• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.5
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• pp.529-533
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• 2002

The peptides inhibiting angiotensin converting enzyme (ACE) were isolated from the hydrolysate of manila clam (Ruditapes philippinamm) proteins prepared with thermolysin. The thermolysin hydrolysate was pretreated with membrane filter (MW cut-off 10,000) to obtain the peptide fraction with ACE inhibition. The crude peptides were applied to a Sephadex LH-20 column and eluted with $30\%$ methanol. The three active fractions (A, B and C) were collected and concentrated, and then applied to a SP-Toyopearl 650S column equilibrated with distilled water and was eluted with a linear gradient of NaCl concentration (0 to 1 M). The four active fractions (A-1, A-2, B-1 and C-1) were collected and concentrated, and then applied to a SuperQ-Toyopearl 650S column equilibrated with distilled water and was eluted with a linear gradient of NaCl concentration (0 to 1 M). The maximum inhibitory activity was observed in the fraction B-1Q showed the IC_{50} values of 0.748 $\mu$g. The abundant amino acids obtained from active fraction B-1Q were leucine, isoleucine, alanine and threonine.

• Food Science and Preservation
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• v.16 no.5
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• pp.734-741
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• 2009

Response surface methodology (RSM) was used to optimize extraction conditions for functional components of buckwheat (Fagopyrum esculentum). A central composite design was applied to investigate the effects of three independent variables, namelyextraction temperature (X1), extraction time (X2), and ethanol concentration (X3), on responses including extraction yield (Y1), total phenolic content in the extract (Y2), $\alpha$-glucosidase inhibition activity (Y3), and acetylcholine esterase (ACE) inhibition activity (Y4). Data were analyzed using an expert design strategy and statistical software. The maximum yield was 24.95% (w/w) at $55.75^{\circ}C$ extraction temperature, 8.75 hextraction time, and 15.65% (v/v) ethanol. The maximum total phenolic yield was 222.45 mg/100 g under the conditions of $28.11^{\circ}C$ extraction temperature, 8.65 h extraction time, and 81.72% (v/v) ethanol. The maximum $\alpha$-glucosidase inhibition activity was 85.38% at $9.62^{\circ}C$, 7.86 h, and 57.58% (v/v) ethanol. The maximum ACE inhibition activity was 86.91% under extraction conditions of $10.12^{\circ}C$, 4.86 h, and 44.44% (v/v) ethanol. Based on superimposition of a four-dimensional RSM with respect to levels of total phenolics, $\alpha$-glucosidase inhibition activity, and ACE inhibition activity, obtained under various extraction conditions, the optimum ranges of conditions were an extraction temperature of $0-70^{\circ}C$, an extraction time of 2-8 h, and an ethanol concentration of 30-80% (v/v).

• Mycobiology
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• v.33 no.3
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• pp.142-146
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• 2005

To produce a novel antihypertensive angiotensin I-converting enzyme (ACE) inhibitor from yeast, a yeast isolate, designated G-14 showing the highest ACE inhibitory activity was obtained and identified as Malassezia pachydermatis based on morphological, biochemical and cultural characteristics. The maximal extracellular ACE inhibitor production was obtained from M. pachydermatis G-14 when the strain was cultured in YEPD medium containing 0.5% yeast extract, 3.0% peptone and 2.0% glucose at $30^{\circ}C$ for 24 h and the final ACE inhibitory activity was 48.9% under the above condition.

• Microbiology and Biotechnology Letters
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• v.23 no.4
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• pp.439-445
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• 1995

Identification of Actinomycetes isolate strain SH-8002, a producer of ACE inhibitor, based on procedures employed in the international Streptomyces project. The strain, designated as SH-8002, was identified as Streptomyces zoamyceticus SH-8002 based on its morphological, physiological, biochemical and chemotaxonomic characteristics. The ACE inhibitor produced by the strain was highly achieved in fermentation medium condition that was 1% soluble starch, 0.5% tryptone, 0.2% K$_{2}$HPO$_{4}$, 0.2% CaCO$_{3}$, 0.1% NaCl, pH 8.0 at 30$\circ$C for 144 hrs.

