. Surface discharge plasma (SDP) was employed to eliminate plasticizer in natural water, with dimethyl phthalate (DMP) as a typical plasticizer. Experimental results showed that DMP degradation efficiency reached 82.8% within 60 min’s SDP treatment, and the elimination process fitted well the first-order kinetic model. Low initial DMP concentration, alkaline condition, and low natural organic matter content were all conducive for DMP degradation. The contributions of OH radical and O2− to DMP elimination were 91.9% and 78.1%, respectively. Total organic carbon (TOC), UV–vis spectroscopy, and atomic force microscopy analysis demonstrated that DMP molecular structure was destroyed after the SDP treatment, and some small molecular fractions were generated. Approximately 47.8% of TOC and 73.5% of COD were eliminated after 60 min’s SDP treatment. Phthalic acid monomethyl ester, phthalic acid, o-phthalic anhydride, acetic acid, formic acid, and oxalic acid were detected as the byproducts. Carbon balance analysis among these intermediates showed that total carbon content was approximately 4.64 × 10-2 mmol before treatment, and it was 4.578 × 10-2 mmol after treatment, suggesting that some C-containing intermediates still existed but not detected. DMP degradation pathways in the SDP system were proposed.

Evaluation of the potential of dimethyl phthalate degradation in aqueous using sodium percarbonate activated by discharge plasma

Phthalates, as additives in the plastic production process, were able to enter the water environment, causing huge risks to ecological environment and human health. The potential of phthalates elimination in aqueous using sodium percarbonate (SPC) activated by discharge plasma (marked as “SPC + plasma”) was evaluated, with dimethyl phthalate (DMP) as a model pollutant. Experimental results showed that about 92.1% of DMP was eliminated in the “SPC + plasma” system with the treatment time of 30 min, which was 30.7% higher than that in sole plasma system, and the synergetic intensity for DMP elimination reached up to 127.0; and the energy yield was also raised by 131%. H2O2 and OH radicals formation were promoted but ozone concentration decreased in the “SPC + plasma” system. Appropriate SPC dosage benefited DMP elimination, and the synergetic intensity increased from 2.0 to 127.0 as the SPC dosage increased from 0.06 mmol L−1 to 0.12 mmol L−1. OH radicals, O2·−, 1O2, and CO3·− played crucial roles in DMP elimination, and the roles of O2·− and 1O2 were strengthened in the “SPC + plasma” system. Ultraviolet–visible spectroscopy measurement, total content of organic carbon, atomic force microscopy and three-dimensional fluorescence analysis demonstrated that DMP molecular structure was destroyed during treatment, and some smaller molecular fractions were generated. The main intermediates included phthalic acid monomethyl ester, phthalic acid, o-phthalic anhydride, acetic acid, formic acid, and oxalic acid. The possible enhancement mechanisms for DMP elimination in the “SPC + plasma” system were proposed.

Simplified recovery of enzymes and nutrients in sweet potato wastewater and preparing health black tea and theaflavins with scrap tea

The industry discards generous organic wastewater in sweet potato starch factory and scrap tea in tea production. A simplified procedure to recover all biochemicals from the wastewater of sweet potato starch factory and use them to make health black tea and theaflavins from scrap green tea was developed. The sweet potato wastewater was sequentially treated by isoelectric precipitation, ultrafiltration and nanofiltration to recover polyphenol oxidase (PPO), β-amylase, and small molecular fractions, respectively. The PPO fraction can effectively transform green tea extracts into black tea with high content of theaflavins through the optimized fed-batch feeding fermentation. The PPO transformed black tea with sporamins can be used to make health black tea, or make theaflavins by fractionation with ethyl acetate. This work provides a resource- and environment-friendly approach for economically utilizing the sweet potato wastewater and the scrap tea, and making biochemical, nutrient and health products.

Microbial transglutaminase enhances antioxidant activity of yogurt through altering pattern of water‐soluble peptides and increasing release of amino acids

SummaryThis study compared the antioxidant capacity of yogurt with and without microbial transglutaminase treatment after milk fermentation, and investigated the correlation between antioxidant property and the water‐soluble peptides and amino acids composition. Results showed that small molecular peptide fraction exhibited stronger antioxidant activity than large peptides. Microbial transglutaminase yogurt isolated fraction had stronger antioxidant capacity than that from the control. Microbial transglutaminase altered the peptides composition, and resulted in higher amount of small molecular peptides (&lt;1.5 kDa) mainly consisting of κ‐casein‐derived peptides in yogurt. The dominant peptides sequences (IAKYI, IAKYIPI, IAKYIPIQY, PYYAK and NQFLPYPYYAK) in the treated yogurt were different from those in the control (PYPQ, VLPVPQKAVPYPQ, PVPQKAVPYPQ and VLSRYPSYGLN). Microbial transglutaminase improved the composition and concentration of amino acids in yogurt.

Chip-based magnetic solid phase microextraction coupled with ICP-MS for the determination of Cd and Se in HepG2 cells incubated with CdSe quantum dots

The quantification of trace Cd and Se in cells incubated with CdSe quantum dots (QDs) is critical to investigate the cytotoxicity of CdSe QDs. In this work, a miniaturized platform, namely chip-based magnetic solid phase microextraction (MSPME) packing with sulfhydryl group functionalized magnetic nanoparticles, was fabricated and combined with inductively coupled plasma mass spectrometry (ICP-MS) for the determination of trace Cd and Se in cells. Under the optimized conditions, the limits of detection (LOD) of the developed chip-based MSPME-ICP-MS system are 2.2 and 21ngL−1 for Cd and Se, respectively. The proposed method is applied successfully to the analysis of total and released small molecular fraction of Cd and Se in Human hepatocellular carcinoma cells (HepG2 cells) incubated with CdSe QDs, and the recoveries for the spiked samples are in the range of 86.0–109%. This method shows great promise to analyze cell samples and the obtained results are instructive to explore the cytotoxicity mechanism of CdSe QDs in cells.

Angiotensin I-converting enzyme inhibitory and hypocholesterolemic activities: Effects of protein hydrolysates prepared from Achatina fulica snail foot muscle

ABSTRACTThe angiotensin I-converting enzyme (ACE) inhibitory activity and hypocholesterolemic effect of Achatina fulica snail foot muscle protein hydrolysates (SFMPH) and its hydrolysates were studied. The SFMPHs were prepared at a temperature of 121°C for 60 min. To obtain the enzymatic hydrolysates, the SFMPHs were further hydrolysed with three proteases (papain, trypsin, or alcalase). Among all the hydrolysates, alcalase hydrolysate showed the highest degree of hydrolysis and was dominated by a small molecular size fraction (189–686 Da). The SFMPH treated by alcalase was effective in disintegrating intact cholesterol micelles. Furthermore, alcalase hydrolysate with a hydrolysis time of 60 min showed a strong ACE inhibitory activity in vitro with an IC50 of 0.024 mg/mL. Therefore, alcalase hydrolysate may be a promising ingredient for the use in functional foods.