• 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.

• Archives of Pharmacal Research
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• v.28 no.5
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• pp.518-528
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• 2005

In the present study, the antioxidative and inhibitory activity of Zingiber officinale Rosc. Rhizomes-derived materials (on mushroom tyrosinase) were evaluated. The bioactive co mponents of Z. officinale rhizomes were characterized by spectroscopic analysis as zingerone and dehydrozingerone, which exhibited potent antioxidant and tyrosinase inhibition activities. A series of substituted dehydrozingerones [(E)-4-phenyl-3-buten-2-ones] were prepared in admirable yields by the reaction of appropriate benzaldehydes with acetone and the products were evaluated in terms of variation in the dehydrozingerone structure. The synthetic analogues were examined for their antioxidant and antityrosinase activities to probe the most potent analogue. Compound 26 inhibited Fe$^{2+}$-induced lipid peroxidation in rat brain homogenate with an IC$_{50}$ = 6.3${\pm}$0.4 ${\mu}$M. In the 1,1-diphenyl- 2-picrylhydrazyl (DPPH) radical quencher assay, compounds 2, 7, 17, 26, 28, and 29 showed radical scavenging activity equal to or higher than those of the standard antioxidants, like ${\alpha}$-tocopherol and ascorbic acid. Compound 27 displayed superior inhibition of tyrosinase activity relative to other examined analogues. Compounds 2, 17, and 26 exhibited non-competitive inhibition against oxidation of 3,4- dihydroxyphenylalanine (L-DOPA). From the present study, it was observed that both number and position of hydroxyl groups on aromatic ring and a double bond between C-3 and C-4 played a critical role in exerting the antioxidant and antityrosinase activity.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.4
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• pp.307-314
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• 2013

Purpose: The aim of this study was to evaluate the effect of immobilization of the recombinant human bone morphogenetic protein 2 (rhBMP-2) on anodized titaum implants coated with heparin to enhance the vertical alveolar ridge augmentation in the supraalveolar peri-implant defect region. Materials and methods: 18 pure titanium implants (7.0 mm in length, 3.5 mm in diameter) were manufactured for this study. All implants were anodized and designed insertion reference line marked with laser at the apical 2.5 mm from the fixture platform. Implantation of 6 noncoated anodized implants (Control group), 6 anodized implants physically adsorbed with rhBMP-2 by dip and dry method (BMP group) and 6 anodized implants chemically immobilized 3,4-dihydroxyphenylalanine (DOPA)-heparin/ rhBMP-2 (Hep-BMP group) was performed in the both mandibular of three male adult beagle dogs using split-mouth design. Radiologic examinations were performed immediately after implant placement and 4 and 8 weeks after implant placement. The amount of mesio-distal bone augmentation was evaluated by measuring the vertical distance from the platform to the marginal bone. Statistical analysis was performed using one-way analysis of variance (SPSS version 18.0) and multiple comparison analysis of The Kruskal-Wallis test and the Mann-Whitney U test. Statistical significance was established at the 5% significant level. Results: At the 4 weeks vertical alveolar ridge augmentation of Control group, BMP group and Hep-BMP group is $0.09{\pm}0.22mm$, $1.02{\pm}0.72mm$, and $1.29{\pm}0.51mm$, At the 8 weeks $0.11{\pm}1.26mm$, $1.11{\pm}0.58mm$, $1.59{\pm}0.79mm$ according to radiographic observations. The two experimental groups showed a significantly increasing in vertical bone height compared with the control group (P<.05). However, there is no significant difference between the BMP group and Hep-BMP group (P>.05). Conclusion: The rhBMP-2 coated implants were enhanced the vertical bone growth in the supraalveolar peri-implant defect area. However, there is no significant difference between chemically and physically coating method.

• Journal of Microbiology and Biotechnology
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• v.22 no.2
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• pp.207-214
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• 2012

Laccase- and peroxidase-free tyrosinase has commercial importance in the production of L-3, 4-dihydroxyphenylalanine (L-DOPA), which is mainly used in the treatment of Parkinson's disease. In the present study, isolation of an actinomycetes microbial strain capable of producing only tyrosinase is reported. Among all soil isolates, three individual colonies revealed black color around the colony in the presence of tyrosine. Further screening for laccase and peroxidase activities using syringaldazine denoted that one of the isolates, designated as RSP-T1, is laccase and peroxidase negative and produces only tyrosinase. The microbe was authenticated as Streptomyces antibioticus based on 16S ribotyping. Effective growth of this isolate was noticed with the use of medium (pH 5.5) containing casein acid hydrolysate (10.0 g/l), $K_2HPO_4$ (5.0 g/l), $MgSO_4$ (0.25 g/l), L-tyrosine (1.0 g/l), and agar (15 g/l). The scanning electron micrograph depicted that the microbe is highly branched and filamentous in nature. The enzyme production was positively regulated in the presence of copper sulfate. The impact of different fermentation parameters on tyrosinase production depicted that the maximized enzyme titer values were observed when this isolate was grown at 6.5 pH and at $30^{\circ}C$ temperature under agitated conditions (220 rpm). Among all the studied physiological parameters, agitation played a significant role on tyrosinase production. Upon optimization of the parameters, the yield of tyrosinase was improved more than 100% compared with the initial yield.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.41-41
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• 2023