• Korean Journal of Medicinal Crop Science
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• v.11 no.3
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• pp.236-245
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• 2003

The study was performed for elucidating angiotensin converting enzyme (ACE) inhibitory activity and comparing antioxidative activity of Panax ginseng extracts prepared at different conditions. Total phenolic content, inhibitory activity on ACE and antioxidative effects were tested on 10 ethanolic extracts and correlation coefficient between total phenolic content and physiological activity was calculated. Yield and total phenolic content of 50% ethanolic extract prepared at $85^{\circ}C$ exhibited the highest value as 42.52% and 0.82%, respectively. Among the fractions obtained from 50% ethanolic extract prepared at room temperature, water fraction showed the highest value in yield as 72.08% and ethyl acetate fraction did in total phenolic content as 6.59%. In the test on ACE inhibitory activity, 50% ethanolic extract obtained at room temperature indicated the strongest effect of 93.8% which was higher than 85.2% of commercialized ACE inhibitor and solvent fractions showed potent inhibitory activity in order of hexane fraction, diethyl ether fraction, ethyl acetate fraction, butanol fraction and water fraction at concentration of $4000{\mu}g/ml$. 50% Ethanolic extract prepared at $85^{\circ}C$ had the most potent inhibition effect on human LDL oxidation as 78.2% at $200{\mu}g/ml$ and the other extracts also did above 60%. Diethyl ether fraction and ethyl acetate fraction showed strong inhibition activity $(34.38%{\sim}78.13%)$ on LDL oxidation at concentration of $10{\sim}200\;{\mu}g/ml$. From the statistical analysis via SAS program, correlation coefficient between total phenolic content and ACE inhibitory effect was 0.6353 at P<0.05. Conclusively, this report showed that the most efficient extraction condition for elevating inhibitory activity on ACE and LDL oxidation, phenolic content and yield from Panax ginseng was 50% ethanol extraction at room temperature or high temperature condition. And Panax ginseng would be used for preventing hypertension or atheroscrelosis for man via inhibitory action on ACE and LDL oxidation.

• Food Science and Biotechnology
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• v.27 no.6
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• pp.1781-1789
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• 2018

In this study, whey proteins were fermented with 34 lactic acid bacteria for 48 h at $37^{\circ}C$ and their ability to inhibit angiotensin 1-converting enzyme (ACE) activity were compared. All the lactic acid bacteria displayed varying proteolytic abilities in whey. Their fermentates also displayed varying abilities to inhibit ACE in vitro. Seven fermentates showed strong ACE inhibitory abilities between $84.70{\pm}0.67$ and $52.40{\pm}2.1%$ with $IC_{50}$ values between $19.78{\pm}1.73$ and $2.13{\pm}0.7mg/ml$. Pediococcus acidilactici SDL1414 showed the strongest ACE inhibitory activity of $84.7{\pm}0.67%$ ($IC_{50}=19.78{\pm}1.73{\mu}g/ml$). Mass spectrometry revealed that more than half (57.7%) of the low molecular weight peptides (< 7 kDa) in the P. acidilactici SDL1414 fermented samples were ACE inhibitory peptides. Our results show that P. acidilactici SDL1414 could be used as a starter culture in the dairy industry to develop antihypertensive functional foods for hypertension management.

• Journal of Animal Science and Technology
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• v.45 no.2
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• pp.319-326
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• 2003

Angiotensin-I converting enzyme(ACE)inhibitor was isolated from beef by-products. The beef by- product hydrolysates prepared with various proteases were tested for the inhibitory effects against ACE. The proteases used were proteinase A from bakers yeast, protease type ⅩIII fungal and thermolysin. The maximum inhibitory effect was observed after hydrolysis for 12hrs(beef heart) and 24hrs(beef spleen), respectively. After gel filtration, IC50 value was 0.37mg/ml in beef heart and 1.84mg/ml in beef spleen. After RP-HPLC, the IC50 value of peak 1, peak 2, peak 3 and peak-4 were 0.28mg/ml, 0.26mg/ml, 0.25mg/ml and 0.35mg/ml, respectively. In the results of amino acid composition of peak 1, peak 2, peak 3 and peak 4, it was observed that peak 1 was consisted mainly of glycine and methionine, peak 2 was proline, cystine and methionine, peak 3 was proline and peak 4 was alanine, methionine and leucine. In conclusion, beef heart hydrolysate treated with thermolysin+ proteinase A was shown to have the highest inhibitory effect for 12hrs incubation at 37$^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.775-783
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• 1997

