• Natural Product Sciences
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• v.14 no.3
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• pp.177-181
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• 2008

Five polyacetylenes, ginsenoyne K (1), (Z)-1-methoxyheptadeca-9-en-4,6-diyne-3-one (2), panaxydol (3), panaxydiol (4), and (E)-heptadeca-8-en-4,6-diyne-3,10-diol (5) were isolated from the adventitious roots of Panax ginseng and their chemical structurFive polyacetylenes, ginsenoyne K (1), (Z)-1-methoxyheptadeca-9-en-4,6-diyne-3-one (2), panaxydol (3), panaxydiol (4), and (E)-heptadeca-8-en-4,6-diyne-3,10-diol (5) were isolated from the adventitious roots of Panax ginseng and their chemical structures were elucidated by interpretation of spectroscopic data. Among the isolated compounds, compounds 2 and 5 were reported for the first time as a natural product. Ginsenoyne K (1) showed dose-dependent inhibitory effect on dopa oxidase activity of tyrosinase.es were elucidated by interpretation of spectroscopic data. Among the isolated compounds, compounds 2 and 5 were reported for the first time as a natural product. Ginsenoyne K (1) showed dose-dependent inhibitory effect on dopa oxidase activity of tyrosinase.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.187-195
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• 2008

Polyphenol oxidase (PPO) is implicated in discoloration of white salted noodles and other wheat based foods. PPO activity was evaluated to determine the effect on discoloration of noodle dough sheets prepared from 25 Korean wheat flours during storage and to screen experimental lines with low PPO activity in 52 Korean wheats. PPO activity was assayed with whole-seed and performed with L-dihydroxyphenylalanine (L-DOPA) as substrates. Absorbance by L-DOPA assay of 25 Korean wheats was from 0.285 to 1.368 at 475 nm. PPO activity was significantly related with grain characteristics, including 1000-kernel weight and grain colors. In flour characteristics, PPO activity positively correlated with ash and protein content (r = 0.658, P < 0.001 and r = 0.424, P < 0.05, respectively) and negatively correlated with $L^*$ value of flour (r = 0.412, P < 0.05). In the changes of color of noodle dough sheet, $L^*$ and $b^*$ values consistently decreased and $a^*$ value increased during storage. PPO activity negatively correlated with $L^*$ value of noodle dough sheet during storage (r = 0.566, P < 0.01 at 2 hr, r = 0.547, P < 0.01 at 24 hr, and r = 0.509, P < 0.01 at 48 hr). But, no significant relationship was found in between PPO activity, $a^*$ and $b^*$ values during storage. The 52 Korean wheat lines examined in this study were divided into 3 different groups, low (< 0.500), medium (0.501-0.999) and high level (> 1.000), on the basis of the level of PPO activity. Twenty two Korean wheat lines showed low level of PPO activity and Suwon 252, 277 and 280 showed lower PPO activity (< 0.200) than others.

• Food Science and Preservation
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• v.12 no.5
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• pp.489-495
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• 2005

Polyphenol oxidase (PPO) from Burdock (Arctium lappa L.) was purified and characterized. Purification of polyphenol oxidase was achieved by ammonium sulfate precipitation, Phenyl-sepharose CL-4B hydrophobic chromatography and Sephadex G-100 gel filtration chromatography. The molecular mass of the purified PPO was estimated to be 30 kDa by SDS polyacrylamide gel electrophoresis. In a substrate specificity, maximum activity was achieved with chlorogenic acid, followed by catechol and catechin. Whereas, there was low activity with hydroquinic acid, resorcinol or tyrosine. The optimum pH and temperature for enzyme activity were 7.0 and 35$\circC$ with catechol, respectively. The enzyme was most stable at pH 7.0 while unstable at acidic and alkaline pH. The enzyme was stable when heated to 40$\circC$. But heating at 50$\circC$ for more than 30 min caused 50% loss of activity. Ascorbic acid, L-cystein and $Cu^{2+}$ inhibited the activity of pholyphenol oxidase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.1013-1016
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• 2004

