• Journal of the Korean Chemical Society
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• v.40 no.9
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• pp.623-629
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• 1996

In order to identify antibiotic substances in the extract of a lichen, Umbilicaria vellea, the extract was chromatographed and two compounds were isolated. Compound I which showed antifungal and antibacterial activities, melted around 129∼132$^{\circ}C$ and showed UV absorption at 217, 265 and 300 nm. It showed a molecular ion at m/z 196. Its molecular formular was confirmed to be $C_{10}H_{12}O_4$ from elemental analysis. From its IR and NMR data it was identified to be ethyl 2,4-dihydroxy-6-methyl benzoate. Compound II melted around 58∼59$^{\circ}C$ and showed UV absorption at 212, 276 and 282 nm. It showed a molecular ion at m/z 124 and molecular formular was confirmed to be $C_7H_8O_2.$ From the analysis of its IR and NMR spectra it was identified to be 5-methyl-1,3-benzenediol.

• Applied Biological Chemistry
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• v.32 no.4
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• pp.401-407
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• 1989

A series of novel 1,3-substituted-5-chloropyrazole-4-carboxylic acid oxime esters was synthesized. Their chemical strictures were elucidated on $^1H,\;^{13}C-NMR$ and IR spectra, Fifteen such compounds were screened for their antifungal activity against R. solani, P. oryzae, B. cinerea, P. graminearum, P. capsici and G. cingulata. The results showed that pyrazole-oxime esters with electron withdrawing groups(III, XIII, XIV) had better biological activities than these with electron releasing groups.

• Journal of Microbiology and Biotechnology
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• v.16 no.7
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• pp.1111-1119
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• 2006

Beauvericins and enniatins are cyclohexadepsipeptides exhibiting various biological activities on animal systems, including humans. Fusarium oxysporum FB1501 (KFCC 11363P) that produces four different cyclohexadepsipeptides was isolated from soil in Korea and the structures of the four cyclohexadepsipeptides elucidated by HPLC, MS, IR, and NMR analyses. The molecular weights for compounds 1,2,3, and 4 were determined to be 654.5, 784.5, 668.6, and 682.5, respectively, on the basis of ESI-MS measurements. The IR spectra for all the compounds exhibited absorptions for ester $(1,733-1,743\;cm^{-1})$ and amide $(1,649-1,655\;cm^{-1})$ bonds that were very similar to those for beauvericin and enniatins with ester and amide absorptions. The results of the NMR analysis $(^{1}H,\;^{13}C,\;135-DEPT,\;COSY,\;HMQC,\;and\;HMBC;\;in\;COCl_{3})$ revealed that compounds 1,3, and 4 consisted of $_{L}-N-methyl\;valine$ (N-MeVal), $_{D}-{\alpha}-hydroxyisovaleic\;acid$ (Hiv), and 2-hydroxy-3-methylpentanoic acid (Hmp) residues (compound 1: three N-MeVal residues, two Hiv residues, and one Hmp residue; compound 3: three N-MeVal residues, one Hiv, and two Hmp residues; compound 4: three N-MeVal residues and three Hmp residues). Therefore, the compounds were identified as enniatin H (compound 1), enniatin I (compound 3), and enniatin MK1688 (compound 4). Compound 2 was analyzed as beauvericin according to 1D and 2D NMR analyses. This study is the first report related to the co-production of beauvericin with other unusual enniatins, such as enniatin H, enniatin I, and enniatin MK1688, by Fusarium oxysporum.

• Bulletin of the Korean Chemical Society
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• v.8 no.2
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• pp.96-101
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• 1987

2-Ethoxy-6-methoxy-5-cyano-3,4-dihydro-2H-pyran (1_a$), 2-n-butoxy-6-methoxy-5-cyano-3,4-dihydro-2H-pyr an (1b), 2-isobutoxy-6-methoxy-5-cyano-3,4-dihydro-2H-py ran ($1_c$), and 2-ethoxy-6-methoxy-3-methyl-5-cyano-3,4-dihydro -2H-pyran ($1_d$) were prepared by (4 + 2) cycloaddition reaction of methyl $\alpha$-cyanoacrylate with the corresponding alkyl vinyl ethers. Compounds $1_{a-d}$ were ring-open polymerized by cationic catalyst to obtain alternating head-to-head (H-H) copolymers. For comparison, head-to-tail (H-T) copolymer $3_a$ was also prepared by free radical copolymerization of the corresponding monomers. The H-H copolymer exhibited minor differences in its $1_H% NMR and IR spectra, but in the $^{13}C$ NMR spectra significant differences were observed between the H-H and H-T copolymers. Glass transition temperature ($T_g$) of H-H copolymer was higher than that of the H-T copolymer, but thermal decomposition temperature of the H-H copolymer was lower than that of the H-T copolymer. Compounds $1_a$, $a_b$, and $1_c$, copolymerized well with styrene by cationic catalyst, but compound 1d failed to copolymerize with styrene. All of the H-H and H-T copolymers were soluble in common solvents and the inherent viscosities were in the range 0.2-0.4 dl/g.

