• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.59-64
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• 2002

An angiotensin I-converting enzyme (EC 3.4.15.1) (ACE), which can convert inactive angiotensin I into angiotensin II, a vasoconstrictor, is one of the key enzymes in controlling hypertension. It is suggested that the inhibition of ACE prevents hypertension, and many inhibitory peptides have already been reported. In the current study, oligonucleotides encoding ACE inhibitory peptides (IY, VKY) were chemically synthesized and designed to be multimerised due to isoschizomer sites (BamHI, BglII). The cloned gene named AP3 was multimerised up to 6 times in pBluescript and expressed in BL2l containing pGEX-KG. The fusion protein (GST-AP3) was easily purified with a high recovery by an affinity resin, yielding 38 mg of synthetic AP3 from a 1-1 culture. The digestion of AP3 by chymotrypsin exhibited an $IC_50$ value of $18.53{\mu}M$. In conclusion, the present experiment indicated that AP3 could be used as a dietary antihypertensive drug, since the potent ACE inhibitory activity of AP3 could be activated by chymotrypsin in human intestine.

• Food Science of Animal Resources
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• v.43 no.1
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• pp.46-60
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• 2023

Slaughterhouse blood is a by-product of animal slaughter that can be a good source of animal protein. This research purposed to examine the functional qualities of the blood plasma from Hanwoo cattle, black goat, and their hydrolysates. Part of the plasma was hydrolyzed with proteolytic enzymes (Bacillus protease, papain, thermolysin, elastase, and α-chymotrypsin) to yield bioactive peptides under optimum conditions. The levels of hydrolysates were evaluated by 15% sodium dodecyl sulfate polyacrylamide gel electrophoresis. The antioxidant, metal-chelating, and angiotensin I-converting enzyme (ACE) inhibitory properties of intact blood plasma and selected hydrolysates were investigated. Accordingly, two plasma hydrolysates by protease (pH 6.5/55℃/3 h) and thermolysin (pH 7.5/37℃/3-6 h) were selected for analysis of their functional properties. In the oil model system, only goat blood plasma had lower levels of thiobarbituric acid reactive substances than the control. The diphenyl picrylhydrazyl radical scavenging activity was higher in cattle and goat plasma than in proteolytic hydrolysates. Ironchelating activities increased after proteolytic degradation except for protease-treated cattle blood. Copper-chelating activity was excellent in all test samples except for the original bovine plasma. As for ACE inhibition, only non-hydrolyzed goat plasma and its hydrolysates by thermolysin showed ACE inhibitory activity (9.86±5.03% and 21.77±3.74%). In conclusion, goat plasma without hydrolyzation and its hydrolysates can be a good source of bioactive compounds with functional characteristics, whereas cattle plasma has a relatively low value. Further studies on the molecular structure of these compounds are needed with more suitable enzyme combinations.

• Korean Journal of Medicinal Crop Science
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• v.12 no.1
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• pp.73-78
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• 2004

The study was conducted to develop new materials of functional foods from natural resources. Fortyeight medicinal plants were screened on inhibitory activity of angiotensin-converting enzyme (ACE), a protein elevating blood pressure. The water extracts of Armoracia aerial part, Cynanchum radix, Euonymus branch, Phyllostachys stem, Trichosanthes seed, and methanol extract of Silybum aerial part were showed strong inhibitory activity (above 70%) on ACE at the final concentration of $4,000\;{\mu}g\;ml^{-1}$. Among the plant extracts, water extracts of Phyllostachys taeniam and Trichosanthes seed were especially showed strong inhibitory activity (above 25%) at $500\;{\mu}g\;ml^{-1}$. These two plants are expected good candidate for development into anti-hypertensive materials.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.4
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• pp.219-225
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• 2005

We studied the anticancer, antioxidative, ACE inhibitory, antithrombic, and cerebral ischemia inhibitory activities, of low molecular weight substances fractionated from the seasoned and smoked products of skipjack tuna (Euthynus pelamis). Low molecular weight substances fractionated from the liquid extract of seasoned and smoked skipjack tuna powder showed 7 peaks on gel permeation chromatography. Anticancer activity was the highest at Peak 3 $(54.23%)$ followed by Peak 4 $(41.58\%)$. The potency order of antioxidative activity was the highest at Peak 3 $(94.14\%)$ followed by Peak 2 $(82.07\%)$ and Peak 5 $(81.24\%)$. ACE inhibitory activity was the highest at Peak 3 $(67.27\%)$ followed by Peak 5 $(45.62\%)$. But there was weak anti thrombotic effect (PT and APTT) in the low molecular weight substances of the seasoned and smoked products of skipjack tuna. Cerebral ischemia inhibitory activity was the highest at Peak 3 $(80.0\%)$ followed by Peak 5 $(40.0\%)$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.421-427
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• 2010

To isolate natural antihypertensive substances from edible seaweeds, we screened for and separated active compounds contained in natural Underia pinnatifida, cultural Underia pinnatifida, Laminaria japonica, Sporophylls and Agarum cribrosum. They were extracted using room temperature water, boiling water, acetone, and methanol in turn or using room temperature water, ether, acetone, methanol and boiling water in order. The in vitro antihypertensive activity was quantified as inhibitory efficacy against angiotensin-I converting enzyme (ACE), which is a factor inducing hypertension. For all of the seaweeds tested, the fractions soluble in room temperature water and in boiling water showed the strongest ACE inhibitory effect among the extracted fractions. Conversely, the methanol-extracted fractions for all of the seaweeds tested showed no antihypertensive activity. While the ether and acetone fractions had slight antihypertensive effects. The compounds in the aqueous extracts that had antihypertensive activity were presumed to be polysaccharides, such as fucoidan and alginate.

