• Proceedings of the PSK Conference
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• 2002.10a
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• pp.383.3-384
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• 2002

Rosmarinic acid (1) and methyl rosmarinic acid (2), isolated from the ethyl acetate soluble fraction of the methanolic extract of Salvia miltiorrhiza Bunge (Lamiaceae) were found to be the tyrosinase inhibitors and scavengers of 1, 1-diphenyl-2-picrylhydrzyl (DPPH) radical. Compounds 1 and 2 inhibited the oxidation of L-tyrosine catalyzed by mushroom tyrosinase with $IC_{50}$/ of 16.8 $\mu\textrm{M}$ and 21.5 $\mu\textrm{M}$. respectively. It compared well with kojic acid. a well-known tyrosinase inhibitor. with an $IC_{50}$ of 22.4 $\mu\textrm{M}$. The inhibitory kinetics, analyzed by a Lineweaver-Burk plot, found rosmarinic acid and its methyl ester to be competitive inhibitors with $K_{i}$ of $2.35{\times}10^{-5}M$ and $1.52{\times}10^{-5}M$ respectively. In addition, compounds 1 and 2 showed the scavenging activities on DPPH radical, with $IC_{50}$ of 4.27 $\mu\textrm{M}$ and 3.05 $\mu\textrm{M}$. respectively. These scavenging effects were more potent than that of L-ascorbic acid ($IC_{50}$ = 11.75$\mu\textrm{M}$).

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.552-558
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• 2002

Polyphenol oxidase from Flammulina velutipes was purified and characterized. Purification of polyphenol oxidase was achieved by ammonium sulfate precipitation, Superdex G-200 gel filtration chromatography, Phenyl superose affinity chromatography, Mono-Q anion exchange chromatography and Superdex S-200 gel filtration chromatography on FPLC. After these purification steps specific activity of purified polyphenol oxidase increased to 199.1 units/mg. Polyphenol oxidase from F. velutipes was composed of a single polypeptide with molecular weight of about 40 kDa. Optimum pH and temperature for the enzyme reaction were found to be 6.0 and $25^{\circ}C$, respectively. The activity of the enzyme gradually decreased at acidic pH between 3 and 5, and the enzyme lost its activity at alkaline pH between 8 and 10. This enzyme exhibited high substrate specificity to o-diphenols. Km-values for L-DOPA and caffeic acid were found to be 3.97 mM and 1.78 mM, respectively. 2-mercaptoethanol, L-ascorbic acid, sodium bisulfite, EDTA and $Mg^{2+}$ inhibited the activity of pholyphenol oxidase and $Cu^{2+}$, $Fe^{2+}$, $Zn^{2+}$ and $Ni^{2+}$ increased enzyme activity. The activity of enzyme was well maintained at $-70^{\circ}C$ for over 4 months, and at $-20^{\circ}C$ for 1 months.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.723-727
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• 2003

The antioxidant activities and their antioxidant compounds of a group of teas obtained in local markets were investigated. A total of 18 teas were tested for their antioxidant activities based on their ability to scavenge ABTS (2,2'-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) cation radical and DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical. The former was expressed as mg of ascorbic acid equivalents per 1 tea bag (L-ascorbic acid equivalent antioxidant capacity, AEAC) and the latter was expressed as percentage of electron donating activity (EDA%). A good correlation of AEAC and EDA was observed between the two methods. The concentrations of total polyphenolics and flavonoids in tea extracts were measured by spectrophotometric methods. Total ascorbic acid was determined via the 2,6-dicholoroindophenol titrimetric method. According to the AEAC value and EDA, black tea, brown rice green tea, green tea, herb tea and malva tea showed relatively high antioxidant activities. Polyphenolic compounds were the major naturally occurring antioxidant compounds found in teas and the high concentrations of polyphenolic compounds were observed in black tea, green tea and herb tea. Overall, six teas out of 18 teas tested in the study showed better antioxidant activities and higher amounts of total polyphenolic compounds.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.1
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• pp.35-41
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• 2013

