• Korean Journal of Pharmacognosy
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• v.6 no.2
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• pp.93-99
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• 1975

Polyphenol substances involved in the browning of Malus asiatica $N_{AKAI }$ ('Hong-ok') were examined. It was found that chlorogenic acid was the principal substance. The estimation of polyphenol oxidase activity in Malus asiatica revealed that its browning reaction was caused by enzymatic oxidation of chlorogenic acid.

• Korean Journal of Pharmacognosy
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• v.27 no.4
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• pp.328-335
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• 1996

Effects of hydrogen peroxide$(H_2O_2)$ on polyphenol oxidase (PPO) in Perillae Folium were investigated. The inactivation of this enzyme was dependent on $H_2O_2$ concentration. and the initial lag period was not shown. Preincubation of Perillae Folium PPO with $H_2O_2$ in the absence of a substrate resulted in rapid loss of enzymatic activity. The inactivation of PPO by $H_2O_2$ dependents temperature and pH. OH radical scavengers such as mannitol and sodium formate did not protect the enzyme against inactivation by $H_2O_2$. Substrate analogue such as phenylalanine protected the enzyme against inactivation by $H_2O_2$. and copper chelator such as sodium azide also protected the enzyme.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.94-94
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• 2018

집속초음파 추줄법(Innovative Extraction by Focused Ultrasound, INEFU)은 기존의 추출법에 비교하여 식물세포벽으로부터 기능성 성분을 낮은 온도에서 높은 추출 효율을 얻기 위한 추출공정으로 적용하기 위하여 연구되고 있다. 본 연구에서는 깔라몬딘오렌지(깔라만시, Citrus Madurensis, Citrofortunella microcarpa)에서 Vitamin C와 Polyphenol의 기능성 성분 추출을 위해 INEFU를 적용하여 추출 효율에 미치는 요인을 평가하였다. 추출 변수의 최적화를 위해 추출 온도 및 추출 시간을 요인으로 하여 순차적인 최적화를 진행하였다. 동일한 추출조건에서 저온추출(CEM)과 INEFU를 비교하였을 때 INEFU에서 Vitamin C는 고순도로 26배 증가하여 추출되는 것을 확인하였다. 또한 Polyphenol는 저온추출(CEM)에서는 polyphenol이 극소량 추출되었으나, INEFU에서는 Feruric acid가 10.3배 증가하여 추출되는 것으로 확인하였다. 본 연구를 통해 INEFU가 기존의 추출 공정에 비해 기능성 성분 생산에 보다 효과적임을 확인하였다.

• Korean Journal of Pharmacognosy
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• v.31 no.2
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• pp.240-244
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• 2000

Antimutagenicity profiles of the enzymatic browning reaction products(EBRP) were investigated. The rec-assay with Bacillus subtilis strains $H17(rec^+)$ and $M45(rec^-)$ was carried out using their spores. The biological activities were evaluated for seven different enzymatic browning reaction products, which resulted from the reactions of seven polyphenols with polyphenol oxidase isolated from Ginkgo biloba leaves. In the spore $rec^-$ assay, most of the polyphenolic compounds tested were positive, whereas their enzymatic browning reaction products were tested negative. The mutagenicity of enzymic browning mixtures of the polyphenols and the enzymes obtained from Ginkgo biloba leaves showed negative results in the mutagenicity test using Bacillus subtilis strains $H17(rec^+)$ and $M45(rec^-)$. In the case where polyphenol oxidase inhibitors were added in the enzymatic reaction mixtures with polyphenols, the polyphenols showed mutagenic effect in the spore $rec^-$ assay. This suggests that the activity of polyphenol oxidase is decreased.

• YAKHAK HOEJI
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• v.43 no.6
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• pp.709-715
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• 1999

Polyphenol oxidase (PPO) activity in 200×g (cell wall), 4,000×g (plastid), 100,000×g (mitochondrial) and soluble fractions of the perilla leaves was monitored in the upper, middle and lower sections of the plant. In the course of plant growth, PPO activities in plastid and mitochondrial fractions were decreased, while those in cell wall fraction were maintained. During growing process, specific activities and PPO activities of each fraction were decreased, while total phenol content were decreased in middle (middle) and then increased in later stage (lower). Cell wall, plastid, mitochondrial (pellet) and soluble fraction had slightly different pH optima and substrate specificities. Isoenzyme patterns were identical in two bands for PPO activity in different subcellular fractions. Their molecular weights were 37KD and 48KD respectively.

