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Suigen, South Korea

Rho H.S.,Amore Pacific | Ahn S.M.,Amore Pacific | Lee B.C.,Morechem Corporation | Kim M.K.,Samkyung Costech Co. | And 3 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2010

The tyrosinase inhibitory activity of ethanolic extract of kenaf (Hibiscus cannabinus L.) leaf was evaluated before and after subjecting it to far-infrared (FIR) irradiation. The main component of the extract was analyzed as kaempferitrin (kaempferol-3,7-O-α-dirhamnoside). Prior to FIR irradiation, no inhibitory activity of the extract was detected in a tyrosinase assay. However, after FIR irradiation for 1 h at 60 °C, significant tyrosinase inhibitory activity (IC 50 = 3500 ppm) was observed in it. In HPLC analysis, derhamnosylation products (kaempferol, afzelin, and α-rhamnoisorobin) were detected. The inhibitory activity may be due to the existence of derhamnosylation products. This study demonstrated that FIR irradiation can be used as a convenient tool for deglycosylation of flavonoid glycoside. © 2010 Elsevier Ltd. All rights reserved. Source


Rho H.S.,Amore Pacific | Ahn S.M.,Amore Pacific | Yoo D.S.,Kangwon National University | Kim M.K.,Samkyung Costech Co. | And 2 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2010

This study was conducted to examine the tyrosinase inhibitory and anti-inflammatory activities of kojic acid derivatives. A series of kojic acid derivatives containing thioether, sulfoxide, and sulfone linkages were synthesized. In the tyrosinase assay, kojyl thioether derivatives containing appropriate lipophilic alkyl chains (pentane, hexane, and cyclohexane) showed potent inhibitory activity. However, sulfoxides and sulfones exhibited decreased activity. Similar experimental results were obtained with inhibitory activities of NO production being induced by LPS. The presence of thioether linkage and appropriated lipophilic acid moiety was critical for the tyrosinase inhibitory and anti-inflammatory activities. © 2010 Elsevier Ltd. All rights reserved. Source


Kim B.,Enprani Co. | Kim J.E.,Enprani Co. | Lee S.M.,Enprani Co. | Lee S.-H.,Yonsei University | And 6 more authors.
Experimental Dermatology | Year: 2011

We synthesized a novel derivative of a well-known skin-lightening compound niacinamide, N-nicotinoyl dopamine (NND). NND did not show inhibitory effects of tyrosinase and melanin synthesis in B16F10 mouse melanoma cells. However, NND retains high antioxidant activity without affecting viability of cells. In a reconstructed skin model, topical applications of 0.05% and 0.1% NND induced skin lightening and decreased melanin production without affecting the viability and morphology of melanocytes and overall tissue histology. Moreover, no evidence for skin irritation or sensitization was observed when 0.1% NND emulsion was applied onto the skin of 52 volunteers. The effect of NND on skin lightening was further revealed by pigmented spot analyses of human clinical trial. Overall, NND treatment may be a useful trial for skin lightening and treating pigmentary disorders. © 2011 John Wiley & Sons A/S. Source


Kim J.-K.,Korea Polytechnic University | Kim M.,Korea Polytechnic University | Cho S.-G.,Konkuk University | Kim M.-K.,Samkyung Costech Co. | And 2 more authors.
Journal of Industrial Microbiology and Biotechnology | Year: 2010

Mulberroside A, a glycosylated stilbene, was isolated and identified from the ethanol extract of the roots of Morus alba. Oxyresveratrol, the aglycone of mulberroside A, was produced by enzymatic hydrolysis of mulberroside A using the commercial enzyme Pectinex®. Mulberroside A and oxyresveratrol showed inhibitory activity against mushroom tyrosinase with an IC50 of 53.6 and 0.49 μM, respectively. The tyrosinase inhibitory activity of oxyresveratrol was thus approximately 110-fold higher than that of mulberroside A. Inhibition kinetics showed mulberroside A to be a competitive inhibitor of mushroom tyrosinase with L-tyrosine and L-DOPA as substrate. Oxyresveratrol showed mixed inhibition and noncompetitive inhibition against L-tyrosine and L-DOPA, respectively, as substrate. The results indicate that the tyrosinase inhibitory activity of mulberroside A was greatly enhanced by the bioconversion process. © Society for Industrial Microbiology 2010. Source


Kim H.,Yonsei University | Kim H.,Enprani Co. | Kim M.,Samkyung Costech Co. | Quan Y.,Kyoto Pharmaceutical University | And 9 more authors.
Skin Research and Technology | Year: 2012

Background: The novel hybrid retinoid, retinyl retinoate, is a synthetic material that was designed to reduce the side effects of retinoic acid and to increase the stability of retinol. The formulation of the retinyl retinoate, however, is required to enhance skin permeation, and thus to increase the anti-wrinkle effect. Aim: To identify the efficacy of retinyl retinoate microsphere using biodegradable polymer as an anti-aging agent of cosmetics in treating females over 30 years old with periorbital wrinkles. Methods: The retinyl retinoate microsphere was prepared using the biodegradable polymer; polylactic acid (PLA). We also conducted two clinical studies with a total of 44 Korean women for 12 weeks. In the first clinical study, 20 patients completed a 12-week trial of cream A [3% PLA-retinyl retinoate (2%) microsphere] applied twice daily to the face. In the second clinical study, 24 patients completed a 12-week trial of cream B (0.06% retinyl retinoate) applied twice daily to the face. Efficacy was based on a global photodamage score, photographs, and image analysis using replicas and Visiometers every 4 weeks. Results: The PLA-retinyl retinoate microsphere was more effective for the permeation of retinyl retinoate than retinyl retinoate in itself. The cream A, which contains 3% PLA-retinyl retinoate (2%) microsphere, showed a statistically significant improvement in facial wrinkles (P<0.05) in 20 volunteers after only 4 weeks of application in a clinical trial test. The visual wrinkle improvement and the maximum roughness improvement rate (R2) for cream A was 6.05%, 8.03% higher than that of cream B which contains 0.06% retinyl retinoate, after 4 weeks. Conclusion: Retinyl retinoate has a potent anti-wrinkle activity, and the PLA-retinyl retinoate microsphere could be a useful cosmeceutical product for anti-aging purposes. © 2011 John Wiley & Sons A/S. Source

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