Dae‐Ok Kim
경희대학교 의과대학·의학전문대학원 · 의학
김대옥 교수의 연구실은 주로 식물성 천연물에서 유래한 폴리페놀 화합물의 항산화 능력을 정량화하고, 이를 바탕으로 건강 기능성 식품 및 생체적 보호 효과를 규명하는 데 초점을 맞추고 있습니다. 특히, 비타민 C 당량 항산화능력(VCEAC)을 활용한 정량적 평가와 HPLC, 스펙트로포스메트릭 기법을 통해 다양한 과일(사과, 플럼, sour 체리 등)의 폴리페놀 성분과 항산화 활성을 체계적으로 분석하고 있습니다. 또한, 항산화 물질이 신경세포에 미치는 보호 작용에 대한 기전 연구도 병행하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
To express the antioxidant capacity of plant foods in a more familiar and easily understood manner (equivalent to vitamin C mg/100 g), two stable radical species, ABTS(*)(-) and DPPH(*), commonly used for antioxidant activity measurements, were employed independently to evaluate their efficacies using apple polyphenolic extracts and seven polyphenolic standards including synthetic Trolox. Their antioxidant activities were expressed as vitamin C equivalent antioxidant capacity (VCEAC) in mg/100 g
Total phenolics, total flavonoids, and antioxidant capacity of 11 cultivars of fresh plums were determined using spectrophotometric methods. Identification and quantification of individual polyphenolics were performed using reversed-phase high-performance liquid chromatography equipped with a diode array detector. The total phenolic contents of various cultivars widely varied from 125.0 to 372.6 mg/100 g expressed as gallic acid equivalents. The level of total flavonoids in fresh plums ranged be
Antioxidant capacity for a wide range of natural or synthetic polyphenolics was comprehensively evaluated by vitamin C equivalent antioxidant capacity (VCEAC) assay using free blue/green ABTS radicals. The polyphenolics tested are grouped into the following categories: vitamins (beta-carotene, alpha-tocopherol, vitamin A, and vitamin C), phenolic acids (benzoic acid, phenylacetic acid, cinnamic acid, and their derivatives), flavonoids (anthocyanidin, flavanol, chalcone, flavanone, flavone, flavo
The identification of phenolics from various cultivars of fresh sweet and sour cherries and their protective effects on neuronal cells were comparatively evaluated in this study. Phenolics in cherries of four sweet and four sour cultivars were extracted and analyzed for total phenolics, total anthocyanins, and their antineurodegenerative activities. Total phenolics in sweet and sour cherries per 100 g ranged from 92.1 to 146.8 and from 146.1 to 312.4 mg gallic acid equivalents, respectively. Tot
We present a new approach to introduce hierarchical porosity along with electrical conductivity into three-dimensional metal–organic frameworks.
The introduction of hierarchical porosity into metal‐organic frameworks (MOFs) has been of considerable interest in gas separation and heterogeneous catalysis due to the efficient mass transfer kinetics through meso/macropores. Here, a facile, scalable approach is reported for the preparation of carbon nitride (CN) foams as structural templates with micrometer‐sized pores and high nitrogen content of 25.6 wt% by the fast carbonization of low‐cost melamine foam. The nitrogen functionalities of CN
ABSTRACT: Four cultivars of sour cherries (Balaton, Karneol, Kroeker and Northstar), 2 cultivars of plums (BY 8158.50 and Methley), and 1 red raspberry cv. Prelude were analyzed for total phenolics, antioxidant capacity, and total anthocyanins before and after jam production to evaluate their changes after thermal processing. Fruits had total phenolics ranging from 245.7 to 398.5 mg gallic acid equivalent (GAE)/100 g. Antioxidant capacity of fruits ranged from 354.8 to 692.3 mg/100 g, expressed
ABSTRACT: Ten fresh cabbage genotypes ( Brassica oleraceavar capitata ) representing fresh‐market, processing, and storage types were evaluated for total phenols, antioxidant capacity, and flavonoids at the 3‐wk juvenile stage, at which time plants are uniform in size when grown under identical soil and environmental conditions. The genotypes studied, ‘Bobcat,’‘Fresco,’‘Little Rock,’‘Marvelon,’‘Rinda,’‘Ramada,’‘Transam,’‘Genesee,’‘Huron,’ and ‘Octoking,’ showed significant variations in concentr
Intercalation phenomena of gas molecules in the interlayer of graphene oxide have been investigated using CO2, CH4, H2, and N2 gases. Intercalation of gas molecules is highly affected by the affinity between the hydrophilic surface of GO and target molecules. Among tested gases, CO2 can only be intercalated. Furthermore, the swelling of interlayer changed the intercalation phenomena. Amounts of intercalated gases are significantly enhanced, and all the gases can be intercalated by retarded dynam
(1) Background: Extensive research has focused on flavan-3-ols, but information about the bioactivities of green tea flavonols is limited. (2) Methods: In this study, we investigated the antioxidative, anti-inflammatory, and anticancer effects of flavonol glycosides and aglycones from green tea using in vitro cell models. The fractions rich in flavonol glycoside (FLG) and flavonol aglycone (FLA) were obtained from green tea extract after treatment with tannase and cellulase, respectively. (3) Re
Understanding of gas hydrates, for example, phase equilibria, in reservoir sediments is one of the important issues in the fields of energy production and CO2 sequestration via CH4 hydrate exploitation and CO2 hydrate formation. The composition of water in clay can change their physical properties, which influences the state in which gas hydrates exist in clays. We investigated gas hydrates in crystalline-swelled Na-montmorillonite (CS-mon) having water content of <27 wt % and maintaining crysta