Potent Angiotensin Converting Enzyme Research Articles

Computational assessment of targeting angiotensin-converting enzyme for hypertension management: A structure-based virtual screening approach

Background: Hypertension is a growing public health concern globally. The angiotensin-converting enzyme (ACE) is an enzyme that cleaves the carboxy-terminal His-Leu dipeptide from angiotensin I, yielding the potent vasopressor octapeptide, angiotensin II. ACE inhibitors are a primary treatment option for hypertension, heart failure, and myocardial infarction. However, the use of synthetic ACE inhibitors has been linked to a number of side effects. Therefore, the development of novel and safe ACE inhibitors is a need of time.Methods: This study used a computational screening of a library of known compounds with anti-inflammatory activities against the active site of ACE using the PyRx-Python 0.8 tool to find more potent ACE inhibitors with less or no side effects. The physicochemical properties of the anti-inflammatory compounds were obtained from the Life Chemicals website.Result: The five hits, specifically F3398-2114, F0193-0245, F0163-0089, F0193-0237, and F0302-0060, exhibited notable interactions within the ACE binding pocket and demonstrated greater binding energy compared to the control compound, Lisinopril. All of these compounds displayed favorable physicochemical characteristics and aligned to Lipinski's rule.Conclusion: The compounds F3398-2114, F0193-0245, F0163-0089, F0193-0237, and F0302-0060 have the potential to be used as ACE inhibitors; however, further experimental validation is required to optimize them as ACE inhibitors.Keywords: Hypertension; Angiotensin-converting enzyme; Heart failure; Lipinski's rule

Conditional Cell-Penetrating Peptide Exposure as Selective Nanoparticle Uptake Signal.

A major bottleneck diminishing the therapeutic efficacy of various drugs is that only small proportions of the administered dose reach the site of action. One promising approach to increase the drug amount in the target tissue is the delivery via nanoparticles (NPs) modified with ligands of cell surface receptors for the selective identification of target cells. However, since receptor binding can unintentionally trigger intracellular signaling cascades, our objective was to develop a receptor-independent way of NP uptake. Cell-penetrating peptides (CPPs) are an attractive tool since they allow efficient cell membrane crossing. So far, their applicability is severely limited as their uptake-promoting ability is nonspecific. Therefore, we aimed to achieve a conditional CPP-mediated NP internalization exclusively into target cells. We synthesized different CPP candidates and investigated their influence on nanoparticle stability, ζ-potential, and uptake characteristics in a core-shell nanoparticle system consisting of poly(lactid-co-glycolid) (PLGA) and poly(lactic acid)-poly(ethylene glycol) (PLA10kPEG2k) block copolymers with CPPs attached to the PEG part. We identified TAT47-57 (TAT) as the most promising candidate and subsequently combined the TAT-modified PLA10kPEG2k polymer with longer PLA10kPEG5k polymer chains, modified with the potent angiotensin-converting enzyme 2 (ACE2) inhibitor MLN-4760. While MLN-4760 enables selective target cell identification, the additional PEG length hides the CPP during a first unspecific cell contact. Only after the previous selective binding of MLN-4760 to ACE2, the established spatial proximity exposes the CPP, triggering cell uptake. We found an 18-fold uptake improvement in ACE2-positive cells compared to unmodified particles. In summary, our work paves the way for a conditional and thus highly selective receptor-independent nanoparticle uptake, which is beneficial in terms of avoiding side effects.

In Silico Screening of Bioactive Peptides in Stout Beer and Analysis of ACE Inhibitory Activity.

