• Natural Product Sciences
• /
• 제10권5호
• /
• pp.244-247
• /
• 2004

The inhibitory effects of the leaves of Eucalyptus darylmpleana (Myrtaceae) on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was examined. The scavenging effect of the ethyl acetate fraction of Eucalyptus darylmpleana leaves on DPPH radical was stronger than the other fractions, and further purified by silica gel and Sephadex LH-20 column chromatography. 3,4-Dihydroxybenzoic acid, gallic acid, quercetin, quercetin $3-O-{\alpha}-_L-rhamnoside$, quercetin $3-O-{\beta}-_D-glucoside$ and quercetin 3-O-rutinoside were isolated and elucidated by spectroscopic data. Among these components, gallic acid and quercetin $3-O-{\alpha}-_L-rhamnoside$ exhibited potent scavenging activities on DPPH radical with $IC_{50}$ values of 6.02 and $5.54\;{\mu}M$, respectively.

• 전기화학회지
• /
• 제7권2호
• /
• pp.83-88
• /
• 2004

[ $DeniLite^{TM}$ ] laccase immobilized Pt electrode was used for amperometric detection of some catechol derivatives and o-aminophenol (OAP) derivative by means of substrate recycling. In case of catechol derivatives, the obtained sensitivities are 85, 79 and $57 nA/{\mu}M$ with linear ranges of $0.6\~30,\;0.6\~30\;and\; 1\~25 {\mu}M$ and detection limits (S/N=3) of 0.2, 0.2 and $0.3{\mu}M$ for 3,4-dihydroxycinnaminic acid (3,4-DHCA), 3,4-dihydroxybenzoic acid (3,4-DHBA) and 3,4-dihydroxyphenylacetic acid (3,4-DHPAA), respectively. In case of OAP derivative, the obtained sensitivity is $237 nA/{\mu}M$ with linear range of $0.2\~15{\mu}M$ and detection limit of 70 nM for 2-amino-4-chlorophenol (2-A-4-CP). The response time $(t_{90\%})$ is about 2 seconds for each substrate and the long-term stability is around 40-50days for catechol derivatives and 30 days for 2-A-4-CP with retaining $80\%$ of initial activity. The optimal pHs of the sensor for these substrates are in the range of 4.5-5.0, which indicates that stability of the enzymatically oxidized product plays a very important role in substrate recycling. The different sensitivity of the sensor for each substrate can be explained by the electronic effect of the sugstituent on the enzymatically oxidized form.

• 생약학회지
• /
• 제47권1호
• /
• pp.1-6
• /
• 2016

Phytochemical investigation of the twigs of Corylopsis coreana afforded 10 phenolic compounds, bergenin (1), 6'-O-galloylbergenin (2), 3'-O-galloylbergenin (3), (-)-catechin (4), (-)-epicatechin (5), (-)-epicatechin-3-O-galloyl ester (6), 4-methoxy-3,-5-dihydroxybenzoic acid (7), gallic acid (8), 2,4,6-trimethoxyphenol-1-O-${\beta}-\small{D}$-glucopyranoside (9), and 2,4,6-trimethoxyphenol-1-O-${\beta}-\small{D}$-(6-O-galloyl)-glucopyranoside (10). Their structures were characterized by spectroscopic data and identified by comparing these data with those in the literatures. The compounds 3, 9 and 10 were isolated for the first time from this source. All the isolates (1-10) were tested for their cytotoxic activity against A549, SK-OV-3, SK-MEL-2, and HCT15 cell lines in vitro using the SRB bioassay. The compounds 5, 7 and 8 exhibited selective cytotoxic activity against SK-MEL-2 cell line.