Red pepper (Capsicum annuum L.) is one of the most consumed vegetable worldwide. In this study, we tried to suggest the possibility of Cheongyang pepper as a functional cosmetic material by identifying the physiological activity, especially antioxidant and whitening effects of Cheongyang pepper through bibliometric analysis and experimental studies. A bibliometric analysis was performed through co-word analysis of 8,892 papers retrieved from SCOPUS. 4 research fields were obtained by cluster mapping from VOSviewer software, among which we noted the antioxidant activity of extracts from Capsicum annum L.. Phenol as a useful ingredient of Cheongyang pepper was analyzed using HPLC (high-performance liquid chromatography). Antioxidant and whitening effects were evaluated by measuring DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, hydrogen peroxide scavenging activity, and tyrosinase inhibitory activity. Cheongyang pepper extract showed contents of 0.106 ± 0.01 and 0.105 ± 0.02 mg/g, respectively, in the order of gallic acid and protocatechuic acid. The extract exhibited 56.95% DPPH scavenging activity and 43.97% hydrogen peroxide scavenging activity at a concentration of 1,000 ㎍/ml. In addition, 1,000 ㎍/ml of the extract inhibited tyrosinase activity by 52.44% and 42.61%, respectively in a whitening efficacy test using L-tyrosine and L-DOPA (L-3,4- dihydroxyphenylalanine) as substrates. These results suggest that Cheongyang pepper extract and its active ingredients have antioxidant and whitening effects, and the possibility of future development as a whitening functional cosmetic material.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.29-33
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• 2004

Low molecular weight silk fibroin (LMSF), which was prepared by hydrolysis of silk fibroin using high-temperature and high-pressure method, was found to inhibit the oxidation of L-3,4,-dihydroxyphenylalanine (L-DOPA) catalyzed by mushroom tyrosinase (EC 1.14.18.1). LMSF contained mostly free amino acids such as L-glycine, L-alanine, and L-serine and oligopeptides, mainly glycine-alanine dimer. As a result of analyzing the inhibition kinetics from Lineweaver-Burk plots, L-glycine and glycine-alanine dimer showed noncompetitive behavior while uncompetitive behavior was observed in L-alanine, and L-serine. When weight percent concentration of ${ID_50}$ was compared, L-glycine was most effective on the inhibition and LMSF was also good enough for the inhibition effect of tyrosinase activity. LMSF showed a mixed-type inhibition and the inhibitory mechanism of LMSF might be caused by free amino acids and oligopeptides. As a result of spectroscopic observation with time, initial rate of increase of DOPAchrome decreased remarkably and the time to reach maximum absorbance increased as an increase of the concentration of L-glycine, meaning that L-glycine made itself mainly responsible for the formation of chelate with ${Cu^2+}$ in tyrosinase. However, in case of L-alanine, L-serine, and especially glycine-alanine dimmer, the production of DOPAchrome after an arrival at maximum absorbance decreased, indicating the production of adducts through the reaction with DOPAquinone.

• Journal of Life Science
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• v.19 no.1
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• pp.75-80
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• 2009

Melanogenesis is a physiological process that results in the synthesis of melanin pigments. Tyrosinase is a key enzyme for melanin biosynthesis, and hyperpigmentation disorders are associated with abnormal accumulation of melanin pigments, which can be improved by treatment with depigmenting agents. Among the possible melanin-reducing compounds, tyrosinase inhibitors are most promising for preventing and treating pigmentation disorder and are used as skin-whitening agents in the cosmetic industry. In the present study, the effects of fucoidan on melanogenesis and tyrosinase activity of B16F10 melanoma cells were investigated. Melanin synthesis and tyrosinase activity in B16F10 melanoma cells were decreased in a dose-dependent manner by fucoidan. Melanin production and tyrosinase activity in B16F10 melanoma cells stimulated by a-melanocyte stimulating hormone (a-MSH) were inhibited by fucoidan with a dose-dependent manner compared to control. Fucoidan inhibited tyrosinase activity of B16F10 melanoma cells with a dose-dependent manner as assessed by 3,4-dihydroxyphenylalanine (DOPA) staining. In conclusion, these findings indicate that fucoidan, which inhibit melanin synthesis and tyrosinase activity, is an effective skin-whitening agent.

• Journal of Life Science
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• v.29 no.6
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• pp.688-696
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• 2019

This study investigated changes in triglyceride and cholesterol synthesis and tyrosinase activity induced by ice plant (Mesembryanthemum crystallinum L.) extract, which cannot be stored for long periods of time due to its high moisture content when it was fermented to improve its storage stability. The accumulation of triglyceride and cholesterol in HepG2 cells inhibited the accumulation with a relatively large magnitude in n-butanol and aqueous fractions that generally have high polarity, however, changes in inhibition potency due to the fermentation were not significant. As for the effect to inhibit tyrosinase activity, when L-tyrosine was used as a substrate, the inhibitory activity was the highest for the aqueous fraction at $60.58{\pm}4.03%$ and $63.35{\pm}4.35%$, before and after fermentation, respectively, which amounted to 72% of that of the positive control group (arbutin, $100{\mu}g/ml$). In addition, when L-3,4-dihydroxyphenylalanine (L-DOPA) was used as a substrate, the inhibitory activity was also found the highest for the aqueous fraction at $56.85{\pm}1.57%$ and $59.38{\pm}1.74%$, before and after fermentation, respectively, which amounted to at least 88% of that in the positive control (kojic acid, $100{\mu}g/ml$). Overall, the activity of the fermented ice plant extract was similar or a little higher compared to that of the one without fermentation, indicating that fermentation can be a good approach to improve the storage stability of the ice plant.