Stout beer was selected as the research object to screen angiotensin-converting enzyme (ACE) inhibitory peptides. The peptide sequences of stout beer were identified using ultra-performance liquid chromatography-quadrupole-Orbitrap mass spectrometry with de novo, and 41 peptides were identified with high confidence. Peptide Ranker was used to score the biological activity and six peptides with a score ≥ 0.5 were screened to predict their potential ACE inhibitory (ACEI) activity. The toxicity, hydrophilicity, absorption, and excretion of these peptides were predicted. In addition, molecular docking between the peptides and ACE revealed a significant property of the peptide DLGGFFGFQR. Furthermore, molecular docking conformation and molecular dynamics simulation revealed that DLGGFFGFQR could be tightly bound to ACE through hydrogen bonding and hydrophobic interaction. Lastly, the ACEI activity of DLGGFFGFQR was confirmed using in vitro evaluation and the IC50 value was determined to be 24.45 μM.

Optimization of Extraction Process and Activity of Angiotensin-Converting Enzyme (ACE) Inhibitory Peptide from Walnut Meal.

In order to further realize the resource reuse of walnut meal after oil extraction, walnut meal was used as raw material to prepare polypeptide, and its angiotensin-converting enzyme (ACE) inhibitory activity was investigated. The ACE inhibitory peptides were prepared from walnut meal protein by alkaline solution and acid precipitation. The hydrolysis degree and ACE inhibition rate were used as indexes to optimize the preparation process by single-factor experiment and response surface method. The components with the highest ACE activity were screened by ultrafiltration, and their antioxidant activities were evaluated in vitro. The effect of gastrointestinal digestion on the stability of walnut peptide was analyzed by measuring molecular weight and ACE inhibition rate. The results showed that the optimal extraction conditions were pH 9.10, hydrolysis temperature 54.50 °C, and hydrolysis time 136 min. The ACE inhibition rate of walnut meal hydrolysate (WMH) prepared under these conditions was 63.93% ± 0.43%. Under the above conditions, the fraction less than 3 kDa showed the highest ACE inhibitory activity among the ACE inhibitory peptides separated by ultrafiltration. The IC50 value of scavenging ·OH free radical was 1.156 mg/mL, the IC50 value of scavenging DPPH free radical was 0.25 mg/mL, and the IC50 value of scavenging O2- was 3.026 mg/mL, showing a strong total reducing ability. After simulated gastrointestinal digestion in vitro, the ACE inhibitory rate of walnut peptide decreased significantly, but it still maintained over 90% ACE inhibitory activity. This study provides a reference for the application of low-molecular-weight walnut peptide as a potential antioxidant and ACE inhibitor.

Antioxidant and Angiotensin-Converting Enzyme Inhibitory Activity of Faba Bean-Derived Peptides After In Vitro Gastrointestinal Digestion: Insight into Their Mechanism of Action.

Faba bean flour, after in vitro gastrointestinal digestion, showed important antioxidant and angiotensin-converting enzyme (ACE) inhibitory activities. In the present study, 11 faba bean- derived peptides were synthesized to confirm their bioactivities and provide a deeper understanding of their mechanisms of action. The results revealed that 7 peptides were potent antioxidants, namely, NYDEGSEPR, TETWNPNHPEL, TETWNPNHPE, VIPTEPPH, VIPTEPPHA, VVIPTEPPHA, and VVIPTEPPH. Among them, TETWNPNHPEL had the highest activity in the ABTS (EC50 = 0.5 ± 0.2 mM) and DPPH (EC50 = 2.1 ± 0.1 mM) assays (p < 0.05), whereas TETWNPNHPE had the highest activity (p < 0.05) in the ORAC assay (2.84 ± 0.08 mM Trolox equivalent/mM). Synergistic and/or additive effects were found when selected peptides (TETWNPNHPEL, NYDEGSEPR, and VVIPTEPPHA) were combined. Four peptides were potent ACE inhibitors, where VVIPTEPPH (IC50 = 43 ± 1 μM) and VVIPTEPPHA (IC50 = 50 ± 5 μM) had the highest activity (p < 0.05), followed by VIPTEPPH (IC50 = 90 ± 10 μM) and then VIPTEPPHA (IC50 = 123 ± 5 μM) (p < 0.05). These peptides were noncompetitive inhibitors, as supported by kinetic studies and a molecular docking investigation. This study demonstrated that peptides derived from faba beans have multifunctional bioactivities, making them a promising food-functional and nutraceutical ingredient.