The inhibitory effect of MRPs (Maillard reaction products) on enzymatic browning of taro was investigated. The MRPs prepared by heating glycine and glucose at 9$0^{\circ}C$ for 7 hr exhibited a strong inhibitory effect on taro polyphenol oxidase (PPO). The maximum inhibitory activity of MRPs against taro PPO was detected toward (＋)-catechin, catechol, 4-methylcatechol followed by L-$\beta$-3,4-dihydroxyphenylalanine (L-DOPA) and pyragallol as a substrate. The MRPs synthesized from fructose and glucose with glycine as a amino acid significantly reduced the taro PPO activity. MRPs prepared by higher glycine or glucose concentration showed stronger inhibition against taro PPO. Increasing reaction time of the glycine and glucose promoted the inhibitory effect of MRPs against the PPO activity of taro, whereas the color formation was gradually increased.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.111-116
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• 1996

Polyphenol oxidase(PPO) isolated from the crude extract of ascidian, Halocynthia roretzi, showed higher affinity for catechol than tyrosine or DL-DOPA. Successful enzyme assay could be performed at $25^{\circ}C$, 10min. by mixing 0.2ml of crude enzyme extract with 2.8ml of 0.13M catechol in 0.1M sodium phosphate buffer(pH 6.4). The specific activity of PPO which had been purified with a combination of ammonium sulfate treatment, ion exchange chromatography on DEAE-cellulose, and gel filtration on Sepharose 6B was 13-fold disc gel electrophoresis. The activity of PPO was stable from pH 5.0 to 8.0 and showed the peak activity at pH 6.4 .The optimum reaction temperature for PPO oxidation on catechol was 35$^{\circ}C$ and those enzyme were heat stable up to 4$0^{\circ}C$. Molecular weigth of the enzyme was estimated about 170kDa. One molecule was found to be composed of gour subunits. Two of them had molecular weigh of 55kDa and the others 30kDa. The {TEX}$K_{m}${/TEX} values, {TEX}$V_{max}${/TEX} and catalytic efficiency({TEX}$V_{max}${/TEX}/{TEX}$K_{m}${/TEX}) for catechol were 0.12mM, 2.5mM/liter/min. and {TEX}$0.18min^{-1}${/TEX} respectively. The substrate affinity and electrophorectic pattern suggested that the enzyme of ascidian was considered to be not tyosine but catechol oxidase.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.4
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• pp.287-301
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• 2008

In order to develop a new depigmenting agent, extracts were obtained from 60 native plants and their antimelanogenic activities were screened by evaluating the inhibitory effect on tyrosinase which is a major enzyme responsibles for the melanin synthesis. The extracts of Trichosanthes kirilowii fruits, Phyllostachys bambusoides inner films (BIF), Clerodendrum trichotomum leaves, and Acer okamotoanum leaves showed relatively high inhibitory effect on tyrosinase and their $IC_{50}$ values were $50{\sim}100{\mu}g/mL$. The extract of BIF inhibited melanin synthesis of B16F10 melanoma cells by 52%, which was the highest among those of various extracts. Furthermore, the effect of BIF extract is 10% higher than that of arbutin (42%), a popular depigmenting agent in Korea. Ten compounds having antimelanogenic activity were isolated from the BIF extract by solvent extraction and chromatography. These compounds were identified as phenolic derivatives: SM701, SM702, SM703, and BPR211 were hydroquinone derivatives; SM707 a gallic acid derivative; SM704, SM705, SM706, SM708 and SM709 ferulic acid derivatives. The free radical scavenging activities of these compounds were measured and compared to those of hydroquinone and vitamin C. The $SC_{50}$ values scavenging 50% DPPH of SM702 and SM709 were $60{\sim}70{\mu}M$ similar to that of hydroquinone and those of SM701 and SM708 were $30{\sim}40{\mu}M$ slightly lower than that of vitamin C. These results suggest the presence of components having high antioxidant activity in the BIF extract. The SM709, identified as 1,2-O-diferulylglycerol, inhibited the activities of tyrosine hydroxylase and dopa oxidase by 18 and 60%, respectively. The SM709 also inhibited the melanin synthesis of B16F10 melanoma cells by 62% and this was the highest antimelanogenic activity among those obtained from the various purified compounds. Therefore, antimelanogenic activity of the BIF extract was concluded to be due to both inhibition of DOPA oxidase and antioxidant activity.

