• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.601-606
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• 2023

The edible sweetener aspartame is formed from the synthesis of asparagine, one of the amino acids, and phenylalanine. It is a protein ingredient that produces sweetness 200 times higher than sucrose, and is used as a diet product because it is a substance that can replace sugar. Although the effects on animals and humans have been well studied, no studies have been conducted on plant metabolism. In this study, the effect of aspartame metabolism was tested using germinated onion, bean sprouts, and Kalanchoe. The three types of plants with germinated roots showed rapid growth in the early stage of treatment with 1mM aspartame, and showed a nutrient supply effect due to the effect of amino acids, which are constituents. However, when treated for 4 weeks, symptoms similar to lateral roots appear in the form of lignification in onions, the effect of quickly withering is seen in bean sprouts, and senescence of roots appears in 12-week-old Kalanchoe. All of them show accelerated aging after the growth phase. This shows that, among the two amino acids, asparagine is related to auxin generation that induces rapid growth, and it is thought to be the result of lignification due to the effect of phenylalanine.

• Analytical Science and Technology
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• v.25 no.3
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• pp.171-177
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• 2012

A determination method of aromatic amino acids such as trytophan (Trp), tyrosine (Tyr), and phenylalanine (Phe) using luminol-$H_2O_2$-Cu(II) system has been presented. In the presence of an aromatic amino acid, the enhanced chemiluminescence (CL) intensity of luminol-$H_2O_2$-Cu(II) system was obtained by forming a complex between Cu(II) and the amino acid. Based on the above phenomenon, a sensitive and fast determination of three aromatic amino acids was performed using the CL method in batch-type detection system. To optimize determination conditions, the kinetic influence of an aromatic amino acid on the luminol-$H_2O_2$-Cu(II) system and the effects of $H_2O_2$ and Cu(II) concentration, pH, and buffers were investigated. Under the optimized conditions, the calibration curve was linear over the range from $1.0{\times}10^{-6}$ to $2.0{\times}10^{-5}\;M$ for Trp, $1.0{\times}10^{-6}$ to $2.0{\times}10^{-5}\;M$ for Try, and $2.0{\times}10^{-6}$ to $2.0{\times}10^{-5}\;M$ for Phe, respectively. In this range, reproducibility (RSD, n = 4) of Trp, Try, and Phe were 3.21%, 2.64%, and 2.48%, respectively. The limit of detection ($3{\sigma}/s$) was calculated to be $6.8{\times}10^{-7}\;M$ for Trp, $5.7{\times}10^{-7}\;M$ for Try, and $9.6{\times}10^{-7}\;M$ for Phe.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.12 no.1
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• pp.14-22
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• 2012

Objectives: This study was performed to review clinical manifestations of hyperphenylalaninemia patients in Korean. Methods: 178 cases of hyperphenyalaninemia were diagnosed at department of pediatrics, Soonchunhyang University Hospital from January, 1983 to August. We reviewed DNA analysis, MR imaging, EEG, radiography of the left hand and wrist, bone densitometry (BMD), IQ test of hyperphenyalaninemia patients. Results: Out of 178 cases, 161 cases were diagnosed classic phenylketonuria and 17 cases were diagnosed BH4 deficiency. 122 cases performed DNA analysis. R243Q (10.3%), Y204C (9.9%), and IVS4-1G>A (8.1%) mutations were predominant. 22 cases underwent MR imaging. Varying degrees of symmetrical high signal intensity were noted on T2-weighted sequences in the periventricular deep white matter of 15 cases. 23 cases were performed EEG. 12 cases (52.3%) showed abnormal pattern. EEG abnormalities showed in 11 cases. On lumbar BMD four of 11 cases (36%) showed reduced bone density of more than 1 S.D. in four of 11 cases, bone age was less than chronological age by at least one year. 18 cases were performed IQ test. Mean IQ scores was $84{\pm}21.6$. Among older than 15 years (9 cases), Mean IQ scores was $72{\pm}21.2$. PTPS deficiency was 14 cases, DHPR deficiency was 2 cases, and GTPCH deficiency was 1 case. Conclusion: We confirmed there were varieties of DNA mutations. And MR imaging and EEG were nonspecific in PKU patients. Older children showed lower IQ score. Low phenylalanine diet prevents brain damage in PKU patient. Not only first few years of life but also lifetime, Keeping low phenylalanine diet is important.