Impact of Lactiplantibacillus plantarum and casein fortification on angiotensin converting enzyme inhibitory peptides in yogurt: identification and in silico analysis.

In this study, the effects of Lactiplantibacillus plantarum M11 (Lb. plantarum M11) in conjunction with sodium caseinate on the characteristics and angiotensin converting enzyme (ACE) inhibitory activity of yogurt were investigated. ACE inhibitory peptides (ACEIPs) in yogurt were identified by nano-LC-MS/MS and potential ACEIPs were predicted by in silico and molecular docking methods. The results showed that the ACE-inhibitory activity of yogurt was significantly enhanced (p < 0.05), while maintaining the quality characteristics of the yogurt. Thirteen ACEIPs in the improved yogurt (883 + M11-CS group) were identified, which were more abundant than the other yogurt groups (control 883 group, 883 + M11 group and 883-CS group). Two novel peptides with potential ACE inhibitory activity, YPFPGPIH and NILRFF, were screened. The two peptides showed PeptideRanker scores above 0.8, small molecular weight and strong hydrophobicity, and were non-toxic after prediction. Molecular docking results showed that binding energies with ACE were -9.4 kcal mol-1 and -10.7 kcal mol-1, respectively, and could bind to the active site of ACE. These results indicated that yogurt with Lb. plantarum M11 and sodium caseinate has the potential to be utilized as a functional food with antihypertensive properties. The combination of ACEIP-producing strains and casein fortification could be an effective method to promote the release of ACEIPs from yogurt.

Discovery of Potent Angiotensin-Converting Enzyme Inhibitors in Pomegranate as a Treatment for Hypertension.

Pomegranate (Punica granatum L.) is associated with numerous health benefits due to its high levels of antioxidant polyphenolic substances. Since pomegranate extract has been shown to inhibit angiotensin-converting enzyme (ACE), the potential inhibitory effect of most of its main constituents against ACE is unknown. Therefore, we tested the activities of 24 major compounds, the majority of which significantly inhibited ACE. Notably, pedunculagin, punicalin, and gallagic acid were the most effective ACE inhibitors with IC50 values of 0.91, 1.12, and 1.77 μM, respectively. As demonstrated in molecular docking studies, compounds block ACE by forming multiple hydrogen bonds and hydrophobic interactions with catalytic residues and zinc ions in ACE's C- and N-domains, consequently inhibiting ACE's catalytic activity. Also, the most active pedunculagin stimulated nitric oxide (NO) production, activated the endothelial nitric oxide synthase enzyme (eNOS), and significantly increased eNOS protein expression levels up to 5.3-fold in EA.hy926 cells. Furthermore, pedunculagin increased in cellular calcium (Ca2+) concentration promoted eNOS enzyme activation and reduced the production of reactive oxygen species (ROS). In addition, the active compounds improved glucose uptake in insulin-resistant C2C12 skeletal muscle cells in a dose-dependent manner. The results of these computational, in vitro, and cellular experiments provide further evidence to the traditional medicine that involves using pomegranates to treat cardiovascular diseases like hypertension.

Release of an encrypted, highly potent ACE-inhibitory peptide by enzymatic hydrolysis of moth bean (Vigna aconitifolia) protein.

