• 약학회지
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• 제47권5호
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• pp.300-306
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• 2003

Rhizoma of Smilax china has been used as anti-inflammatory and analgesic, antiedemic agent in Korean folk medicine. In order to investigate the efficacy of anti-oxidative activity, the activity-guided fractionation and the isolation were performed. Each fractions ($H_2O$ fraction, 20％, 40％, 60％, 100％ MeOH fractions and CHCl$_3$ fraction) was examined antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging potential. It was revealed that 40％, 20％ MeOH fractions and $H_2O$ fractions have significant anti-oxidative activity. From 40％ and 20％ MeOH fractions two flavonoid glycosides and one procyanidin were isolated and elucidated apigenin-7-Ο-$\alpha$-L-rhamnopyranosyl(1\longrightarrow2)-$\beta$-D-glucopyranoside, apigenin-7-Ο-$\alpha$-L-rhamnopyranosyl(1\longrightarrow6)-$\beta$-D-glucopyranoside and catechin(4$\alpha$\longrightarrow6)epicatechin through their physicochemical data and IR, FAB-MS, $^{13}$ C-NMR, and $^1$H-NMR analysis with authentics, respectively. The isolated compounds were examined by DPPH method. Apigenin-7-Ο-$\alpha$-L-rhamnopyranosyl(1\longrightarrow2)-$\beta$-D-glucopyranoside and catechin (4$\alpha$\longrightarrow6) epicatechin showed powerful radical scavenging activities on DPPH radical among three compounds.

• 한국약용작물학회지
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• 제8권4호
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• pp.373-377
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• 2000

밤나무(Castanea crenat)의 지상부를 대상으로 DPPH free radical 소거법을 이용하여 2종의 항산화 활성물질을 분리하였다. 분리된 활성물질은 NMR과 mass 분석에 의하여 quercitrin, isoquercitrin으로 밝혀졌다. 두 화합물의 DPPH free radical 소거법에 의한 항산화 활성 $(RC_{50}\;:\;12{\mu}g)$은 BHA $(14\;{\mu}g)$와 ${\alpha}-tocopherol\;(12{\mu}g)$과 비슷하였다.

• 미생물학회지
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• 제50권4호
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• pp.381-383
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• 2014

미생물 기원의 ${\alpha}$-glucosidase 저해제를 탐색하는 과정에서 토양에서 분리한 균주인 Bacillus sp. SKU31-1 배양액에서 강력한 저해제 compound K을 일련의 크로마토그래피 방법에 의해 분리 정제하였고 $^1H$ NMR, $^{13}C$ NMR, $^1H-^1H$ COSY spectra 분석과 문헌조사를 통해 5-amino-1-hydroxymethyl-1,2,3,4-cyclohexanetetrol로 동정되었다. Compound K의 ${\alpha}$-glucosidase 저해 활성은 $IC_{50}$값이 maltose 기질에서는 $1.9{\mu}M$이고, sucrose 기질 사용시 4.9 mM이었다. Lineweaver Burk plot에 의해 $K_i$값이 0.15 mM 로 강력한 경쟁적 저해제 임이 밝혀졌다.

• Natural Product Sciences
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• 제22권1호
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• pp.64-69
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• 2016

A method for simultaneously identifying antioxidative compounds was developed using time-based LC-MS coupled with DPPH assay regardless of the time consuming process. The methanolic extract of Polygonum aviculare (Polygonaceae) showed significant DPPH radical scavenging activity. Time-based DPPH assay for simultaneous identification of active compounds from the extracts of P. aviculare was used. Major peaks of ethyl acetate fraction of P. aviculare showed high DPPH radical scavenging activity. A simple phenolic compound (1) and six flavonoids (2-7) were isolated from the ethyl acetate fraction of P. aviculare by silica gel and sephadex LH-20 column chromatography. The structures of seven compounds were determined to be protocatechuic acid (1), catechin (2), myricitrin (3), epicatechin-3-O-gallate (4), avicularin (5), quercitrin (6), and juglanin (7) based on the analysis of the $^1H$-NMR, $^{13}C$-NMR and ESI-MS data. All compounds exhibited significant antioxidant activity on DPPH assay and active compounds were well correlated with predicted one.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.150.1-150.1
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• 2011

Structure-II hydrate has been highlighted due to its higher gas storage capacity and favorable thermodynamic conditions. In this study, we introduce a new structure-II hydrate former, tert-butyl hydroperoxide (TBHP) and confirm the structural characteristics through High-Resolution Powder Diffraction (HRPD), $^{13}C$ solide-state NMR and Ramanspectroscopy. Here,we also investigated the thermodynamic stability of binary(TBHP+gaseous) clathrate hydrates. The experimental data were generated using an isochoric pressure-search method. The dissociation data for (TBHP +gaseous) clathrate hydrates are compared with the other hydrocarbon hydrate and pure gaseous hydrate.

• Natural Product Sciences
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• 제22권3호
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• pp.216-219
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• 2016

The microbial transformation of anthranilic acid (1) by the marine-mudflat-derived fungus Thielavia sp. produced an antibacterial polycyclic quinazoline alkaloid, thielaviazoline (2). The stereostructure of the metabolite was assigned based on detailed spectroscopic data analyses including comparison of the NMR ($^1H$ and $^{13}C$) data with those of reported compound (2). Compound 2 displayed in vitro antimicrobial activity against methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA), with minimum inhibitory concentrations (MICs) of 6.25 and $12.5{\mu}g/mL$, respectively. Compound 2 also showed potent radical-scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) with an $IC_{50}$ of $11{\mu}M$, which was more active than the positive control, L-ascorbic acid ($IC_{50}$, $20.0{\mu}M$).