• Genomics & Informatics
• /
• 제13권1호
• /
• pp.2-6
• /
• 2015

Pathogenic bacteria survive in iron-limited host environments by using several iron acquisition mechanisms. Acinetobacter baumannii, causing serious infections in compromised patients, produces an iron-chelating molecule, called acinetobactin, which is composed of equimolar quantities of 2,3-dihydroxybenzoic acid (DHBA), L-threonine, and N-hydroxyhistamine, to compete with host cells for iron. Genes that are involved in the production and transport of acinetobactin are clustered within the genome of A. baumannii. A recent study showed that entA, located outside of the acinetobactin gene cluster, plays important roles in the biosynthesis of the acinetobactin precursor DHBA and in bacterial pathogenesis. Therefore, understanding the genes that are associated with the biosynthesis and transport of acinetobactin in the bacterial genome is required. This review is intended to provide a general overview of the genes in the genome of A. baumannii that are required for acinetobactin biosynthesis and transport.

• 공업화학
• /
• 제18권6호
• /
• pp.625-629
• /
• 2007

최근 피부친화성, 흡수력, 나노 입자의 제조 등에 우수한 특성을 지닌 불포화 레시친에 대한 관심이 높아지고 있다. 이에 따라 불포화레시친의 산화안정성을 높이고, 변질되기 쉽고 독성을 지닌 합성화합물을 대체하는 천연물을 개발하고자 하였다. 결과, 하늘타리(T. kirilowii Maximowicz)의 열매와 뿌리의 성분분석을 한 결과 항산화 성분으로는 갈릭산, 카페인산, 3,5-디하이드록시벤조익산, 플라보논이 검출되었다. 총 폴리페놀 함량은 열매추출물(53.5 mg/g)보다 뿌리추출물(133.85mg/g)에서 높게 나타났고 프리라디칼 제거 및 지질산패 억제효과 또한 뿌리 추출물이 우수하였으며 뿌리 추출물은 폴리페놀 함량이 100 ppm 이상일 때 대조군으로 사용한 BHT보다 약 20.1%, 19.2% 높게 나타났다. 또한 하늘타리 추출물은 1250ppm 이하에서 95% 이상의 높은 세포 생존율을 나타내어 안전성이 우수하였다. 리포좀의 안정성에 대한 효과는 열매보다 뿌리추출물이 우수하였으며 뿌리추출물은 대조군인 BHT에 비해 항산화 효과 15.1%, 제타전위 13.9% 높았으며, 입자크기는 9.3% 낮아 기존의 합성 원료보다 우수하였다

• 한국식품과학회지
• /
• 제43권5호
• /
• pp.558-563
• /
• 2011

복분자 와인은 복분자 열매를 발효 숙성시켜 제조한 것으로, 소비자에게 널리 음용되고 있으나 그 원재료인 복분자 열매에 대한 연구에 비해 복분자 와인에 존재하는 성분들에 대한 체계적인 연구는 거의 전무한 실정이다. 최근 우리는 복분자주에 함유되어 있는 화합물들의 분자 수준에서의 연구를 통하여 4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 4-(2-hydroxyethyl)-phenol, pyrocatechol, ethyl gallate 등의 5종의 저분자 페놀성 화합물을 단리 구조해석하여 보고한 바 있다. 그 연속된 연구로써 본 논문에서는 복분자주에 존재하는 성분들에 대한 추가적인 분리 및 구조해석을 행하였다. 제조된 복분자 와인(11 L, 복분자 열매 15.7 kg)을 용매분획하여 얻어진 EtOAc층(56.2 g)의 일부(20 g)를 silica gel column chromatography와 ODS-HPLC로 정제하여 5종의 화합물을 단리하였다. 이 화합물들을 대상으로 MS 및 NMR 등의 기기분석을 행한 결과, ethyl succinate(1, 13.1 mg), vanillic acid(2, 2.6 mg), ethyl 3,4-dihydroxybenzoate(3, 13. 1 mg), furan-2-ol(4, 1.3 mg), 그리고 4-(4-hydroxyphenyl) butan-2(S)-ol(5, 1.1 mg)로 동정하였다. 이 화합물들 대부분은 발효식품에서 향기성분으로 동정된 바 있으며, 화합물 2는 복분자 열매에 존재함이 이미 보고되어 있으나, 화합물 1과 3-5는 복분자 열매 및 복분자와인으로부터 처음으로 동정되었다.