Dietary approaches for the regulation of blood pressure are the need of the hour. Hence, identifying the foods possessing such activity is gaining importance. With this aim, moth bean (Vigna aconitifolia), an underutilized pulse, was explored for the presence of antihypertensive activity in terms of angiotensin converting enzyme (ACE)-inhibition bioactivity. Defatted moth bean protein concentrate was hydrolyzed by using different proteases including Alcalase, papain, and trypsin, to identify the enzyme producing highly potent ACE inhibitory peptides. The hydrolysate showing the highest ACE inhibitory activity was further fractionated using an ultrafiltration membrane (10, 3 and 1 kDa) based on ACE inhibitory activity. The active fraction was further subjected to the ion-exchange chromatography followed by RP-HPLC and LC-MS/MS analysis for the enrichment and identification of ACE inhibitory peptides. Finally, based on the bioinformatic analysis, few peptides were synthesized and evaluated for ACE inhibitory activity, followed by docking study and molecular dynamic simulation of a peptide with the highest ACE inhibitory activity. Out of the three proteases, Alcalase-derived hydrolysate showed the highest (~59%) ACE inhibition activity. Molecular weight-based fractionation revealed that <1 kDa fraction possessed the highest ACE inhibitory activity. Activity guided separation of 1 kDa fraction using ion-exchange chromatography, RP-HPLC and LC-MS/MS showed the presence of about 45 peptides. Based on the bioinformatic analysis, 15 peptides were synthesized and evaluated for ACE inhibitory activity. Among these, a novel octapeptide FPPPKVIQ showed the highest ACE inhibitory activity (93.4%) with an IC50 of 0.24 μM. This peptide retained about 59% activity post gastrointestinal digestion simulation. A Dixon plot as well as docking studies revealed the uncompetitive inhibitory nature of this peptide with a Ki value of 0.81 μM. Molecular dynamic simulation studies till 100 ns ensured the stability of the ACE-peptide complex. Thus, present study identified a novel potent ACE inhibitory peptide from moth bean that can be incorporated in a functional dietary formulation for regulation of hypertension.

Identification and Characterization of Novel ACE Inhibitory and Antioxidant Peptides from Sardina pilchardus Hydrolysate.

Sardina pilchardus is a valuable source of bioactive peptides with potential applications in functional foods. In this study, we investigated the angiotensin-converting enzyme (ACE) inhibitory activity of Sardina pilchardus protein hydrolysate (SPH) produced using dispase and alkaline protease. Our results showed that the low molecular mass fractions (<3 kDa) obtained through ultrafiltration exhibited more effective ACE inhibition, as indicated by screening with ACE inhibitory activity. We further identified the low molecular mass fractions (<3 kDa) using an LC-MS/MS rapid screening strategy. A total of 37 peptides with potential ACE inhibitory activity were identified based on high biological activity scores, non-toxicity, good solubility, and novelty. Molecular docking was used to screen for peptides with ACE inhibitory activity, resulting in the identification of 11 peptides with higher -CDOCKER ENERGY and -CDOCKER INTERACTION ENERGY scores than lisinopril. The sequences FIGR, FILR, FQRL, FRAL, KFL, and KLF were obtained by synthesizing and validating these 11 peptides in vitro, all of which had ACE inhibitory activity, as well as zinc-chelating capacity. All six peptides were found to bind to the three active pockets (S1, S2, and S1') of ACE during molecular docking, indicating that their inhibition patterns were competitive. Further analysis of the structural characteristics of these peptides indicated that all six peptides contain phenylalanine, which suggests that they may possess antioxidant activities. After experimental verification, it was found that all six of these peptides have antioxidant activities, and we also found that the SPH and ultrafiltration fractions of SPH had antioxidant activities. These findings suggest that Sardina pilchardus may be a potential source of natural antioxidants and ACE inhibitors for the development of functional foods, and using LC-MS/MS in combination with an online database and molecular docking represents a promising, effective, and accurate approach for the discovery of novel ACE inhibitory peptides.

Isolation and identification of angiotensin-converting enzyme inhibitory peptides from Tartary buckwheat albumin.