• Korean Journal of Food Science and Technology
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• v.19 no.5
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• pp.456-462
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• 1987

아스파탐(N-${\alpha}-L-aspartyl-L-phenylalanine-methylester)$은 아스파르트산과 메칠 페닐알라닌의 펩티드결합 화합물로서 설당의 $180{\sim}200$배의 감미도를 가지고 있으며 감미의 성상이 비교적 설탕에 유사하고 충치원인균에 의해서 발효가 되지 않으므로 새로운 설탕의 대체품으로서 국내외적으로 그 소비량이 급증하고 있다. 본고에서는 아스파탐의 감미도와 감미성상, 화학적 안정성과 위생적인 안전성에 대해서 살펴보고 각종 식품에서의 이용현황을 조사하였다. 그리고 현재 사용되고 있는 화학적 합성법을 소개하고 아울러 생산수율이나 제조공정상 화학적 합성법보다 유리할 것으로 생각되는 효소적합성 방법에 대한 연구현황 및 가능성에 대해서 개략적으로 서술하였다.

• Journal of Life Science
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• v.19 no.9
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• pp.1226-1231
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• 2009

Enzyme substitution with recombinant phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) is currently being explored for treatment of phenylketonuria (PKU), an autosomal recessive genetic disorder with mutations of the gene encoding phenylalanine-4-hydroxylase (EC 1.14.16.1). However, oral administration of PAL is limited because of proteolytic digestion in the gastrointestinal tract. The aim of this study was to determine the biochemical properties of PAL and delinate the susceptibility of wild-type PAL to pancreatic proteolysis by exploring several mutants, and to develop therapeutic drugs with PAL for PKU. The specific activity of PAL was assayed and its optimal pH, temperature stability, and intestinal protease susceptibility were investigated. Its $V_{max}$ values for phenylalanine and tyrosine were 1.77 and $0.47{\mu}mol$/ min/mg protein, respectively, and its $K_m$ values were $4.77{\times}10^{-4}$ and $4.37{\times}10^{-4}\;M$, respectively. PAL showed an optimal pH at 8.5, corresponding to the average pH range of the small intestine. It showed no loss of activity at $-80^{\circ}C$ for 5 months and possessed 93.4% of its activity under $4^{\circ}C$ for 4 wks. PAL was susceptible to chymotrypsin digestion and, to a lesser extent, to trypsin, elastase, carboxypeptidase A, and B. The trypsin and chymotrypsin cleaving sites were mutated to investigate protection from pancreatic digestion and the specific activities of these mutants were evaluated. The six mutants displayed low specific activities compared to the wild-type, suggesting that the primary trypsin and chymotrypsin cleaving sites may be essential for catalytic reaction. The PAL mutants could therefore be applied as a pretreatment modality without susceptibility to proteolytic attack, however, additional modification for enhancing enzymatic activity is needed to reduce the Phe levels effectively.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.509-518
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• 2012

The objective of this study was to determine the effect of heat shock treatments on the phytochemicals including antioxidants and anticancer materials in kale (Brassica oleracea L. var. acephala) sprouts. In study I, kale sprouts grown under the growing system for four days were soaked at 40, 50, or $60^{\circ}C$ distilled water for 10, 30, or 60 seconds, and in study II, kale sprouts were soaked at $50^{\circ}C$ distilled water for 10, 20, 30, 45, or 60 seconds. After the heat shock treatments, the sprouts were transferred into normal growing conditions and recovered there for two days. Fresh and dry weights, electrolyte leakage, total phenolic concentration, antioxidant capacity, total flavonoid concentration, phenylalanine ammonia-lyase (PAL) activity, and glucosinolates content of the sprouts were measured before and after the heat shock treatments. As a result, there was a significant decrease in the fresh and dry weight of kale sprouts treated with heat shock compared with control at harvest in study I. Especially, heat shock at $60^{\circ}C$ lead to more pronounced growth inhibition compared with heat treatments at 40 and $50^{\circ}C$. Electrolyte leakage by cell collapse was the highest in the sprouts exposed to $60^{\circ}C$ distilled water, which agreed with the growth results. Heat shock at $50^{\circ}C$ significantly induced the accumulation of phenolic compounds. In study II, fresh weight of kale sprouts at $50^{\circ}C$ heat shock showed a significant decrease compared with the control at one and two days after the treatment. However, the decrease was minimal and dry weight of kale sprouts was not significantly different from that in control. In contrast, the heat shock-treated kale sprouts had higher level of total phenolic concentration than control at harvest. Heat shock treatments at $50^{\circ}C$ for 20 seconds or more showed at least 1.5 and 1.2 times higher total phenolic concentration and antioxidants capacity than control, respectively. The change of the total flavonoid concentration was similar with that of antioxidants. PAL activity after 24 hours of heat shock was higher in all the heat shock-treated sprouts than that in control suggesting heat shock may stimulate secondary metabolic pathway in kale sprouts. Seven glucosinolates were identified in kale sprouts and soaking the sprouts with $50^{\circ}C$ water for 20 seconds had a pronounced impact on the accumulation of total glucosinolates as well as two major glucosinolates, progoitrin and sinigrin, at harvest. In conclusion, this study suggests that heat shock using hot water would be a potential strategy to improve nutritional quality of kale sprouts by inducing the accumulation of phytochemicals with antioxidant and anticancer properties.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.135-153
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• 2015