• Journal of Aquaculture
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• v.3 no.2
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• pp.155-165
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• 1990

The albinic phenomenon of flat-fish (Paralichthys olivaceus) was investigated by measuring protein content, tyrosinase activity, amino acid composition, and contents of vitamin A and C. These materials in the flat-fish feed-stuff were also tested. The amount of skin protein was higher than that of muscle in normal flat-fish. Catechol and L-dopa oxidase activity did not differ between normal and albinic flat-fish. The free amino acid of skin in normal flat-fish was 7.5 times that in albinic one. Sulfur-containing amino acid in normal flat-fish was also 6.3 times that in albinic ones. Vitamin A was not detected in both of flat-fish. The content of vitamin C in normal flat-fish was 7.8 times that in albinic one. The contents of protein, sulfur-containing amino acid and vitamin C in micro-encapsulated feed (one commercial feed in Japan) were the highest among the feed-stuff used in this experiment. The melanin formation of flat-fish skin was affected by substrates such as aromatic amino acid and cofactor such as sulfur amino acid.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.248.2-248.2
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• 2002

This study reports depigmenting potency of 1,3-selenazol-4-one derivatives. which would be based upon the finding of direct inhibition to mushroom tyrosinase. 1,3-Selenazol-4-one derivatives exhibited inhibitory effect on dopa oxidase activity of mushroom tyrosinase. In this study. inhibitory effects of six kinds of 1,3-selenazol-4-one derivatives (3a, 3c, 3d, 3e, 3g and 3i) on mushroom tyrosinase were investigated. (omitted)

• Biomedical Science Letters
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• v.23 no.2
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• pp.64-72
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• 2017

The formation of brown colonies due to phenol oxidase activity on classic agar media containing natural material extracts of Helianthus annuus or on medium containing L-3,4-dihydroxyphenylalanine has been used to identify Cryptococcus species complex. In this study, various natural materials were used to develop a modified medium and to identify five major serotypes of Cryptococcus species complex. Serotypes A, D, and A/D were pigmented on medium using Perilla frutescens var. japonica Hara (PerJ agar) after a three-day incubation. Serotypes B and C were pigmented on PerJ agar after four- and five-day incubations, respectively. Growth time and pigmentation of the five serotypes occurred more rapidly on PerJ agar than on the other media. In addition, colony morphology, size, and pigmentation were specific by serotype. In conclusion, PerJ agar should be used in clinic settings to identify Cryptococcus species complex and its serotypes rapidly.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.1
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• pp.70-82
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• 2008

Objective : The purpose of this study is to examine the effects of Baickbujasan(BB) on the skin damage and depigmentation. Method : The inhibition of tyrosinase activity, melanogenesis and cell viability in cultured B16 melanoma cells were measured. In order to test effects of reduction of melanogenesis, B16 F-10 mouse melanoma stem line was employed to extract melanin from cultured cell, where BB was added or not, and was dissolved in alkali for colorimetric analysis. Also, in order to test skin alteration in C57BL/6 after UV irradiation, the animals were grouped into a UV urradiation group and UV irradiation after BB application group. Dopa oxidase tissue staining was excuted to invesitage the change in the distribution of active melanin cell. The distribution of active melanin cell in inner skin of iNOS after damage from UVB irradiation and the manifestation condition of P53 which takes part in natural death of keratinocyte were examined. Result : The results indicate that BB has significant effects on tyrosinase activity, and melanogenesis in vivo test. BB seems to reduce C57BL/6, external dermatological damage, for instance, erythematous papule, eczema, loss of keratinocyte, reduction in pus, and relieves dermatological damages. Conclusion : BB can be applied externally for UV protection and depigmentation.