• Journal of Applied Biological Chemistry
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• v.65 no.3
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• pp.195-202
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• 2022

Soybean (Glycine max L.) leaves have been researched as functional food stuff actively, but there is no validation method to control quality of soybean leaves (SL). In this study, we annotated seven kaempferol derivatives to confirm camelliaside A as index metabolite in SL using UHPLC-ESI-TOF-MS. HPLC-UVD validation method of camelliaside A in hot-water extract of SL was established according to validation guideline of functional foods from the Ministry of Food and Safety of Korea. The HPLC-UVD method was validated with reliable parameters for examining specificity, accuracy, precision, limit of detection and quantification and linearity. The established method gave the suitable ranges to qunatitate camelliaside A from the hot-water extract of soybean leaves.

• KSBB Journal
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• v.23 no.2
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• pp.131-134
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• 2008

Tea seed extract, a byproduct of tea processing, contains two kaempferol glycosides, camelliaside A and camelliaside B. Kaempferol was produced by enzymatic hydrolysis of glycosides. Optimum reaction conditions were investigated. $Pectinex^{(R)}100L$ was effective, producing kaempferol in 48 hrs. Optimum temperature and pH were $40^{\circ}C$ and 4, respectively. Ratio of substrate and enzyme affected the yield. Under optimum conditions, 1.6g kaempferol per 1 kg tea seed extract was produced and 80% of kaempferol precipitated. This result shows that kaempferol could be produced mildly and effectively using tea-processing byproduct.

• Applied Chemistry for Engineering
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• v.23 no.4
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• pp.394-398
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• 2012

Astragalin (AS), kaempferol monoglycoside, is classified as a polyphenol, and a minute quantity of AS is known to be present in several plants. Recently, it was reported that AS can be prepared by the partial hydrolysis of camelliaside A (CamA) and camelliaside B (CamB) in the tea seed extract (TSE) in the presence of a commercial enzyme complex such as Mash. In this paper, the effects of reaction temperature, amount of enzyme, and the substrate concentration on the reactivity were investigated. As the reaction temperature or the amount of enzyme increased, the reaction rate to produce AS increased, however, the hydrolysis of AS into KR was also enhanced. As a conclusion, the reaction, when 2 mL of Mash to 1 g of TSE was applied with a substrate concentration of 15% at $50^{\circ}C$, was found to be optimum, based on the reaction rate and the selectivity to AS.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.503-511
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• 2023

The aim of this study was to investigate in vitro antioxidant activities of defatted Camellia japonica L. seeds (DCJS). The DCJS were extracted using ethanol and then fractionated with butanol (BuOH), ethyl acetate (EtOAc), chloroform, and hexane. To evaluate antioxidant activity of extract and fractions from DCJS, we investigated free radical scavenging activities such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺), hydroxyl radical (^•OH), and superoxide anion (O₂^-) radicals. The five extract and fractions of DCJS dose-dependently increased DPPH, ABTS⁺ and O₂^- radical scavenging activities. The BuOH fraction of DCJS showed the highest free radical scavenging activities among other extract and fractions. The contents of total polyphenol and flavonoid in BuOH fraction of DCJS were 23.26 mg GAE/g and 32.39 mg QE/g, respectively. The polyphenol and flavonoids contents of BuOH fraction has highest than other extract and fractions. In addition, BuOH and EtOAc fraction of DCJS contained 102.37 and 165.05 ㎍/g of camelliaside B, respectively. Therefore, DCJS has higher antioxidant activity and may be useful as a natural antioxidant material.