Tartary buckwheat protein peptides have been shown to be able to inhibit angiotensin-converting enzyme (ACE), but the exact protein type has been less studied for ACE activity inhibition, and only a few types of ACE inhibitory peptides have been reported. In this study, we purified and identified ACE inhibitory peptides from albumin hydrolysate (AH). Albumin, globulin, prolamin and glutelin were extracted from Tartary buckwheat, and their ACE active peptides were obtained by a pepsin-trypsin sequential hydrolysis process. All four hydrolysates exhibited ACE inhibitory activity, and AH displayed the strongest ACE inhibition activity and the highest peptide yield (82.28%). At 0.2 mg mL-1 , the inhibition rate of AH was 79.89%, followed by globulin hydrolysate at 71.84%, while prolamin hydrolysate and glutelin hydrolysate showed lower inhibition rates. The peptides with the highest inhibition rate were then isolated from AH using gel filtration chromatography and reversed-phase high-performance liquid chromatography, and identified using nanoscale high-performance liquid chromatography-tandem mass spectrometry. After isolation and purification, 42 ACE inhibitory peptides were identified in the fraction with the highest inhibition rate, 14 of which were completely novel discoveries in this study. These 14 peptides showed potent ACE inhibitory effects through computer analysis. Tartary buckwheat albumin can be used as a good source of ACE inhibitory peptides and can be further developed and utilized as edible supplements or drugs. © 2023 Society of Chemical Industry.

Angiotensin-Converting Enzyme Inhibition Properties and Antioxidant Effects of Plants and their Bioactive Compounds as Cardioprotective Agent

Background: The prevalence of cardiovascular diseases is being increased; researchers are trying to explore effective preventive and treatment options. Antioxidant effects and AngiotensinConverting Enzyme (ACE) inhibitors demonstrated cardioprotective effects. Many herbs and plants have shown antiinflammatory, antioxidant, free radical scavenging, and ACE inhibition properties in preventing and treating cardiac-related disorders. Therefore, the exploration of bioactive compounds such as polyphenols, flavonoids, quercetin, kaempferol, isoflavones, and catechin needs to be explored as potential ACE inhibitors and antioxidants in preventing and treating cardiac-related diseases Objective: The present study is designed to investigate the cardio-protective potential of important bioactive compounds from plants and herbs. Methods: Articles were collected from electronic databases, such as PubMed, Google Scholar, Web of Science, and Science Direct, using the keywords antioxidant, anti-inflammatory, ACE inhibition and antihypertensive properties of plants and herbs. In vitro and in vivo studies on animal models have been included in the current study. Articles published in languages other than the English language were excluded, and finally, 100 manuscripts were included in this study. Results: Plants and herbs chosen for this study with abundant natural bioactive compounds have demonstrated ACE inhibition, antioxidant, anti-inflammatory, and anti-hypertensive properties and can be an effective cardioprotective. Hence, it could pave the way for the development of new therapeutics that could be beneficial in treating cardiovascular diseases Conclusion: The current review focuses on herbs and plants possessing ACE inhibition, antioxidant, antioxidative, anti-inflammatory, hyperaccumulating and anti-hypertensive properties with their ability to prevent the breakdown of ACE I enzyme into ACE enzyme II, acting as ACE inhibitors and showing its strong potential as a cardioprotective agent. Also, it could support the development of new therapeutic agents to address cardiovascular problems.

Identification of ACE I-Inhibitory Peptides Released by the Hydrolysis of Tub Gurnard (Chelidonichthys lucerna) Skin Proteins and the Impact of Their In Silico Gastrointestinal Digestion.

