• Mycobiology
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• 제49권4호
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• pp.434-437
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• 2021

In our ongoing search for new secondary metabolites from fungi, a basidiomycete fungus Irpex consors was selected for mycochemical investigation, and three new zwitterionic alkaloids (1-3) and five known compounds (4-8) were isolated from the culture broth (16 l) of I. consors. The culture filtrate was fractionated by a series of column chromatography including Diaion HP-20, silica gel, and Sephadex LH-20, Sep-Pak C₁₈ cartridge, medium pressure liquid chromatography (MPLC), and high pressure liquid chromatography (HPLC) to yield eight compounds (1-8). The structures of the isolated compounds were elucidated by the interpretation of nuclear magnetic resonance (NMR) spectra and high-resolution mass spectrometry (HR-MS). Their antioxidant and antibacterial activities were examined. The zwitterionic structures of three new sesquiterpene alkaloids (1-3) were determined together with five known compounds identified as stereumamide E (4), stereumamide G (5), stereumamide H (6), stereumamide D (7), and sterostrein H (8). This is the first report of the zwitterionic alkaloids in the culture broth of I. consors. Three new zwitterionic alkaloids were named as consoramides A-C (1-3).

• Bulletin of the Korean Chemical Society
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• 제25권11호
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• pp.1661-1666
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• 2004

The reaction of titanium tetraisopropoxide with 2 equiv of N,N-diethyl acetoacetamide affords Ti($O^iPr)_2(CH_3COCHCONEt_2)_2$ (1) as colorless crystals in 80% yield. Compound 1 is characterized by spectroscopic (Mass and $^1H/^{13}C$ NMR) and microanalytical data. Molecular structure of 1 has been determined by a single crystal X-ray diffraction study, which reveals that it is a monomeric, cis-diisopropoxide and contains a six coordinate Ti(IV) atom with a cis($CONEt_2$), trans($COCH_3$) configuration (1a) in a distorted octahedral environment. Variable-temperature $^1H$ NMR spectra of 1 indicate that it exists as an equilibrium mixture of cis, trans (1a) and cis, cis (1b) isomers in a 0.57 : 0.43 ratio at -20$^{\circ}C$ in toluene-$d_8$ solution. Thermal properties of 1 as a MOCVD precursor for titanium dioxide films have been evaluated by thermal gravimetric analysis and vapor pressure measurement. Thin films of pure anatase titanium dioxide (after annealing above 500$^{\circ}C$ under oxygen) have been grown on Si(100) with precursor 1 in the substrate temperature range of 350- 500$^{\circ}$ using a bubbler-based MOCVD method.

• 한국환경과학회지
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• 제20권6호
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• pp.687-700
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• 2011

A new $N_3-O_2$ pentadentate ligand, H-BHPT, was synthesized. Hydrochloric acid salts of Br-BHPT, Cl-BHPT, $CH_3O$-BHPT and $CH_3$-BHPT, having Br-, Cl-, $CH_{3-}$ and $CH_3O-$ substituents at the para position of the phenol hydroxyl group of H-BHPT were synthesized. Hydrochloric acid salts of 3OH-BHPT and 4OH-BHPT, having different position of the phenol hydroxyl group of H-BHPT were also synthesized. The synthesis of each ligand was confirmed by C. H. N. atomic analysis and $^1H$ NMR, $^{13}C$ NMR, UV-visible, and mass spectra. The calculated proton dissociation constants ($log{K_n}^H$) of the phenol hydroxyl group and secondary amine group of the synthesized $N_3-O_2$ ligands showed five steps of the proton dissociations. The order of the overall proton dissociation constants ($log{\beta}_p$) of the ligands was Br-BHPT < Cl-BHPT < H-BHPT < $CH_3O$-BHPT < $CH_3$-BHPT. The order agreed with that of Hammett substituent constants (${\delta}_p$). However, dissociation steps of 3OH-BHPT were four and that of 4OH-BHPT was three. The calculated stability constants ($logK_{ML}$) between the ligands and transition metal ions agreed with the order of $log{\beta}_p$ values of the ligands. The order of the stability constants between the transition metal ions with the synthesized ligands was Co(II) < Ni(II) < Cu(II) > Zn(II) > Cd(II) > Pb(II). The order agreed well with that of the Iriving-Williams.

