• Journal of the Korean Wood Science and Technology
• /
• 제29권2호
• /
• pp.133-139
• /
• 2001

항균 및 항산화활성이 우수한 산벚나무(Prunus Sargentii)심재 에탄올 추출물로부터 6개의 후라보노이드 화합물을 단리하였다. 이들을 기기분석한 결과, dihydroflavonol인 3,3',4',5,7-pentahydroxyflavanone(taxifolin)을 비롯하여flavanone인 5-hydroxy-7-methoxyflavanone(pinostrobin), 4',5,7-trihydroxyflavanone (naringenin), 3',4',5,7-tetrahydroxyflavanone(eriodictyol), 5,7-dihydroxyflavanone(pinocembrin), 그리고 flavanone의 배당체인 verecundin(7-hydroxyflavanone 5-O-${\beta}$-D-glucopyranoside)로 각각 동정되었다.

• Journal of the Korean Wood Science and Technology
• /
• 제31권1호
• /
• pp.1-9
• /
• 2003

항균활성이 우수한 헛개나무 목부 에탄올 조추출물로부터 7종의 화합물을 단리하였으며, 기기분석 결과 flavonoid인 5-hydroxy-7-methoxyflavone를 비롯하여 5,7-dihydroxyflavone (chrysin), 5,7-dihydroxyflavanone (pinocembrin), 3,5,7-trihydroxyflavanone (pinobanksin), 3,4',5,7-tetrahydroxyflavanone (aromadendrin)과 stilbenoid인 3-hydroxy-5-methoxystilbene과 3,5-dihydroxystilbene (pinosylvin)으로 각각 동정되었다. 이들 단리물질에 대한 항균활성을 조사한 결과 stilbenoid인 3-hydroxy-5-methoxystilbene이 공시균주의 생장을 완전히 저해하여 단리물질 중 활성이 가장 높은 것으로 나타났다. 그 다음이 pinocembrin과 pinosylvin으로 Cryphonectria parasitica, Trametes versicolor, Tyromyces palustris 그리고 Trichoderma viride에 대해 높은 균사생장억제율을 나타내어 활성이 우수한 것으로 나타났다. 그러나, flavonoid인 pinobanksin, 5- hydroxy-7-methoxyflavone, chrysin, 그리고 aromadendrin은 항균활성이 낮은 것으로 나타났다. 이상의 결과, 헛개나무 목부 에탄올 조추출물의 높은 항균활성은 3-hydroxy-5-methoxystilbene과 pinocembrin, 그리고 pinosylvin에서 유래된 것으로 사료되었다.

• Bulletin of the Korean Chemical Society
• /
• 제27권3호
• /
• pp.426-428
• /
• 2006

• Natural Product Sciences
• /
• 제28권3호
• /
• pp.143-152
• /
• 2022

In our study, sixteen known phenolic compounds, including quercetin (1), methyl gallate (2), caesalpiniaphenol C (3), 8S,8'S,7'R-(-)-lyoniresinol (4), 7,3',5'-trihydroxyflavanone (5), sappanchalcone (6), sappanone A (7), taxifolin (8), fisetin (9), fustin (10), (+)-catechin (11), brazilin (12), 3,4,5-trimethoxyphenyl β-ᴅ-glucopyranoside (13), 1-(2-methylbutyryl)phloroglucinol-glucopyranoside (14), (+)-epi-catechin (15), and astragalin (16) and one mixture of two conformers of protosappanin B (17/18) were isolated from the stems of Caesalpinia decapetala var. japonica. Their structures were elucidated based on a comparison of their physicochemical and spectral data with those of literature. To the best of our knowledge, this represents the first isolation of compounds 3, 4, 8, 9, and 10 from C. decapetala and compounds 13 and 14 from the Caesalpinia genus. All the isolated compounds were evaluated for their inhibitory effect against the α-glucosidase enzyme. Among them, two flavonols (1 and 9), one chalcone (6), and one homoisoflavanone (7) exhibited an inhibitory effect on α-glucosidase action with an IC₅₀ range value of 5.08-15.01 μM, stronger than that of the positive control (acarbose, IC₅₀ = 152.22 μM). Kinetic analysis revealed that compounds 1 and 9 showed non-competitive α-glucosidase inhibition, while the inhibition type was mixed for compounds 6 and 7.

• Food Science and Biotechnology
• /
• 제16권1호
• /
• pp.116-122
• /
• 2007

Four compounds with antioxidant activity were isolated from the MeOH extract of peanut shells (pod) and identified as 5,7-dihydroxychromone (1), eriodictyol (2), 3',4',7-trihydroxyflavanone (3), and luteolin (4) by electron impact-mass spectrometry (EI-MS) and nuclear magnetic resonance (NMR) analyses. The relationship between antioxidant activity and chemical structure of the isolated compounds with their analogues [(-)-epicatechin, quercetin, taxifolin] was examined by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and using the 2-deoxy-D-ribose degradation system. The order of antioxidant activity on the basis of DPPH radical-scavenging was quercetin = (-)-epicatechin (6.0 molecules) > taxifolin (4,5 molecules) > 4 (luteolin; 4.0 molecules) > 2 (eriodictyol; 2.5 molecules) > 3 (3',4',7-trihydroxy-flavanone; 2.0 molecules) > 1 (5,7-dihydroxychromone; 0.5 molecules). On the other hand, using the 2-deoxy-D-ribose degradation system, the order of antioxidant activity was quercetin > 4 >> (-)-epicatechin ${\geq}\;2\;{\geq}$ taxifolin > 3 > 1. These compounds from peanut shells may provide defensive measures against oxidative stress and insects in the soil.

