Kap Duk Lee

Unique X-ray Sheet Structure of 1,8-Bis(imidazolium) Anthracene and Its Application as a Fluorescent Probe for DNA and DNase

A new imidazolium anthracene derivative 1 was synthesized, and its unique X-ray crystal structure was examined. In aqueous solutions, probe 1 exhibited a selective fluorescent quenching effect only with DNA among various anions including the nucleotides investigated. This probe was further applied to monitor the activity of DNase.

Mycosynthesis: Antibacterial, antioxidant and antiproliferative activities of silver nanoparticles synthesized from Inonotus obliquus (Chaga mushroom) extract

In the present study, silver nanoparticles (AgNPs) were rapidly synthesized from silver nitrate solution at room temperature using Inonotus obliquus extract. The mycogenic synthesized AgNPs were characterized by UV-Visible absorption spectroscopy, Fourier transform infrared (FTIR), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and atomic force microscopy (AFM). SEM revealed mostly spherical nanoparticles ranging from 14.7 to 35.2nm in size. All AgNPs concentrations showed good ABT radical scavenging activity. Further, AgNPs showed effective antibacterial activity against both gram negative and gram positive bacteria and antiproliferative activity toward A549 human lung cancer (CCL-185) and MCF-7 human breast cancer (HTB-22) cell lines. The samples demonstrated considerably high antibacterial, and antiproliferative activities against bacterial strains and cell lines.

Kinetics of thermal bleaching reaction of the photomerocyanine form of spironaphthooxazine

Abstract The thermal bleaching reactions of photomerocyanine (PMC) form of spironaphthooxazine (SNO) were investigated in various temperatures and solvents using laser flash photolysis. The thermal decay rate of PMC for SNO markedly decreases as temperature decreases and generally increases with solvent polarity. The solvent effect on the rate constant was well explained by using the π ∗ -scale. The activation energy and activation entropy also increase with the solvent polarity and the isokinetic relation has been observed. The combined results are interpreted in terms of dissociation of solvated PMC complex and/or ordered solvent structure around PMC molecules. Based on the experimental results, the potential energy surface along the reaction path in the ground state has been proposed.

Synthesis and photochemical protein crosslinking studies of hydrophilic naphthalimides

A mixture of 4-alkylamino-1,8-naphthalimides has previously been reported to exhibit potential utility as a photochemical tissue-bonding reagent. In order to determine which constituents of the mixture were responsible for the observed tissue bonding and to facilitate study of the mechanism, we have synthesized each of the primary constituents of the mixture. Each naphthalimide synthesized has been demonstrated to photochemically crosslink proteins.

Glyscavins A, B and C, New Phenolic Glycoside Antioxidants Produced by a Fungus Mycelia sterilia F020054

Three new phenolic glycosides designated glyscavins A (1), B (2), and C (3) were isolated from the culture broth of a fungal strain Mycelia sterilia F020054. Structural elucidation of the compounds was based on the NMR and MS spectroscopic analyses. Glyscavins A, B and C exhibited higher free radical scavenging activity on superoxide and 2,2′-azinobis(3-ethylbenzothialozinesulfonic acid) cation radical (ABTS·+) than butylated hydroxyanisole (BHA).

Dioscorea batatas Rhizome-Assisted Rapid Biogenic Synthesis of Silver and Gold Nanoparticles

Development of biologically inspired experimental process for the synthesis of nanoparticles is an important branch of nanotechnology. Here the authors have synthesized silver and gold nanoparticles (AgNPs and AuNPs) by using rhizome extract of Dioscorea batatas at 50°C (AuNps), AgNPs was carried out at 80°C as well as room temperature (25°C). The reductions of Ag and Au ions were observed by the color changes from colorless to brownish yellow, and dark yellow and dark red wine, respectively. The reaction was followed with the help of UV-visible spectrometer. The synthesized nanoparticles were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscope analysis. The authors did not find, formation of gold nanoparticles at room temperature. Furthermore, this green biogenic approach is rapid and simple alternative to chemical synthesis methods.

Synthesis, Anticancer and Antioxidant Activity of Novel Carbazole-based Thiazole Derivatives

GRAPHICAL ABSTRACT Abstract A series of carbazole-based thiazole derivatives were synthesized and characterized. The title compounds were evaluated for their cytotoxicity against three cancer cell lines A549, MCF-7, and HT29 by MTT assay. Among several thiazole derivatives, compounds 4-(4-bromophenyl)-2-(2-((9-ethyl-9H-carbazol-3-yl)methylene)hydrazinyl)thiazole (3f) and 2-(2-((9-ethyl-9H-carbazol-3-yl)methylene)hydrazinyl)-4-(4-nitrophenyl)thiazole (3g) are found to display significant cytotoxicity against three cancer cell lines. These compounds have also been tested for antioxidant activity and are found to exhibit higher antioxidant activity than that of the standard BHT.

Synthesis and Bioactivity of Novel Phenothiazine-Based Thiazole Derivatives

GRAPHICAL ABSTRACT Abstract A series of phenothiazine-based thiazole derivatives were synthesized and evaluated for their cytotoxicity against three cancer cell lines A549, MCF-7, and HT29 by MTT assay. Among several thiazole derivatives, compound 3d against HT29 cells and 3g against MCF-7 cells are found to display good cytotoxicity. These compounds have also been tested for antifungal and antioxidant activity. Some of these compounds exhibited significant antifungal activity and compound 3j was found to exhibit almost equivalent antioxidant activity as that of BHT.

A Simple and Catalyst-Free One-Pot Synthesis of α-Aminophosphonates in Polyethylene Glycol

Abstract A simple and efficient method has been developed for the one-pot synthesis of α-aminophosphonates using polyethylene glycol (PEG) as a green reaction media. GRAPHICAL ABSTRACT

AgNPs: Green Synthesis, Characterization, Antimicrobial, and Cytotoxicity Studies of Methanol and Aqueous Extracts of Pseudocydonia sinensis (Chinese Quince) Fruit

Silver nanoparticles (AgNPs) are among the emerging nanoproducts that have gained increasing interest in the field of nanomedicine due to their unique properties and obvious therapeutic potential in treating a variety of diseases. The authors used a methanol and aqueous fruit extracts of Pseudocydonia sinensis to synthesize AgNPS. To their knowledge, this is the first report where Pseudocydonia sinensis fruit was found to be a suitable plant source for the green synthesis of AgNPs. The AgNPs were characterized by UV-visible spectroscopy, transmission electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, and Fourier transform infrared spectroscopy. Green synthesized Meoh-AgNPs and aqueous-AgNPs were found toxic against S. aureus (KCTC 1916), B. substilis (lab culture), E. coli (KCTC 2441), C. albicans (lab culture), and S. cerevicae (KCCM 1020). MTT assay showed (B16/F10 melanoma cancer cell line) minimum cell inhibition (1.01%) was observed at 0.12mM and maximum cell inhibition (81.85%) at 1mM. Meoh-AgNPs appeared to be more active than aqueous-AgNPs. Furthermore, this green synthesis is a rapid and simple alternative to chemical synthesis.