• Natural Product Sciences
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• 제21권4호
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• pp.255-260
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• 2015

Two new thiodiketopiperazines (TDKPs), designated graphiumins I (1) and J (2), were isolated from the culture broth of the marine-derived fungus Graphium sp. OPMF00224 by solvent extraction, silica gel column chromatography, and HPLC. Their absolute structures were elucidated by spectroscopic analyses (1D and 2D NMR data, ROESY correlations, and CD data) and chemical methods. They were found to be structurally rare TDKPs with a phenylalanine-derived indolin substructure. Compounds 1 and 2 inhibited yellow pigment production by methicillin-resistant Staphylococcus aureus (MRSA) with $IC_{50}$ values of 63.5 and $76.5{\mu}g/ml$, respectively, without inhibiting its growth, even at $250{\mu}g/ml$.

• 생명과학회지
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• 제18권9호
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• pp.1219-1224
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• 2008

Neural crest는 신경계의 발생과정에서 생긴 특정화된 외배엽으로서 말초신경계(peripheral nervous system)의 모든 sensory cells과 fibers, 자율신경계의 대부분의 peripheral cells, unipolar spinal ganglion cell, cranial sensory ganglia, peripheral nerve의 neurolemmal sheath cells, ganglia의 capsule cells, sympathetic ganglia, chromaffin cells, pigment cell 등이 분화한다. Fish의 경우는 melanin을 가지고 있는 melanophores, yellow pigment를 가지고 있는 xanthopores, reflecting platelets를 가지고 있는 iridophores등 3가지의 pigment-producing cell을 가지고 있다. 다양한 pigement들의 deposition, distribution에 의해 Fish와 amphibian에서 볼 수 있는 수많은 color와 pattern이 만들어지게 된다. Embryonic neural crest가 patterning을 연구하기에 아주 좋은 모델임에도 불구하고, choromatophores의 cell-signaling mechanism에 관한 연구는 거의 없는 실정이다. 본 연구에서는 melanosomes의 melanocyt로의 이동기작과 이들의 dentiritic processe를 밝히기 밝히기 위해 phosphorylaion assay와 투과형 전자 현미경(transmission electron microscope)등을 이용한 다양한 실험들을 토대로, Lithium에 의해 유도되는 morphological alteration에 IP cell signaling pathway에 의해 조절되는 단백질의 하나인 55-kDa단백질의 인산화가 중요한 역할을 함을 밝혔다.

• BMB Reports
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• 제34권3호
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• pp.189-193
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• 2001

Curcumin a yellow pigment from Curcuma Tonga, has been known to possess antioxidative and anticarcinogenic properties, as well as to induce apoptosis in some cancer cells. There have been, however, several contradictory reports that hypothesized curcumin (a hydrophobic molecule) can bind a membrane Gpid bilayer and induce nonspecific cytotoxicity in some cell lines. Why curcumin shows these contradictory effects is unknown. In A-431 cells, growth inhibition by curcumin is due mostly to the specific inhibition of the intrinsic tyrosine kinase activity of the epidermal growth factor receptor, as reported earlier by Korutla et al. Thus, we assumed that the cell death of A-431 by curcumin might be due to the specific induction of apoptosis. In this paper we clearly show that curcumin induces apoptosis in A-431 cells. The cureumin-induced cell death of A-431 exhibited various apoptotic features, including DNA fragmentation and nuclear condensation. Furthermore, the curcumin-induced apoptosis of A-431 cells involved activation of caspase-3-like cysteine protease. Involvement of caspase-3 was further confirmed by using a caspase-3 specific inhibitor, DEVD-CHO. In another study, decreased nitric oxide (NO) production was also shown in A-431 cells treated with curcumin, which seems to be the result of the inhibition of the iNOS expression by curcumin, as in other cell lines. However, 24 h after treatment of curcumin there was increased NO production in A-431 cells. This observation has not yet been clearly explained. We assumed that the increased NO production may be related to denitrosylation of the enzyme catalytic site in caspase-3 when activated. Taken together, this study shows that the cell death of A-431 by curcumin is due to the induction of apoptosis, which involves caspase-3 activation.