The aromatic amino acids, which are composed of $\small{L}$-phenylalanine, $\small{L}$-tyrosine and $\small{L}$-tryptophan, are general components of protein synthesis as well as precursors for a wide range of secondary metabolites. These aromatic amino acids-derived compounds play important roles as ingredients of diverse phenolics including pigments and cell walls, and hormones like auxin and salicylic acid in plants. Moreover, they also serve as the natural products of alkaloids and glucosinolates, which have a high potential to promote human health and nutrition. The biosynthetic pathways of aromatic amino acids share a chorismate, the common intermediate, which is originated from shikimate pathway. Then, tryptophan is synthesized via anthranilate and the other phenylalanine and tyrosine are synthesized via prephenate, as intermediates. This review reports recent studies about all the enzymatic steps involved in aromatic amino acid biosynthetic pathways and their gene regulation on transcriptional/post-transcriptional levels. Furthermore, results of metabolic engineering are introduced as efforts to improve the production of the aromatic amino acids-derived secondary metabolites in plants.

• Journal of Mushroom
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• v.18 no.1
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• pp.107-114
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• 2020

Fifteen species of wild mushrooms, which are classified as edible, medicinal, poisonous, or unknown types, were analyzed for their free amino acid contents. The average total amino acid content was 1,120.0 mg/kg in the edible type, 1,037.8 mg/kg in the medicinal type, and 1,010.8 mg/kg in the poisonous or unknown type, respectively. The edible type wild mushrooms showed the highest average content of total essential amino acids; conversely, the poisonous or unknown type showed the lowest content. Leucopaxillus giganteus (OK811) showed the highest total amino acid (1,212.4 mg/kg) and essential amino acid (490.2 mg/kg) contents among edible type, while Pycnoporus sanguineus (OK1071) showed the highest total amino acid (1,233.7 mg/kg) and essential amino acid (412.8 mg/kg) contents among the medicinal type. Among the poisonous or unknown type, Hypholoma fasciculare (OK826) showed the highest total amino acid (1,223.4 mg/kg) and essential amino acid (442.8 mg/kg) contents. The amino acid contents of wild mushrooms are fundamental data for the screening of useful genetic resources with nutritionally superior properties.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.104-104
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• 2018

흑구기자와 구기자에는 류신, 메티오닌, 페닐알라닌, 이소류신 등의 아미노산이 많이 함유되어 있고 무기염류, 베타카로틴, 비타민C 등이 다량으로 함유되어 있다. 이러한 생리활성 물질에 의하여 항산화 작용이 매우 큰 것으로 알려져있으며 간 기능보호, 콜레스테롤 제거, 자양강장 등의 효능이 있는 것으로 알려져있다. 특히 흑구기자에는 안토시아닌의 함유량이 매우 많아 수면장애 개선과 항노화, 피부주름억제, 피부재생효과 등이 있는 것으로 알려져있다. 또한 이러한 안토시아닌 색소는 암세포 발생과 전이를 억제하는것으로도 알려져있다. 즉, 구기자와 흑구기자는 혈액순환을 개선 시키고 혈관의 탄력을 증강시키어 심혈관질환을 개선하는 효과가 있다. 따라서 본 실험에서는 중국의 고원지대(해발 2500m 이상)에서 자생하고있는 구기자와 흑구기자의 생리활성 물질을 분석하여 항산화 효과를 검증하고자 하였다. 그 결과 총 폴리페놀 함량은 흑구기자와 구기자에서 비슷한 함유량을 나타내었다. 안토시아닌의 함량은 구기자보다 흑구기자에서 다량으로 함유되어 있다. 항산화 활성은 구기자보다 흑구기자에서 훨씬 더 양호한 결과를 나타내었다.

• Polymer(Korea)
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• v.28 no.4
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• pp.352-359
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• 2004

Membrane technology was used for the optical resolution of the various racemic compounds such as tryptophan, tyrosine and phenylalanine, using enantioselective membranes prepared from sodium alginate (SA) and glutaraldehyde as a membrane material and crosslinking agent, respectively, The chemical structure of the membranes was characterized with FT-IR spectrophotometry and 3D molecular structure modeling study was done to figure out the optical resolution mechanism through the membrane. Effects of degree of crosslinking, feed concentration, operating pressure and different kinds of feed solution on the membrane performances were studied. As results, it was found that with increasing degree of crosslinking and membrane thickness, and decrease in the concentration of the feed solution and smaller size of solutes, the enantinselectivity of the membrane was improved. When the sodium alginate membranes with 80% of swelling index and 79${\mu}{\textrm}{m}$ of thickness were used, 77% of enantiomeric excess was obtained.