• Korean Journal of Soil Science and Fertilizer
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• v.8 no.4
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• pp.189-194
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• 1975

On a newly reclaimed acidic soil, investigation was made to find out the influence of lime and P application at a largeg uantity on the uptake of Zn by corn and its distribution among the leaves, under afactorial combination with two levels of Zn, lime, and P. The results are summarized as following. 1. The application of lime for neutralization of soil significantly reduced the uptake of Zn by corn. 2. Liberal doses of P (5% of P absorption coefficient of soil; 500ppm) applied before sowing did not influence the uptake of Zn. 3. The concentration of Zn in bottom leaves better reflected the Zn uptake status of corn than the upper leaves. The concentration of Zn in bottom leaves responded clearly to the treatments of lime and Zn, while those of upper leaves tended to be constant unresponding to application of lime and Zn. 4. On the present experimental condition, the yield of corn was increased with the increase of P application. But the concentration of P in plant tissue remained constant under different P levels. 5. Application of lime (calcium hydroxide) on low P plots, depressed the yield of corn significantly. It was speculated that the lime applied at large dose made the applied P less available to corn.

• Journal of Life Science
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• v.29 no.3
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• pp.354-361
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• 2019

The red pepper (Capsicum annuum L.) is one of the most important vegetables in traditional Korean food, containing vitamins A, C, and E, polyphenol, and flavonoids. In addition, red peppers have high anti-oxidant ability and are known to be effective in preventing obesity, diabetes, hypertension, digestive disorders, stress, and aging. In this study, we investigated the effects against obesity and diabetes of both fermented and non-fermented red pepper. C57BL/6N mice with induced obesity from an eight-week 45% high fat diet (HFD) were then fed either an HFD or diets containing 2.5% non-fermented red pepper marc (NRM), 1.25% fermented red pepper marc (FRM), or 2.5% FRM for a further eight weeks. An oral glucose tolerance test was performed seven weeks after dietary intake, and body weight, liver, epididymal fat weight, serum insulin level, and HOMA-IR were measured and a lipid content test performed at eight weeks. The results show that the 2.5% FRM diet reduced body and tissue weight, lipid content, serum insulin levels, and HOMA-IR compared to the 2.5% NRM and HFD diets. These results suggest that fermented red pepper is effective against obesity and diabetes. We will use this information as the basic data for the development of health food materials using red pepper.

• Journal of Life Science
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• v.33 no.2
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• pp.169-175
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• 2023

As a protective defensive mechanism against ultraviolet (UV) light exposure in skin tissue, melanocytes produce the pigment melanin. Tyrosinase plays a key role in melanin production in melanocytes. However, the overproduction of melanin can lead to lesions, such as freckles and dark spots. Thus, it is clinically important to find a modulating molecule to control melanogenesis by regulating tyrosinase expression and/or activity. It is known that catechin, a plant flavonoid, can reduce melano- genesis through the downregulation of tyrosinase expression. Here, we tested whether catechin derivatives isolated from the stem bark of Ulmus parvifolia have an effect on melanin production by regulating tyrosinase in mouse melanoma cells and in vitro mushroom tyrosinase. The catechin derivatives used in this study included C5A, C7A, C7G, and C7X. Treatments using these catechin derivatives reduced melanin production in mouse melanoma B16F10 cells in which melanogenesis was stimulated by α-MSH. Notably, the anti-melanogenic effects of catechin derivatives were similar to those of kojic acid, a well-known anti-melanogenic molecule. Both C5A and C7A directly inhibited the activity of tyrosinase isolated from mushrooms in vitro. Furthermore, our in silico computational simulation showed that these two compounds were expected to bind to the active site of tyrosinase, which is similar to kojic acid. In addition, all four catechin derivatives reduced tyrosinase protein expression. In summary, our results showed that catechin derivatives can reduce melanogenesis by regulating tyrosinase activity or expression. Thus, this study suggests that catechin derivatives isolated from U. parvifolia can be novel modulators of melanin production.