This study investigated the effect of functional MA films (FMA) incorporated with zeolite powder treated with 1 N HCL solution and anti-fogging agent on the freshness extension of Satsuma mandarin. Preference, weight loss, total ascorbic acid, sugar content, titratable acidity and gas composition in package of Satsuma mandarin were evaluated during storage at $15^{\circ}C$. After 120 days of storage, the weight loss of mandarin packed with LLDPE film (control, L) was 1%, FMA film (CA) was 1.6%. Total ascorbic acid content of Satsuma manderin in control was 19.97 mg%, those of CA was 24.25 mg%. The titratable acidity of Satsuma manderin in CA was higher than that of control, while soluble solids content of CA was lower than that of control after 120 days. Ethylene gas content of control was 89.5 ppm and those of CA was 73.6 ppm after 120 days. Quality of Satsuma mandarin packed with CA was better than that of control. It was verified that shelf-life of Satsuma mandarin in control was 100 days and those of CA film was 130 days. Quality of Satsuma mandarin was few different between treated with anti-fogging agent and non-treated, but commodity of film treated with anti-fogging agent was considered better than that of non-treated.

• The Korea Journal of Herbology
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• v.20 no.4
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• pp.103-112
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• 2005

Objectives : In order to develop effective and safe anti-oxidation, the effects of Menthae Herba (M. spicata L. and M piperita L.) were examined. Methods : M. spicata L. and M. piperita L. of Menthae Herba were used to make water extracts and methanol extracts, and then its anti-oxidative effects were compared in vitro. Results : 1. M. spicata L. was stronger than M. piperita L. in anti-oxidative effects of methanol extracts, and water extracts showed similar anti-oxidation effects. 2. Water extracts of M. spicata L. was stronger than M. piperita L. showed a stronger superoxide anit-oxidation than the same-density ascorbic acid, so that water extracts were proved to be stronger than methanol extracts. 3. Methanol extracts' DPPH anti-oxidation was similar in M. spicata L. and M piperita L.. As for water extracts, M. spicata L. showed higher anti-oxidation and M. piperita L. had no anti-oxidation. 4. As for anti-oxidation of LDL and linoleic acid of methanol extracts, both M. spicata L. and M. piperita L. were stronger than a-tocopherol. As for the water extracts, these two showed similar level of anti-oxidative effect on linoleic acid, which is weaker that mehtanol extracts. 5. M. spicata L. includes more phenol than M. piperita L. Conclusions : Menthae Herba (M. piperita L. M. spicata L.) had anti-oxidation effect, so that it can be medically developed for anti-oxidation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1122-1129
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• 2016

In this study, bioactive constituents and biological activities of aronia, blackcurrant, and maquiberry were investigated. The 60% ethanol extracts were prepared and evaluated for total polyphenol, total flavonoid, and total anthocyanin contents. Biological activities, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities, ferric reducing antioxidant power (FRAP), reducing power, tyrosinase inhibitory activity, and nitrite scavenging activity were also examined. Maquiberry showed the highest bioactive constituents as shown based on total polyphenol (73.66 mg GAE/g), total flavonoid (28.08 mg/g), and total anthocyanin (12.82 mg/g) contents compared to aronia and blackcurrant. Maquiberry also exhibited the highest DPPH and ABTS radical scavenging activity, FRAP, and reducing power at a concentration of 5 mg/mL, which were superior to those of ascorbic acid (a positive control). Therefore, maquiberry could be used as a potential source of antioxidants and functional food substances.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1248-1254
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• 1997