Morphologically different 18 strains were isolated and examined for their abilities to inhibit ACE. Those strains were cultured in the medium containing 10% of soybean extract at 37$^{\circ}C$ for 48hr or fermented with boiled soybean at 3$0^{\circ}C$ for 60 days. The concentration of inhibitors to inhibit 50% of ACE activity, $IC_{50}$ was measured on the culture broth of each strain and also on the hot-water extract from 20, 40 and 60 day fermented Doenjang by each strain. As a result, SCB-3 which is isolated from Meju showed the highest ACE inhibitoryactivity on the cultured broth and 40 day matured Doenjang. Then, $IC_{50}$ of SCB-3 was 0.02 mg/ml and 0.26mg/ml respectively. SCB-3 was identified as a Bacillus subtilis based upon its morphological, biochemical and physiological properties. Changes in general components and ACE inhibitory activity of Doenjang fermented by SCB-3 were examined during 90 days. Total acidity of Doenjang was increased from 1.39% to 1.66% and pH was decreased from 6.02 to 5.79 after 90 days fermentation. Total sugar contents were decreased from 16.4% to 15.1% and reducing sugar contents was also decreased from 2.45% to 1.62%. Total nitrogen contents were nearly not changed, but amino nitrogen contents were drastically increased from 196mg% to 541mg%. The numbers of total microorganism were increased to 1.1$\times$$10^{8}$ cells/g after 45 days. Protease activity was increased to 622.1U/g after 75 days. The highest ACE inhibitory activity was shown in 60 day fermented Doenjang and $IC_{50}$ of the hot-water extract was 0.31mg/ml.

• KSBB Journal
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• v.16 no.2
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• pp.158-162
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• 2001

A halotolerant and extracellular protease-producing yeast was isolated from traditional Meju and identified as a strain of Hansenular polymorpha by investigating its microbiological characteristics. The optimum pH, temperature and NaCl concentration reauired for the growth of Hansenular polymorpha S-9 were found to be pH 6.0, 30$^{\circ}C$ and 0.5 M, respectively. Extracellular protease was produced maximally at 10 U ml(sup)-1 when Hansenular polymorpha S-9 was grown on the medium containing 1.0% beef extract and 0.1 M NaCl for 12 hr at 30$^{\circ}C$. About 13% of the angiotensin-converting enzyme (ACE) inhibitory activity was shown in the hydrolysates which were obtained from the digestion of soybean protein (6 mg) for 6 hr at 30$^{\circ}C$ by the crude enzyme (1 U).

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.6
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• pp.1195-1204
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• 1992

The natural convection from upward and downward facing horizontal isothermal plate immersed in water is studied numerically. The temperature of the plate is from 0.0 .deg. C to 8.0 .deg. C and the ambient water temperature is from 1.0 .deg. C to 10.0 .deg. C. Numerical results are presented for the velocity profiles, temperature profiles, local heat transfer coefficients, and average Nusselt numbers over the entire flow fields. Flow patterns are shown in the upward and downward facing surfaces at different ambient water temperatures. For the upward facing surface, there are upflow and unsteady flow. And the regions of the ambient water temperatures which give rise to the upflow are more extensive as the temperatures of the isothermal surface become more distant from the density extremum temperature. For the downward facing surface, only the downflow region is shown. For the upward facing horizontal isothermal surface, the average Nusselt number(= N $u_{1}$$^{*}$) is 28.86(Ra)$^{0.01}$. And for the downward facing surface, the average Nusselt number(= N $u_{2}$$^{*}$) is $C_{2}$(Ra)$^{0.2}$ and the values of $C_{2}$ are enlarged in the range of 0.785 .leq. $C_{2}$ .leq. 1.250 as increasing of the temperatures of the isothermal surface.ace.ace.