• 한국환경과학회지
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• 제21권4호
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• pp.421-435
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• 2012

Novel $N_2O_2$ tetradentate ligands, H-3BPD and H-2BPD were synthesized. Hydrochloric acid salts of Br-3BPD, Cl-3BPD, Br-2BPD and Cl-2BPD having Br and Cl substituents at the $para$ position of the phenol hydroxyl group, were synthesized. The ligands were characterized by C. H. N atomic analysis, $^1H$ NMR, $^{13}C$ NMR, UV-visible, and mass spectra. The proton dissociation constants ($logK_n{^H}$) of the phenol hydroxyl group and secondary amine of the synthesized $N_2O_2$ ligands were shown by four step wise values. The orders of the calculated overall proton dissociation constants ($log{\beta}_p$) were Br-3BPD < Cl-3BPD < H-3BPD in case of 3BPD and Br-2BPD < Cl-2BPD < H-2BPD in case of 2BPD respectively. The order agreed well with that of $para$ Hammett substituent constants(${\delta}_p$). The stability constants($logK_{ML}$) of the complexes between the synthesized ligands and transition metal(II) ions agreed with the order of $log{\beta}_p$ of the ligands. The order of the $logK_{ML}$ value of the each transition metal (II) ion was Co(II) < Ni(II) < Cu(II) > Zn(II) > Cd(II) > Pb(II), which agreed well with that of Iriving-Williams series.

• 한국환경과학회지
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• 제19권7호
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• pp.849-860
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• 2010

A new $N_3O_2$ pentadentate ligand, N,N'-Bis(2-hydroxybenzyl)-ethylenetriamine(H-BHET 3HCl) was synthesized. The hydrochloric acid salts of Br-BHET 3HCl, Cl-BHET 3HCl, $CH_3O$-BHET 3HCl and $CH_3$-BHET 3HCl containing Br-, Cl-, H-, $CH_3O-$ and $CH_3-$ groups at the para-site of the phenol group of the H-BHEP were synthesized. The structures of the ligands were confirmed by C. H. N. atomic analysis and $^1H$ NMR, $^{13}C$ NMR, UV-visible and mass spectra. The calculated stepwise protonation constants(${\logK_n}^H$) of the synthesized $N_3O_2$ ligands showed six steps of the proton dissociation. The orders of the overall protonation constants($\log{\beta}_p$) of the ligands were Br-BHET < Cl-BHET < H-BHET < $CH_3O$-BHET < $CH_3$-BHET. The orders agreed well with that of para Hammett substituent constants(${\delta}_p$). The calculated stability constants($\logK_{ML}$) between the ligands and heavy metal ions (Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II)) agreed well with the order of the overall proton dissociation constants of the ligands but they showed a reverse order in para Hammestt substituent constants(${\delta}_p$). The order of the stability constants between the heavy metal ions with the synthesized ligands were Co(II) < Ni(II) < Cu(II) > Zn(II) > Cd(II) > Pb(II).

• 대한화학회지
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• 제55권1호
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• pp.19-27
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• 2011

2-(Benzothiazol-2-yl)-N'-(2,5-dihydroxybenzylidene)acetohydrazide 에대한새로운일련의 Mn(II), Ni(II), Co(II), Cu(II) 및 Zn(II) 착물을 합성하여 그 특성을 원소분석, IR, UV-vis, $^1H$-NMR, 질량분석, ESR, 자기수자율 및 몰 전기전도도 측정에 의하여 조사하였다. 이들 착물의 기하구조가 사각평면 또는 팔면체임을 분광학적 데이터 및 자기적 측정으로부터 알았다. 이 리간드와 해당착물의 세균에(Aspergillus nigar 및 Fusarium oxysporium) 대한생물학적활성을 조사하였다. 그 결과, 금속착물들은 리간드 및 금속이온 모두에 비해 더 큰 활성을 나타내었다.

• 생약학회지
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• 제46권2호
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• pp.105-108
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• 2015

To establish the anti-diabetic(α-glucosidase inhibitory) activity of D. lotus leaf extract, isolate and identify the constituents responsible for the activity. The methanolic extract of leaves was partitioned between water, n-butanol and ethyl acetate. Bio-assay guided fractionation, based on inhibition of ;${\alpha}$-glucosidase, allowed isolation and identification of the active components. Liquid chromatography/mass spectrometry(LC/MS), ¹ H-NMR and ¹³ C-NMR spectra analyses demonstrated that the active compound was myricetin-3-O-;${\alpha}$-L-rhamnoside(1). Compound 1 demonstrated a strong inhibition on the α-glucosidase, in vitro and ;${\alpha}$-glucosidase inhibitory value was calculated as 98.08%, when that of a reference drug, acarbose was estimated as 83.03%. The present study indicates compound 1 could be considered as an ;${\alpha}$-glucosidase inhibitor and developed as an important antidiabetes agent for type II diabetes therapy.