• IMMUNE NETWORK
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• v.4 no.4
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• pp.250-254
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• 2004

Background: It is necessary for human beings to uptake vitamin C through diet or supplements. It is also well-known that vitamin C plays an important role in the prevention of scurvy, enhancement of collagen synthesis and anti-tumor immune response. In addition, there are several recent reports regarding the effective role of vitamin C on the regulation of allergic responses, such as atopic dermatitis and asthma. However, the effective therapeutic and preventive measures using vitamin C are not established yet, since vitamin C is seriously unstable in aqueous solution. Therefore, we have investigated the best way to maintain the stability of vitamin C. Methods: After we making a mixture of polyphenol (0.001, 0.01, 0.1%) and vitamin C (1 mM), the mixtures were placed at room temperature both with/without light protection. And then the concentration of ascorbic acid was measured with HPLC. To analyze the in vivo effect of vitamin C on the regulation of skin allergic reaction, polyphenol (0.1%)-vitamin C (1 mM) mixture was applied to the skin and the production of histamine from mast cell was analyzed by Evans blue dye staining. Results: We have found that the polyphenol has preventive power of oxidation of vitamin C. In addition, the production of histamine was suppressed by the polyphenol (0.1%)-vitamin C (1 mM) mixture. Conclusion: We have reached the conclusion that our study suggests the research guideline for the therapy of atopic dermatitis through vitamin C.

• Applied Biological Chemistry
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• v.31 no.4
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• pp.331-338
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• 1988

Acetone powder was prepared from raw arrowroots and the polyphenol oxidases of crude enzyme prepared from acetone powder were identified 5 isoenzymes by staining with catechol containing 0.05% phenylene diamine. The crude enzyme was passed through the columns of ion exchangers and gel permeation to fractionate the polyphenol oxidases. The main fraction of polyphenol oxidase appeared to be purified by 94-fold, with the activity yield of 45.4%, and its molecular weight was determined as 38,500 by poly acrylamide gel electrophoresis. The optimal pH and temperature for the enzyme activity were pH 7.5 and $50^{\circ}C$, respectively. The purified enzyme showed a high affinity for catechol and pyrogallol. The Michaelis constant for catechol was calculated to be 16.67mM according to the Lineweaver-Burk method. The enzyme activity was strongly inhibited by L-ascorbic acid, sodium bisulfite, EDTA and KCN, and totally inhibited, by $Fe^{3+}$ at a concentration of 1mM. However the enzyme was activated by $Zn^{2+}$ approximately 1.7 times at the same concentration.

• 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.16 no.2
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• pp.110-117
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• 1987

Polyphenol oxidase in Prunus salicina(Red) was extracted, some properties and its partially purification were investigated as follows; Polyphenol oxidase was purified about 15 folds after ammonium sulfate saturation and about 64 folds after Sephadex G-100 column chromatography. Polyphenol oxidase showed optimum pH for activity at 6.5 and optimum temperature at at $35^{\circ}C$ and high affinity to catechol in o-diphenol compounds. Thermal stability were about 85% and 75% of initial polyphenol oxidase activity remained after heating at $50^{\circ}C$ for 5 minutes and 30 minutes respectively. The Michaelis constant of the enzyme was 2.58mM. L-cysteine, glutathione, ascorbic acid and potassium cyanide appeared to be most effective inhibitors. EDTA showed a slight inhibition.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.693-697
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• 2016

In this study, the electron donating ability(EDA) and total polyphenol content of herbal wine were examined. The herbal wine was obtained from extract concentration to evaluate its functional properties. The herbal wine were screened for their potential antioxidant activities using test such as electron donating ability(EDA) and total polyphenol content. The electron donating ability(EDA) were $21.81{\pm}0.56$ in herbal wine 15% and $40.45{\pm}1.60$ in herbal wine 35%. As the extract concentration was increased the electron donating ability(EDA) were significantly increased(p<0.05). The total polyphenol contents were measures $113.89{\pm}1.79{\mu}g\;GAE/m{\ell}$ in herbal wine 15%, $274.24{\pm}0.71{\mu}g\;GAE/m{\ell}$ in herbal wine 35%. As the extract concentration was increased the total polyphenol contents were significantly increased(p<0.05). Also, the total polyphenol contents were measures $61.75{\mu}g\;GAE/m{\ell}$ in herbal wine, the higher.