• Bulletin of the Korean Chemical Society
• /
• 제32권8호
• /
• pp.2695-2699
• /
• 2011

${\beta}$ Ketoacyl acyl carrier protein synthase III (KAS III) initiates fatty acid synthesis in bacteria and is a key target enzyme to overcome the antibiotic resistance problem. In our previous study, we found flavonoid inhibitors of Enterococcus faecalis KAS III and proposed three potent antimicrobial flavonoids against Enterococcus faecalis and Vancomycin-resistant Enterococcus faecalis with MIC values in the range of 128-512 ${\mu}g/mL$ as well as high binding affinities on the order from $10^6$ to $10^7\;M^{-1}$. Using these series of flavonoids, we conducted biological assays as well as docking study to find potent flavonoids inhibitors of Staphylococcus aureus KAS III with specificities against Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus. Here, we propose that naringenin (5,7,4'-trihydroxyflavanone) and eriodictyol (5,7,3',4'-tetrahydroxyflavanone) are potent antimicrobial inhibitors of Staphylococcus aureus KAS III with binding affinity of $3.35{\times}10^5$ and $2.01{\times}10^5\;M^{-1}$, respectively. Since Arg38 in efKAS III is replaced with Met36 in saKAS III, this key difference caused one hydrogen bond missing in saKAS III compared with efKAS III, resulting in slight discrepancy in their binding interactions as well as decrease in binding affinities. 4'-OH and 7-OH of these flavonoids participated in hydrogen bonding interactions with backbone carbonyl of Phe298 and Ser152, respectively. In particular, these flavonoids display potent antimicrobial activities against various MRSA strains in the range of 64 to 128 ${\mu}M$ with good binding affinities.

• Natural Product Sciences
• /
• 제17권3호
• /
• pp.198-201
• /
• 2011

Tyrosinase is one of the important enzymes in the mammalian melanin synthesis. In the process of melanin synthesis, tyrosine is oxidized to DOPA (3,4-dihydroxyphenylalanine), and DOPA is further oxidized to dopaquinone. Tyrosinase is an enzyme catalyzing this oxidation of tyrosine, so chemicals that inhibit the activity of tyrosinase can be used as skin whitening agents. In this study, we isolated five constituents from the 80% MeOH extract of Morus bombycis cortex by bioactivity-guided fractionation. We performed mushroom tyrosinase inhibition assay. As a result, 7,2',4'-trihydroxyflavanone (1), 2',4',2,4,-tetrahydroxychalcone (2), and oxyresveratrol (3) showed the more potent inhibitory effect compared to kojic acid, a well-known skin whitening agent with antityrosinase effect. Moracinoside M (4) and moracin M-3'-O-${\beta}$-D-glucopyranoside (5) also showed the moderate tyrosinase inhibitory activities.

• Journal of the Korean Wood Science and Technology
• /
• 제29권2호
• /
• pp.140-145
• /
• 2001

천연물 유래의 보다 안전하고 활성이 우수한 항균 및 항산화물질을 탐색할 목적으로 산벚나무 심재로부터 분리한 pinostrobin, eriodictyol, naringenin. pinocembrin, taxifolin, verecundin의 항균 및 항산화활성을 검정 하였다. 배지점적법을 이용하여 항진균활성을 조사한 결과, pinocembrin(5,7-dihydroxyflavanone)이 공시균주 모두에 대해 80% 이상의 균사생장억제율을 나타내어 가장 활성이 우수한 것으로 나타났으며 그 다음이 naringenin(4',5,7-trihydroxyflavanone), 그리고 verecundin(7-hydroxyflavanone 5-O-${\beta}$-D-glucopyranoside)은 활성이 없는 것으로 나타났다. 특히, pinocembrin의 경우 현재 천연물로부터 분리되어 실용화되고 있는 항균물질인 히노키치올에 비견될 수 있는 항진균활성을 나타내었다. 한천배지확산법을 이용한 항세균활성 조사에서는 단리물질 모두 생육저지환을 형성하지 않아 활성이 없는 것으로 나타났다. 또한, 항산화활성 검정을 위해 프리라디칼소거능 및 과산화물가를 조사한 결과, taxifolin(3,3',4',5,7-pentahydroxyflavanone)과 eriodictyol(3',4',5,7-tetrahydroxyflavanone)이 천연항산화제인 ${\alpha}$-tocopherol의 2배의 프리라디칼소거능을 나타내었으며, 항산화지수도 천연항산화제보다 높은 것으로 나타나 항산화활성이 우수한 것으로 판단되었다. 이상의 결과 산벚나무 심재 에탄올 추출물의 높은 항균활성은 pinocembrin에, 항산화활성은 taxifolin과 eriodictyol에 기인하는 것으로 사료되었다.