• Applied Biological Chemistry
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• 제43권4호
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• pp.298-302
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• 2000

식용버섯 유래의 저분자 대사산물을 탐색하던 중 충남 계룡산 일대에서 채집한 능이버섯(Sarcodon aspratus)으로부터 7종의 화합물을 분리하였다. 능이버섯을 메탄올에 추출한 후 용매분획하여 그 중 화합물이 많이 함유된 chloroform층과 ethyl acetate층에 대하여 각각 silica gel 및 Sephadex LH-20 column chromatography를 수행하였다. 주요 대사산물을 함유하고 있는 분획물을 TLC 및 분취용 HPLC를 사용하여 최종적으로 정제하여 7종의 화합물을 분리하였다. 이들 화합물은 $^1H\;NMR$, mass 분석 및 문헌 data와 비교하여 각각 4-hydroxybenzoic acid methyl ester, 4-hydroxybenzaldehyde, cyclo(Ala-Pro), adenosine, nicotinamide, BL V, linoleic acid으로 동정되었다.

• 한국약용작물학회지
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• 제13권4호
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• pp.182-185
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• 2005

사람들의 생명연장과 각종 만성질환, 악성종양 등의 증가에 따른 우수한 항생제의 계속적인 개발로 많은 생명을 구할 수 있게 되었지만 반면 항생제를 지나치게 사용하여 이에 많은 부작용이 생기고 내성균도 많아지면서 중증감염이 증가되어 여러 가지의 새로운 문제점에 직면하게 되었다. 안전성이 있는 새로운 항균물질의 개발 목적으로 예비 검색 결과 선택된 독활을 추출하여 컬럼 크로마토그래피를 반복 수행한 결과 2종의 항균 효과를 보여주는 화합물을 분리하였다 이들 화합물은 물리 화학적 성질 및 분광학적 분석을 통하여 화합물 1은 mp가 $166{\sim}167^{\circ}C$인 백색침상, $C_{20}H_{30}O_2$의 분자식을 갖는 (-)-pimara-8(14), 15-dien-19-oic acid 즉, continentalic acld으로 동정하였으며, 화합물 2는 mp가 $164{\sim}165^{\circ}C$인 백색침상, $C_{29}H_{48}O$의 분자식을 갖는 $(24E)-stigmasta-5,\;22-dien-3{\beta}-ol$, 즉 stigmasterol으로 동정하였으며 항균효과를 측정한 결과 두 화합물 모두 유의성 있는 결과를 나타내었으며, 이 중 화합물 1인 continentalic acid이 더욱 우수한 활성을 나타내었다. 특히 그람 양성균인 S. aureus에서 MIC가 $7.8\;{\mu}g/ml$, E. faecalis에서는 MIC가 $12.5\;{\mu}g/ml$에서 비교적 강한 억제 효과를 보였으며, 화합물 2에서는 S. aureus에서 MIC가 $7.8\;{\mu}g/ml$, S. epidemidis에서는 MIC가 $12.5\;{\mu}g/ml$에서 억제 효과를 보여 주었으나 그람 음성균에서 $100\;{\mu}g/ml$ 이상으로 항균활성이 측정되지 않았다. 따라서 화합물 1과 화합물 2는 그람 양성균에 대한 새로운 항균제로 개발에 유용한 화합물이 될 것으로 기대된다.

• 대한화학회지
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• 제56권6호
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• pp.679-691
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• 2012

New series of metal complexes of Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and Pt(II) with 4-(p-chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide (HCPTS) have been synthesized and characterized by elemental analyses, magnetic moment, spectra (IR, UV-Vis, $^1H$ NMR, mass and ESR) and thermal studies. The IR data suggest different coordination modes for HCPTS which behaves as a monobasic bidentate with all metal ions except Cu(II) and Zn(II) which acts as a monobasic tridentate. Based on the electronic and magnetic studies, Co(II), Cu(II), Pd(II) and Pt(II) complexes have square - planner, Ni(II) has mixed stereochemistry (tetrahedral + square planar), while Zn(II) is tetrahedral. Molar conductance in DMF solution indicates the non-ionic nature of the complexes. The ESR spectra of solid copper(II) complex show $g_{\parallel}$ (2.2221) > $g_{\perp}$ (2.0899) > 2.0023 indicating square-planar structure and the presence of the unpaired electron in the $d_x2_{-y}2$ orbital with significant covalent bond character. The thermal stability and degradation kinetics of the ligand and its metal complexes were studied by TGA and DTA and the kinetic parameters were calculated using Coats-Redfern and Horowitz-Metzger methods. The complexes have more antibacterial activity against some bacteria than the free ligand. However, the ligand has high anticancer activities against HCT116 (human colon carcinoma cell line) and HEPG2 (human liver hepatocellular carcinoma cell line) compared with its complexes.