Tub gurnard is a highly abundant fishery species caught as a discard in the Mediterranean Sea. This work proposes its valorisation through the release of potential antihypertensive peptides and glycosaminoglycans (GAGs) through the controlled hydrolysis of tub gurnard skin proteins. Four proteases (Esperase, Alcalase, Trypsin and Pronase E) were used to obtain potent angiotensin converting enzyme I (ACE)-inhibitory hydrolysates. Peptides and GAGs were separated and evaluated for their antihypertensive potential by fluorometry. The peptide-rich fractions derived from the Esperase and Alcalase hydrolysates showed very low IC50 values (47 and 68 μg/mL, respectively). Only the GAGs from the Trypsin and Esperase hydrolysates were relevant ACE inhibitors (63 and 52% at 1 mg/mL, respectively). The peptide composition of the most potent ACE-inhibitory fractions derived from the Esperase and Alcalase hydrolysates (IC50 values of 33 and 29 μg/mL, respectively) was analysed by RP-LC-ESI-MS/MS. The analysis suggests that the ACE-inhibitory activity is related to the peptide hydrophobicity, as well as to the presence of specific residues at any of the last four C-terminal positions. The in silico gastrointestinal digestion of these fractions yielded small peptides with antihypertensive potential.

Peptidomic analysis of the angiotensin-converting-enzyme inhibitory peptides in milk fermented with Lactobacillus delbrueckii QS306 after ultrahigh pressure treatment

In this study, we assessed the effect of ultrahigh pressure (UHP) treatment on the concentration of peptides and angiotensin-converting enzyme (ACE) inhibitory activity in milk fermented with Lactobacillus delbrueckii QS306. The peptides were identified using peptidomic analysis, and 313 unique peptides were identified. These peptides were derived from 53 precursor proteins. Before and after UHP treatment, 361 (22.2%) peptide sequences exhibited difference, and 53 peptide segments were significantly different. Among them, small peptides (amino acid residues ≤6) isoelectric were point at pH 5–6, and the net charge was mainly positive or neutral. With hydrophobicity and ACE inhibitory activity as screening indicators, 214 small peptides with potential ACE inhibitory activity were identified, and 130 new peptides had potential ACE inhibitory activity. A novel ACE inhibitory peptide VAPFP was synthesized, whose in vitro inhibition rate was 10.56 μmol\\/L. Therefore, using peptidomics, the changes in peptide sequences and enhancement in ACE inhibitory activity before and after UHP treatment could be effectively identified in milk fermented with Lactobacillus delbrueckii QS306. This study provided a convenient method for the discovery and identification of new ACE inhibitory peptides.

Novel antihypertensive peptides from lupin protein hydrolysate: An in-silico identification and molecular docking studies

Application of non-thermal treatment to proteins prior to enzymatic hydrolysis can facilitate the release of novel bioactive peptides (BPs) with unique biological activities. In this study, lupin protein isolate was pre-treated with ultrasound and hydrolysed using alcalase and flavourzyme to produce alcalase hydrolysate (ACT) and flavourzyme hydrolysate(FCT). These hydrolysates were fractionated into 1, 5, and 10 kDa molecular weight fractions using a membrane ultrafiltration technique. The in vitro angiotensin-converting enzyme (ACE) studies revealed that unfractionated ACT (IC50 = 3.21 mg mL−1) and FCT (IC50 = 3.32 mg mL−1) were more active inhibitors of ACE in comparison to their ultrafiltrated fractions with IC50 values ranging from 6.09 to 7.45 mg mL−1. Molecular docking analysis predicted three unique peptides from ACT (AIPPGIPY, SVPGCT, and QGAGG) and FCT (AIPINNPGKL, SGNQGP, and PPGIP) as potential ACE inhibitors. Thus, unique BPs with ACE inhibitory effects might be generated from ultrasonicated lupin protein.

New Insights on Glutathione's Supramolecular Arrangement and Its In Silico Analysis as an Angiotensin-Converting Enzyme Inhibitor.