• Journal of Dairy Science and Biotechnology
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• v.41 no.2
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• pp.45-56
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• 2023

This review serves two purposes: first, to promote the use of improved optimization techniques in response surface methodology (RSM); and second, to enhance the optimum conditions for the fermentation of probiotics. According to research in dairy science, Lactiplantibacillus plantarum K79 is a candidate probiotic that has beneficial health effects, such as lowering blood pressure. The optimum conditions for L. plantarumK79 to produce peptides with angiotensin-converting enzyme (ACE) inhibitory activity were proposed, through modeling each of ACE inhibitory activity and pH as a function of the four factors that are skim milk concentration (%), incubation temperature (℃), incubation time (hours), and starter added amount (%). To estimate optimum conditions, the researchers employed a desirability-based multi-response optimization approach, utilizing third-order models with a nonsignificant lack of fit. The estimated optimum fermentation conditions for L. plantarum K79 were as follows: a skim milk concentration of 10.76%, an incubation temperature of 36.9℃, an incubation time of 23.76 hours, and a starter added amount of 0.098%. Under these conditions, the predicted ACE inhibitory activity was 91.047%, and the predicted pH was 4.6. These predicted values achieved the objectives of the multi-response optimization in this study.

• Applied Biological Chemistry
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• v.49 no.2
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• pp.114-124
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• 2006

The objective of this research was to evaluate the ability of water and 80% ethanol extracts from one hundred eight mulberry leaves (Morus alba L.) to influence the inhibitory activity of angiotensin converting enzyme (ACE) and xanthine oxidase (XOase). The total phenol contents were that water extracts of ten species (Kakjayongsan (Morus alba L.), Daejungsun (Morus alba L.) etc.) and 80% ethanol extracts of twenty three species (Waryoung (Morus alba L.), Hasusang (Morus alba L.) etc.) showed more than 15 mg/g. The inhibitory activity on angiotensin converting enzyme (ACE) were that ten species (YamanakkadakKaskke (Morus alba L.), Mijiro (Morus alba L.) etc.) showed 100% inhibition rate both of water extracts and 80% ethanol extracts. The rest, water extracts of thirty four species (Cheongilppong (Morus alba L.) etc.) and 80% ethanol extracts of thirty four species (Wonjukojo (Morus alba L.) etc.) showed inhibitory activity (above 90%) on ACE. Also, to search of xanthine oxidase (XOase) inhibition were that water extracts of five species (Cheongsipjosaeng (Morus alba L.), Suwon 3 (Morus alba L.) etc.) and 80% ethanol extracts of Jeokmok (Morus alba L.) showed inhibitory activity (above 50%) on XOase. This result revealed, strong biological activity in spite of has a little total phenol contents. These water and 80% ethanol extracts from mulberry leaves (Morus alba L.) are expected good candidate for development into anti-hypertentive and anti-gout sources.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.10
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• pp.1538-1542
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• 2015

For development of premium sauce, fermented sauces containing ferment (with wheat flour and soybean) and extract(s) of Styela clava (Korean name: miduduk) tunic and/or mulberry leaves and/or onion were prepared, and their angiotensin converting enzyme (ACE) inhibitory and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities were evaluated. All sauces containing extract(s) showed increased ACE inhibitory and DPPH radical scavenging activities. Especially, sauces containing extracts of mulberry leaves and onion showed superior activities, with 26.92% and 40.66% relatively increased ACE inhibitory and DPPH radical scavenging activities, respectively, compared to control (no extract was added). These results suggest that extracts of mulberry leaves and onion could improve antihypertensive and antioxidant activities of fermented sauce.

• Food Science of Animal Resources
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• v.31 no.5
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• pp.663-667
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• 2011

This study was performed to measure the angiotensin I-converting enzyme (ACE) inhibitory activity of peptide extracts derived from the enzymatic proteolysis of Hanwoo Musculus longissimus (M. longissimus) during cold storage. Thermolysin (80 ppm, w/w) and protease type XIII (100 ppm, w/w) were injected separately or in combination for the enzymatic proteolysis of sarcoplasmic and myofibrillar proteins prior to storage at $5^{\circ}C$ (T1) or at $-1^{\circ}C$ (T2) in a chilling room for 9 days. Beef injected with thermolysin (E2) and thermolysin+protease type XIII (E3) showed a significantly higher degree of hydrolysis at both storage temperatures (p<0.05). During the storage period, T1E2 at day 6 and T1E3 at day 9 showed the strongest ACE inhibitory activity with sarcoplasmic and myofibrillar protein proteolysates. Macromolecules greater than 10,000 Da were removed by ultra filtration, and the filtrates were separated into fractions using gel filtration. Five and three major fractions were collected from S-T1E2-6 and M-T1E3-9 extracts, respectively, and the $4^{th}$ fraction of the S-T1E2-6 extracts showed the highest ACE inhibitory rate of $61.96{\pm}7.41%$.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.183-184
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• 2001

Angiotensin I converting enzyme (ACE) in renin-angiotensin system is a cause of essential hypertension, which covers most hypertension, one of the major adult diseases. Thus, the inhibition of ACE would be indispensable for the prevention and cure of hypertension. Therefore, a lot of studies on the ACE inhibitor have been conducted. Peptides from the protein hydrolysate have been reported as an remarkable inhibitor. Especially, various ACE inhibitory peptides were isolated and identified from marine products for their utilization as value added products. (omitted)