• Journal of the Korean Chemical Society
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• v.47 no.1
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• pp.38-42
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• 2003

For the purpose of developing new agrochemical fungicides, compound 2 possessing 1,3-thiazole scaffold as well as urea moiety in the structure was designed through molecular modification of lead compound, 2-imino-1,3-thiazoline based on isosterism. The reaction of N-methylthiouea 5 and bromoacetonitrile in ethanol gave 2,4-diimino-1,3-thiazole 4 regioselectively, which was treated with phenyl isocyanates to give the corresponding 7 which is tautomer of 2. The structural assignment of 7 was confirmed by various spectra($^1H$ NMR, $^{13}C$ NMR, FT-IR, HRMS), and X-ray crystallographic data. Compound 8 which is a structural isomer of 7 was formed through thermodynamically unstable intermediate 2,4-diimino-1,3-thiazole 6.

• Microbiology and Biotechnology Letters
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• v.28 no.4
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• pp.233-238
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• 2000

To develop biodegradable and safe flocculant, Achromobacter sp. HY-66 were isolated from soil. The purified flocculant was composed of fructose and glucose in an approximate molar ratio of 1:24. Molecular weight was approximately 9$\times$105 dalton by Sepharose CL-4B gel filtration chromatography. Elemental analysis revealed that the contents of carbon, hydrogen and oxygen were 37.72%, 5.37% and 56.89%, respectively. The presence of O-H stretching, C-H streching, carboxy ester and C-H bending were confirmed by IR absorption spectrum analysis. We suggest that a bioflocculant produced from Achromobacter sp. YJ-66 is new and different from other bioflocculants.

• Preventive Nutrition and Food Science
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• v.13 no.3
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• pp.241-244
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• 2008

Methanol extracts were prepared from Z. schinifolium leaf and successively fractionated with chloroform, butanol, and water. The butanol fraction exhibited the highest antioxidative activities. Therefore the butanol fraction was purified and a chemical structure was identified by $^1H-^{13}C-NMR$ spectra, and FT-IR. The isolated antioxidative substance was identified as quercitrin.

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.412-417
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• 2011

A series of homobinuclear complexes of the type [$M_2L(NO_3)_n(H_2O)_m$] where M=$UO_2$(VI), ZrO(IV), Th(IV); L=3-benzylidine-imino-5-p-sulphonamido phenyl azo-2-thiohyatoin(bispt), 3-furfurylidine-imino-5-p-sulphonamido phenyl azo-2-thiohydantoin(fispt),3-pyridyl-2'-methylene-imino-5-p-sulphonamido phenyl azo-2-thiohydantoin(pmispt) and 3-thienyl-2'-methylene-imino-5-p-sulphoanamido phenyl azo-2-thiohydantoin(tmispt); n=8 for Th(IV) and 4 for others, m=4 for bispt and 3 for others have been synthesized and characterized on the basis of elemental analysis, thermal analysis, molar conductance, magnetic moment and spectroscopic data (IR, electronic and $^1H$-NMR). In the light of this information, the ligands can be visualized as tetradentate co-ordinating through azomethine nitrogen, carbonyl oxygen to one metal centre where as azo nitrogen and thioimido nitrogen to the other metal centre yielding homo binuclear complexes of the above composition. The fungi toxicity of the ligands & their zirconyl complexes against some fungal pathogen has been studied.

• Bulletin of the Korean Chemical Society
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• v.7 no.5
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• pp.334-337
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• 1986

The preparation of the metal-metal bonded complex $Cp_2ZrClFeCp(CO)_2$ has been achieved by the reaction of $Cp_2ZrCl_2$ and strong nucleophile $NaFeCp(CO)_2$. The more soluble metal-metal bonded complexes $Cp_2ZrRFeCp(CO)_2(R=CH_3,\;n-C_8H_{17}$) have also been prepared through the reaction of Cp$_{2}$ZrRCl and NaCpFe(CO)$_{2}$. The complexes were characterized by IR, Raman, $^{1}$H NMR and Mass spectra. The complete absorption (100-3800 cm$^{-1}$) spectra for the three metal-metal bonded molecules are reported and the bands of each vibration were assigned.

• YAKHAK HOEJI
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• v.37 no.2
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• pp.119-123
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• 1993

A spectrophotomertic method is proposed for the determination of antihistamines. The method is based on solvent extraction of the ion pair formed between antihistamines and colored picric acid into chloroform. The binding state of antihistamines-picric acid complexes were presumed by IR and $^{1}$H-NMR spectra as intermolecular hydrogen bonding. This method was applicable to the determination of antihistamines in the pharamaceutical preparations.