Angiotensin-converting enzyme (ACE) inhibitors are one of the most active classes for cardiovascular diseases and hypertension treatment. In this regard, developing active and non-toxic ACE inhibitors is still a continuous challenge. Furthermore, the literature survey shows that oxidative stress plays a significant role in the development of hypertension. Herein, glutathione's molecular structure and supramolecular arrangements are evaluated as a potential ACE inhibitor. The tripeptide molecular modeling by density functional theory, the electronic structure by the frontier molecular orbitals, and the molecular electrostatic potential map to understand the biochemical processes inside the cell were analyzed. The supramolecular arrangements were studied by Hirshfeld surfaces, quantum theory of atoms in molecules, and natural bond orbital analyses. They showed distinct patterns of intermolecular interactions in each polymorph, as well as distinct stabilizations of these. Additionally, the molecular docking study presented the interactions between the active site residues of the ACE and glutathione via seven hydrogen bonds. The pharmacophore design indicated that the hydrogen bond acceptors are necessary for the interaction of this ligand with the binding site. The results provide useful information for the development of GSH analogs with higher ACE inhibitor activity.

Structural requirements and interaction mechanisms of ACE inhibitory peptides: molecular simulation and thermodynamics studies on LAPYK and its modified peptides

The understanding of the structural requirements and the intermolecular-interaction mechanism are important for discovering potent angiotensin-converting enzyme (ACE) inhibitory peptides. In this study, we modified an egg-white derived peptide, LAPYK, using the amino acids with different properties to produce the LAPYK-modified peptides. The ACE inhibitory activities of the modified peptides were determined to explore the structural requirements of ACE inhibitory peptides (ACEIPs). Molecular simulation and isothermal titration calorimetry analysis were used to investigate interactions between the peptides and ACE. We found that hydrophobicity and the amino acids with ring structures were beneficial for the ACE inhibitory activities of the peptides. The results of the molecular mechanics poisson boltzmann surface area (MMPBSA) binding free energy calculations indicated that the polar solvation free energy (ΔGpolar) of the charged peptides (LAPYK, LAPYE) were unfavorable for binding to ACE. On the other hand, the results of isothermal titration calorimetry analyses suggested that the enthalpy-driven ACE-peptide interactions were more favorable than the entropy-driven ACE-peptide interaction counterparts.

A Review on Factors and Processing Methods Affecting Antihypertensive Properties of Legumes, and Antihypertensive Properties of Selected Legumes

Hypertension is one of the major risk factors which leads to cardiovascular diseases, and the typical treatment for hypertension is drug therapy. However, as there are side effects to drug therapy, there has been an increase in research on legume proteins as biopeptides have shown antihypertensive effects. Many species of legumes have been cultivated for consumption as they are a good source of protein, carbohydrates, minerals, vitamins, and dietary fiber. Bioactive compounds of legumes potentially improve factors that affect antihypertensive properties, such as angiotensin-converting enzyme (ACE) inhibition activity, renin inhibition activity, and γ-aminobutyric acid (GABA) production. The processing method of enzymatic hydrolysis can improve ACE inhibition activity, as can be seen with horse gram, pigeon pea, and lentil hydrolysates containing potent ACE inhibitory peptides of Thr-Val-Gly-Met-Thr-Ala-Lys-Phe, Val-Val-Ser-Leu-Ser-Ile-Pro-Arg, and Asn-Ser-Leu-Thr-Leu-Pro-Ile-Leu-Arg-Tyr-Leu, while pigeon pea and kidney bean hydrolysates have shown good renin inhibition activity. Fermentation can also be used to process legumes as potent ACE inhibitory peptide Val-Val-Ser-Leu-Ser-Ile-Pro-Arg was identified from fermented pigeon pea, while kidney beans and lentils demonstrated good GABA production through natural fermentation and fermentation with microbial cultures. The germination processing method could also help improve ACE inhibition activity as horse gram has shown good inhibition activity. In vivo study of pigeon pea, kidney bean, and lentils showed potential antihypertensive properties as a significant lowering of systolic blood pressure of test subject was observed. Research done on the structure and function of antihypertensive properties of legumes can help in the development of functional food products which will be beneficial to human health.

