Nack-Do Sung

Synthesis andin vitro cytotoxicity of cinnamaldehydes to human solid tumor cells

Cinnamaldehydes and related compounds were synthesized from various cinnamic acids based on the 2′-hydroxycinnamaldehyde isolated from the bark ofCinnamomum cassia Blume. The cytotoxicity to human solid tumor cells such as A549, SK-OV-3, SK-MEL-2, XF498 and HCT15 were measured. Cinnamic acid, cinnamates and cinnamyl alcohols did not show any cytotoxicity against the human tumor cells. Cinnamaldehydes and realted compounds were resistant to A549 cell line up to 15 μg/ml. In contrast, HCT15 and SK-MEL-2 cells were much sensitive to these cinnamaldehyde analogues which showed ED50 values 0.63-8.1 μg/ml. Cytotoxicity of the saturated aldehydes was much weak compared to their unsaturated aldehydes. From these studies, it was found that the key functional group of the cinnamaldehyde-related compounds in the antitumor activity is the propenal group.

New sesquiterpene-monoterpene lactone, artemisolide, isolated from Artemisia argyi

Abstract A new sesquiterpene–monoterpene lactone, artemisolide, was isolated from the aerial parts of Artemisia argyi. The structure of artemisolide was elucidated by spectroscopic data including HMBC and NOESY. The structure was confirmed by X-ray crystallographic analysis. Artemisolide exhibited in vitro cytotoxic activity with GI50 values of 2–8 μM against cancer cell lines.

Some fungal endophytes from vegetable crops and their anti‐oomycete activities against tomato late blight

Aims:  To isolate endophytic fungi from vegetable plants and examine their in vivo anti‐oomycete activity against Phytophthora infestans in tomato plants.

Bikaverin and fusaric acid from Fusarium oxysporum show antioomycete activity against Phytophthora infestans

Aims:  To isolate and identify antioomycete substances from Fusarium oxysporum EF119 against Phytophthora infestans and to investigate their antimicrobial activities against various plant pathogenic bacteria, oomycetes and true fungi.

Self-assembly of one-dimensional coordination polymer from nickel(II) macrocyclic complex and 2,6-pyridinedicarboxylate ligand

Abstract The reaction of [Ni(L)(H2O)2]Cl2 (L=2,5,9,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane) with 2,6-pyridinedicarboxylate (pdc) generates one-dimensional coordination polymer [Ni(L)(pdc)]·H2O (1). In the polymeric framework, the nickel(II) ion has an octahedral geometry and is bridged by two pdc ligands. The magnetic susceptibility measurement for 1 exhibits a weak antiferromagnetic interaction ( J=−1.04(3) cm −1 ; H=−JΣSi·Si+1) between the S=1 nickel(II) paramagnetic centers.

Biflavonoids inhibited phosphatase of regenerating liver-3 (PRL-3)

Two biflavonoids, ginkgetin (1) and sciadopitysin (2), were isolated from the MeOH extract of the young branches of Taxus cuspidata, which inhibited phosphatase of regenerating liver-3 (PRL-3) with IC50 values of 25.8 and 46.2 μM, respectively. This is the first report on PRL-3 inhibitors, isolated from natural sources.

Suppression of pine wilt disease by an antibacterial agent, oxolinic acid

BACKGROUND Pine wilt disease (PWD) is very complex and has been reported to be caused by pine wood nematode, Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle, and its accompanying bacteria. However, there is no report on the control of PWD by antibacterial agent. The present study was performed to investigate disease control efficacy of antibacterial agents against PWD. RESULTS Among six antibacterial antibiotics tested, oxolinic acid (OA) showed the strongest antibacterial activity against five bacteria isolated from three strains of pine wood nematode. In in vivo assay, it effectively suppressed the development of PWD in three-year-old seedlings of Pinus densiflora Sieb. & Zucc.; it showed 71% control when injected at 3 mg per seedling. A mixture of OA and the nematicidal agent abamectin (Ab) showed higher disease control efficacy against PWD than either OA or Ab alone. In addition, OA alone and a mixture of OA and Ab also controlled PWD in approximately 20-year-old pine trees under field conditions. CONCLUSION This is the first report on the suppression of PWD by OA. The result strongly indicates that PWD could be controlled by antibacterial antibiotic alone and a combination of antibacterial and nematicidal agents.

Nematicidal Activity of Bikaverin and Fusaric Acid Isolated from Fusarium oxysporum against Pine Wood Nematode, Bursaphelenchus xylophilus

Pine wood nematode, Bursaphelenchus xylophilus, causes pine wilt disease in a number of Pinus species, which is one of the most serious plant diseases in forest, Korea. In the course of a search for nematicidal substances from endophytic fungi, Fusarium oxysporum EF119 out of the 23 fungal strains tested showed the strongest activity to B. xylophilus. Two nematicidal substances were isolated and identified as bikaverin and fusaric acid. Fusaric acid showed somewhat higher nematicidal activity against B. xylophilus than bikaverin; fusaric acid and bikaverin, at , killed B. xylophilus with mortality values of 50% and 43%, respectively. In addition, both compounds acted synergistically. This is the first report on the nematicidal activity of bikaverin and fusaric acid.

Synthesis, properties, and X-ray structure of [Cu(dpa)Cl2] (dpa = di-(2-picolyl)amine)

The mono(dpa)copper(II) complex [Cu(dpa)Cl2] (1) (dpa = di-(2-picolyl)amine) has been synthesized and structurally characterized. It crystallizes in the monoclinic system P21/n with a = 8.155(1), b = 12.560(1), c = 12.817(2) Å, β = 91.64(2)°, V = 1312.3(2) Å3, Z = 4. The copper atom is coordinated by three nitrogen atoms from the dpa ligand and two chlorides in a distorted square-pyramidal environment. Cyclic voltammetric data show that 1 undergoes the reversible one-electron oxidation to the Cu(III) and the reversible one-electron reduction to the Cu(I) state.

Anthraquinones, Cdc25B phosphatase inhibitors, isolated from the roots of Polygonum multiflorum Thunb.

Three anthraquinones, Cdc25B phosphatase inhibitors, were isolated from the methanolic extract of the roots of Polygonum multiflorum Thunb. (Polygonaceae). Anthraquinones, physcion (1), emodin (2), and questin (3), inhibited the enzymatic activity of Cdc25B phosphatase with IC50 values of 62.5, 30, and 34 µg mL−1, respectively. Emodin (2) and questin (3) strongly inhibited the growth of human colon cancer cells, SW620 with GI50 values of 6.1 and 0.9 µg mL−1, respectively. Commercially available anthraquinones, chrysophanol (4), and rhein (5) also inhibited Cdc25B phosphatase with IC50 values of 10.7 and 22.1 µg mL−1, respectively.