• Bulletin of the Korean Chemical Society
• /
• v.32 no.11
• /
• pp.3887-3892
• /
• 2011

An efficient synthesis of 1,5-Benzothiazepines via Michael addition of corresponding (E)-1-(2-hydroxyphenyl)-3-(4-(phenylthio)phenyl)prop-2-en-1-one is described under ultrasound irradiation. A series of novel 2-((E)-2,3-dihydro-2-(4-(phenylthio)phenyl)benzo[b][1,4]thiazepin-4-yl)phenol derivatives was confirmed on the basis of $^1H$ NMR, Mass, IR spectral data and Elemental analysis. The synthesized compounds were evaluated for their antimicrobial activities. Most of the compounds were found to be comparable potent than the reference standard drugs. Utilization of ultrasound irradiation, simple reaction conditions, isolation, and purification makes this manipulation very interesting from an economic and environmental perspective.

• Journal of the Korean Chemical Society
• /
• v.63 no.6
• /
• pp.435-439
• /
• 2019

An efficient one pot multicomponent synthesis of pyrimidinone derivatives of Biginelli type is described. 4-amino-6-aryl-pyrimidine-5-carbonitrile molecules were synthesized efficiently via three-component Biginelli-type condensation of aldehyde, malononitrile, and semicarbazone as urea substituent in the presence of a catalytic amount of PEG-400 as green medium under microwave irradiation. The reactions proceeded efficiently in the presence of microwave radiation to afford the desired products in good to excellent yields. Products have been confirmed by IR, and NMR spectral analysis. All the molecules were tested for their antimicrobial activity against E. coli, S. aureus, P. aeruginosa and C. tropicalis. Some of the compounds have shown moderate to good inhibition efficiency against both gram-positive and gram-negative bacteria. The potent activity was observed against the fungal species with minimum inhibition concentration 12.5 ㎍/mL.

• Natural Product Sciences
• /
• v.2 no.2
• /
• pp.96-101
• /
• 1996

A new natural product, 3,4,8-trihydroxybenzopyranopyran-6,9-dione was isolated from the aqueous ethanolic gall extract of Tamarix aphylla (Tamaricaceae) along with the known phenolics, monodecarboxyellagic acid and brevifolin carboxylic acid as well. The structures have been established by ESI-MS, $^1H$ and $^{13}C$ NMR spectral analysis. Antiinflammatory, antipyretic and ulcerogenic activities determination for both plant (Tamarix aphylla and Phragmites australis) were carried out on aq. ethanolic of extracts.

• Natural Product Sciences
• /
• v.23 no.2
• /
• pp.119-124
• /
• 2017

The isolation of the MeOH extract from the flower bud of Magnolia biondii Pamp. using various column chromatographies and HPLC led to eleven neoglignan derivatives (1 - 11). Their structures were mainly determined by 1D and 2D NMR spectral data analysis and physiological methods. The isolated compounds (1 - 11) were tested for anti-allergic effects using IL-2 inhibitory assay in Jurkat T cells.

• Microbiology and Biotechnology Letters
• /
• v.22 no.4
• /
• pp.368-372
• /
• 1994

Three more unusual macrolides in addition to concnamycin B were isolated from the mycelium of Streptomyces sp. strain Bal6. These four compounds showed a potent cytotoxity to hunian cancer cell lines, SNU-1 (stomach cancer cell line), SNU-354 (liver cancer cell line), MCF- 7 (breast cancer cell line) and KB-3-1 (oral epidermoid carcinoma cell line). Interestingly, these compounds confered slight differential cytotoxity on RHEK-1, a human epidermal keratinocyte cell line immotalized by AD12-SV40 hybrid virus and RHEK-1/pSV$_{2}$ ras which was resulted from H-ras transfomation of RHEK-1. These compounds were determined to be concanamycin A, conca- namycin E and 0-methyl concanamycin B by NMR and other spectral analysis.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.137.2-138
• /
• 2003

The steam distillate obtained from sawdust of Thujopsis dolabrata var. hondai was fractionated by centrifugal thin-film evaporation. and then the fractions were investigated against antiplatelet activity using washed rabbit platelets in vitro. The biologically active constituent of T. dolabrata sawdust was isolated by silica gel column chromatography and HPLC and characterized as carvacrol by various spectral analysis ($^{1}H$, $^{13}C$-NMR and GC/MS studies). (omitted)

• Journal of the Korean Chemical Society
• /
• v.56 no.4
• /
• pp.459-463
• /
• 2012

8-Formyl-4-Methyl-7-Hydroxy Coumarin Derivatives were synthesized via Penchem condensation followed by Duffs reaction. Treatment of this with N,N-di substituted cyano acetamides in the presence of piperdine afforded New 8-Formyl-4-Methyl-7-Hydroxy Coumarin Derivatives (7a-o). Their structures were characterized by IR, $^1H$ and $^{13}C$ NMR and Mass spectral and elemental analysis data.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.17 no.1
• /
• pp.126-130
• /
• 2004

Objectives; Bioassay-directed fractionation of the dried roots of Salvia miltiorrhiza led to the isolation of abietane tanshinones, crptotanshinone and dihydrotanshinone. Methods: Their structures were elucidated using 1H-and 13C-NMR, UV, IR and mass spectral analysis. Result and Conclusions : These compounds exhibited a moderate antimicrobial activities against Staphylococcus epidemidis, Staphylococcus aureus, Staphylococcus pyogene. Actinobacillus actinomycetemcomitans, Escherichia coil, Enterbacter cloacae, Pseudomonas aeruginosa, Citrobacter freundii, and Samonella typhimurium.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.3
• /
• pp.501-505
• /
• 2010

1-Acetyl-$\beta$-carboline was isolated as an anti-MRSA agent from the fermentation broth of a marine actinomycete isolated from marine sediment. The producing strain was identified to be Streptomyces sp. by phylogenetic analysis of the 16S rRNA gene sequence. The anti-MRSA agent was isolated by bioactivity-guided fractionation of the culture extract by solvent partitioning, ODS open flash chromatography, and purification with a reversed-phase HPLC. Its structure was elucidated by extensive 2D NMR and mass spectral analyses. Combination of 1-acetyl-$\beta$-carboline with ampicillin exhibited synergistic antibacterial activity against MRSA.

• Korean Journal of Pharmacognosy
• /
• v.24 no.1
• /
• pp.32-37
• /
• 1993

Phytochemical studies of the root of Aristolochia contorta afforded an unidentified N-glycoside rarely found in natural products. It's structure was elucidated as 8-desmethoxy-aristolactam $N-{\beta}-D-glucopyranoside$ by spectral data and chemical analysis. 6-Hydroxy-8-desmethoxy-aristolactam $N-{\beta}-D-glucopyranoside$, aristolactam I and aristolactam AII were also isolated from the same source. $^{13}C-NMR$ spectra were first assigned and the result confirmed N-C-O-glycosidic linkages in the glycosides.