• Bulletin of the Korean Chemical Society
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• 제20권12호
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• pp.1469-1474
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• 1999

New platinum(II) complexes with asymmetrically substituted chiral diamine ligands A₂PtX₂, (A₂ = NH₂CH(CH₃)CH₂NH($c-C_5H_9)$ (apcpa), NH₂CH(CH₃)CH₂NH($c-C_6H_11)$ (apcha); X₂ = 2Cl, isopropylidenmalonate (IPM), 1,1'-cyclobutandicarboxylate (CBDCA)) have been synthesized and characterized by means of elemental analyses, infrared and NMR spectroscopies, and X-ray crystallography. The crystal structures of (S-apcha)Pt[CBDCA] ·3H₂O (orthorhombic, P2₁2₁2(No. 18), a = 6.926(3), b = 15.243(3), c = 19.319(4)Å, V = 2039.5(10) ų, Z = 4, R = 0.072) and (S-apcha)Pt[IPM] ·2.5 H₂O (monoclinic, P2/C(No. 13), a = 9.882(1), b =18.502(1), c = 22.056(1)Å, V = 4032.8(5)ų, Z = 8, R=0.093) exhibit that the platinum atoms achieve a typical square planar arrangement with two nitrogen atoms in cis position and with the chiral center retained. The spectroscopic data disclose that these platinum complexes are stable and their molecular structures are retained in aqueous solution. Among these platinum complexes, the asymmetric diamine-Pt(II) complexes with chloride leaving group exhibit high in vivo activity comparable to cisplatin against leukemia L1210 cell line.

• 대한화장품학회지
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• 제43권1호
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• pp.53-60
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• 2017

본 연구에서는 수박 덩굴(잎 및 줄기) 추출물 및 용매 분획물의 미백 및 항염 활성을 검색하고 유효성분을 분리하여 화학구조를 규명하였다. 수박 덩굴 에탄올 추출물 및 용매 분획물의 멜라닌 생성 억제활성을 측정한 결과, 헥산 및 에틸아세테이트 분획물에서 우수한 멜라닌 생성 억제 효과가 있음을 확인하였다. 또한 항염 활성측정 결과, 헥산 및 에틸아세테이트 분획물에서 활성이 나타남을 확인하였다. 헥산 및 에틸아세테이트 분획물에서 유효성분을 찾고자 칼럼 크로마토그라피를 실시하여 3개의 화합물을 분리하였으며 $^1H$ 및 $^{13}C$ NMR 데이터 분석 및 문헌치 비교를 통하여 화학구조를 동정하였다; ${\alpha}-linolenic$ acid (1), sigmast-7-en-O-${\beta}$-D-glucopyranoside (2), 1-feruloyl-${\beta}$-D-glucopyranoside (3). 분리된 화합물에 대한 미백 활성 실험 결과, 화합물 1과 3에서 멜라닌 생성 및 세포 내 티로시나제 효소의 활성을 감소시키고 있음을 확인하였다. 또한 항염 활성 실험 결과 화합물 1과 3이 nitric oxide (NO) 및 전염증성 사이토카인($TNF-{\alpha}$, IL-6)의 생성을 억제시킴을 확인하였다. 이상의 연구 결과를 바탕으로 수박 덩굴 추출물을 이용한 천연 미백 및 항염 소재로의 개발이 가능할 것이라 사료된다.

• The Plant Pathology Journal
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• 제29권1호
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• pp.77-86
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• 2013

Anthracnose development by Colletotrichum musae was observed to be significantly less in the fruits of the banana cultivar 'Embul' (Mysore, AAB) infected with Phyllosticta musarum than in fruits without such infections. Anthracnose disease originates from quiescent C. musae infections in the immature fruit. P. musarum incites minute, scattered spots, referred to as freckles, in the superficial tissues of immature banana peel which do not expand during maturation or ripening. P. musarum does not appear to have a direct suppressive effect on C. musae as conidia of C. musae germinate on both freckled and non-freckled fruit forming quiescent infections. Our investigations have shown that P. musarum infection induced several defence responses in fruit including the accumulation of five phytoalexins, upregulation of chitinase and ${\beta}$-1,3-glucanase, phenylalanine ammonia lyase (PAL) activity and cell wall lignification. $^1H$ and $^{13}C$ NMR spectral data of one purified phytoalexin compared closely with 4'-hydroxyanigorufone. Some of the P. musarum-induced defences that retained during ripening, restrict C. musae development at the ripe stage. This paper examines the potential of P. musarum-induced defences, in the control of anthracnose, the most destructive postharvest disease in banana.

• 대한화학회지
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• 제40권11호
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• pp.692-698
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• 1996

해양천연물 Discokiolide B의 옥사졸 골격인 discokiic acid 1을 합성하였다. 2[2'-(4-Phenyl-3-butenyl)]-1, 3-oxazole-4-carboxaldehyde(4a)와 methyl propionate의 리튬 enolate와의 알돌반응으로부터 discokiic acid methyl ester를 합성하였다. 중요한 반응중간체인 2[2'-(4-Phenyl-3-butenyl)]-1, 3-oxazole-4-carboxaldehyde(4a)는 디아조 말론알데히드와 니트릴을 로듐촉매하에서 반응시켜 얻었다. Discokiic acid의 오른쪽 측쇄 부분인 3-hydroxy-2-methyl 프로판산 부분의 상대적인 입체화학을$^1H$와 $^{13}C$ 핵자기공명 데이터에 근거하여 결정하였다.