To measure antioxidative activities, the various extracts from RVS (Rhus Verniciflua Stokes) were tried out with either DPPH or thiocyanate method. Also we used the GO (Glucose Oxidase) 20 mU/mL hydroxyl radical system in mouse whole brain cell culture. Chloroform, n-hexane or ethanol were used as extract solutions which had different polarity respectively. In DPPH and thiocyanate method, the antioxidative activities of the crude ethanol extracts were stronger than other extracts. The crude ethanol extracts were fractionated 5 peaks by glass column. Among of them, antioxidative activity of peak II $(P_{II})$ was shown stronger than other fractions, a little for peak III $(P_{III})$ and peak IV $(P_{IV})$, and none for peak I $(P_I)$ and Peak V $(P_V)$. In the antioxidative effects of crude ethanol extracts (30 mg/mL), cell viabilities were evaluated $1\;{\mu}L\;(297\;{\mu}g/mL)$, $2\;{\mu}L\;(588\;{\mu}g/mL)$ of crude ethanol extracts 59%, 68% respectively. $10\;{\mu}L\;(2,727\;{\mu}g/mL)$ addition of crude ethanol extracts had 95% cell viabilities, 0.01% significant, comparing control. In addition, the compounds related to antioxidative effect of crude ethanol extract might be glycoproteins by means of SDS-PAGE. Comparison to antioxidative effects between several antioxidants (ascorbic acid, ${\alpha}-tocopherol$, catalase) $273\;{\mu}L/mL$ addition of crude ethanol extracts corresponds to $1\;{\mu}g/mL$ catalase in antioxidative effects.

• Applied Biological Chemistry
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• v.45 no.4
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• pp.218-222
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• 2002

Lycii Cordex Radicis extract (gigolpi) examined through SOS Chromotest showed a strong, dose-dependent antimutagenic effect on the tert-butyl hydroperoxide (t-BOOH) induced mutagenecity. Gigolpi revealed considerable superoxide anion radical scavenging activity under L-ascorbic $acid-CuSO_4$ system, but showed lower hydroxyl radical scavenging activity in photochemical test system. Hot-water gigolpi extract delayed protein oxidation, whereas lipid peroxidation of rat skin exposed to UVB radiation was inhibited. The results indicate that gigolpi possessing antioxidant activity against UVB-induced lipid peroxidation could be used as a raw ingredient for manufacturing functional cosmetics

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.5
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• pp.469-475
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• 1987

The present paper was investigated to elucidate the nitrite-scavenging ability of seaweed extracts. Seaweed extracts possessed the scavenging ability of nitrite. By fractionation of seaweed extracts, nitrite-scavenging ability of laver(Porphyra tenera), sea lettuce(Enteromorpha compresa) extracts were effective in the water-soluble fraction, but sea mustard (Undaria pinnatifida), sea staghorn (Codium fragile) extracts in the methanol-soluble fraction. Nitrite scavenging ability of seaweed extracts was also pH-dependent, highest at pH1.2 and lowest at pH6.0. Particularly, nitrite-scavenging abilities of water-soluble fractions obtained from laver and sea lettuce were similar to that of L-ascorbic acid at pHl.2. After seaweed extracts were treated with sodium borohydride, nitrite-scavenging ability was remarkably decreased at pH1.2. It is assumed that reducing powers of seaweed extracts participated in their nitrite-scavenging abilities.

• KSBB Journal
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• v.18 no.3
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• pp.165-169
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• 2003

The antioxidative activity of Portulaca oleracea was tested using in vitro experimental models. Antioxidative activities were determined by measuring DPPH radical scavenging activity and lipid peroxide using 2-thiobarbituric and (TBA). The crude extract was sequentially partitioned with n-hexane, 15% aq. MeOH, EtOAc, n-BuOH, $H_2O$. A remarkable antioxidative effect was observed in the EtOAc and n-BuOH fractions. The DPPH radical scavenging effect ($IC_{50}$=17.90 $\mu\textrm{g}$/ml) of the n-BuOH soluble fraction was comparable with that of the natural antioxidant, $\alpha$-tocopherol ($IC_{50}$=6.99 $\mu\textrm{g}$/ml) and the inhibition effect of lipid peroxidation in mouse liver homogenate was similar to that of the natural antioxidant, L-ascorbic acid at a concentration of 1.0 mg/ml to 5 mg/ml.