Ayçiçek Küspesinden Elde Edilen Protein Hidrolizatlarının Anjiyotensin Dönüştürücü Enzim ve Dipeptidil Peptidaz–IV İnhibisyon Aktiviteleri

In this study, the potential of sunflower protein hydrolysates to inhibit angiotensin converting enzyme (ACE) and dipeptidyl peptidase-IV (DPP-IV) enzyme was determined. Sunflower protein isolate was hydrolyzed with Alcalase and Trypsin+Chymotrypsin enzymes and the obtained protein hydrolysates were fractionated by ultrafiltration (5 kDa). The degrees of hydrolysis achieved by Alcalase and Trypsin+Chymotrypsin enzymes were 27% and 13%, respectively. The most potent ACE inhibitory activity (IC50=0.06 ± 0.01 mg/mL) was observed for the fraction that has molecular weight below 5 kDa, which was hydrolyzed by Trypsin+Chymotrypsin enzyme (P

Determination of perindopril erbumine by oxidative coupling reaction using 2, 6-dichloroquinone-4-chlorimide

Perindopril erbumine (Perindopril tert-butylamine salt) is a potent angiotensin-converting enzyme (ACE) inhibitor. It is used to treat the patients with hypertension and heart failure problems. A sensitive, inexpensive and precise analytical technique has been developed for the estimation of perindopril in bulk and formulations. The procedure involves the development of colour by forming an oxidative coupling reaction between drug (PPE) and reagent such as 2, 6-dichloroquinone-4-chlorimide (DCQC). The formed colored species were measured at (max=520 nm. The developed method showed linearity within the concentration limits of 25-75 μg mL-1. The linear correlation coefficient (r) and molar absorptivity were found to be 0.9999 and 3.285 x 103 mol-1cm-1. % Recovery ± SD values were in the range of 99.69 - 100.51 (+ 0.42 - ( 0.41) (n=3) which indicates the accuracy of the developed method. The interference of other excipients that are commonly present in formulations is found to be negligible. Precision and accuracy of the proposed method were confirmed by student t-test and F-tests at 95% confidence limits with (n-1) degrees of freedom. The validity parameters of proposed method were calculated by ICH guidelines.

Biologically Synthesized Peptides Show Remarkable Inhibition Activity against Angiotensin-Converting Enzyme: A Promising Approach for Peptide Development against Autoimmune Diseases.

Angiotensin-converting enzyme (ACE) regulates several biological functions besides its vital role in immune functions. ACE is elevated in immune cells in inflammatory diseases including atherosclerosis, granuloma, chronic kidney disease, and also autoimmune diseases, like multiple sclerosis, rheumatoid arthritis, and type I diabetes. No significant information prevails in the literature regarding the isolation, identification, and profiling of potential ACE inhibitory peptides. In the present study, indigenous crop varieties like seeds (peanut, corn, oat, sunflower, chickpea, parsley, cottonseed, papaya, sesame, and flaxseed) were used to evaluate their ACE inhibition activity. Variables including hydrolysis time, enzyme-to-substrate ratio (E/S), pH, and temperature were standardized to acquire the most suitable and optimum ACE inhibition activity. Seeds of cotton, chickpea, and peanuts displayed remarkably maximum ACE inhibition activity than other plants. The study disclosed that maximum ACE inhibitory activity (86%) was evaluated from cottonseed at pH 8.0, temperature of 45°C, hydrolysis time of 2 hrs, and enzyme to the substrate (E/S) ratio of 1 : 5 followed by peanuts (76%) and chickpea (55%). SDS-PAGE confirmed that vicilin protein is present in cottonseed and peanut seed while cruciferin and napin proteins are present in chickpeas. LC-MS/MS analysis disclosed potential novel peptides in hydrolyzed cottonseed that can be ascribed as potential ACE inhibitors which have never been reported and studied earlier. The current study further showed that cottonseed peptides due to their promising ACE inhibitory activity can be a valuable source in the field of ACE inhibitor development.