• 대한화장품학회지
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• 제23권3호
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• pp.86-91
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• 1997

Some natural polyhydroxy aromatic compounds have inhibitory activity against tyrosinase, key enzyme for formation of melanin pigment. We examined the structure-activity relationship of the natural polyhydrowy aromatic compounds and synthesized a number of new derivetives through various methods. Skin lightening effects of these compounds were examined through inhibition of mushroom tyrosinase and inhibitory of melanogenesis on B-16 melanoma cells. These new compounds showed strong inhibitory activity against tyrosinase. Good lightening effects sue to inhibition of melanogenesis were observed from several resorcinol and pyrogallol derivatives. In toxicological tests such as skin primary irritation and sensitization, the above compounds were sufficiently safe for cosmetic use.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.185-185
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• 1998

As part of our continuing attempts to evaluate biologically active compounds from fruiting bodies of cultivated fungus of Paecilomyces japonicus Yasuda, we conducted series of experiments on various fractions and compounds isolated by systematic fractionations. Our main efforts were concentrated on searching for compounds showing antitumor activities, which were tested on mice carrying Sarcoma-180 ascitic tumor. The antitumor activity was assessed by the life spans after these mice were administered Lp. with test compounds for consecutive 20 days. One of two pure compounds, which we have isolated to date, demonstrated significant prolongation of life span. ( Mean Survival Time: 30.3 days compared to that of control: 23.6 days). Structural analysis showed that this compound corresponds to D-mannitol. On the other hand, Ergosterol, another isolated pure compound didn't show efficient antitumor activity. We also obtained water-soluble fractions containing protein-bound polysaccharides and n-butantol fractions, which showed strong antitumor activities, 35.4(150%) and 32.1(136.0%) days of MST, respectively. In SRB assay, however, the test materials didn't show any toxic effects, but the level of acid phosphatase increased significantly when they were applied in cultured macrophage in vitro. Therefore, we concluded that antitumour activities might be attributed to immunostimulating rather than cytotoxic effects. Further experiments are underway to purify and structurally characterize new antitumour compounds from the active fractions.

• Natural Product Sciences
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• 제28권2호
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• pp.45-52
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• 2022

The identification of Plasmodium falciparum enoyl acyl-carrier protein reductase (pfENR) is considered as a potential biological target against malaria. Trema orientalis is considered a rich source of phytochemicals useful in malaria treatment. This study evaluated the in-vitro inhibitory activity of the extract and isolated compounds of T. orientalis leaf; the isolated compounds and the analogues of the most active compound were subjected to in-silico molecular docking studies on pfENR. The methanolic extract of T. orientalis was subjected to repeated chromatographic separation which led to the isolation of some compounds. The isolated compounds from the plant were examined for their antimalarial activity using β-hematin inhibition assay. Virtual screening via molecular docking and ADMET studies were conducted to gain insight into the mechanism of binding of ligand and to identify effective pfENR inhibitors. The isolated compounds and the analogues of the most active isolates were gotten from PubChem library for use in docking study. Hexacosanol and β-sitosterol showed inhibition of the β-hematin formation. The docking results showed that hexacosanol, β-sitosterol and the analogues of β-sitosterol displayed binding energy ranging between -6.1 kcal/mol and -11.6 kcal/mol. Sitosterol glucoside has the highest docking score. Some of the ligands showed more binding affinity than known bioactive compounds used as reference. Analogues of β-sitosterol has been shown to be potential inhibitors of pfENR, therefore, the findings from this study suggest that sitosterol glucoside and ergosterol peroxide could act as antimalarial agents after further lead optimisation investigations.

• 대한화학회지
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• 제52권5호
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• pp.583-587
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• 2008

• 대한화학회지
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• 제54권1호
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• pp.169-173
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• 2010

• Natural Product Sciences
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• 제19권3호
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• pp.242-250
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• 2013

The autophagy-lysosomal pathway is an important protein degradation system, and its dysfunction has been implicated in a number of neurodegenerative diseases, including Parkinson's disease. Raphani Semen, one of the herbs of Yeoldahanso-tang (YH), has neuroprotective effects via the autophagy pathway. The activity-guided method was used to isolate and identify the components of Raphani Semen. In this experiment, the total extract of Raphani Semen was partitioned to n-butanol, methylene chloride, and water fractions. Flow cytometry data showed that only the water fraction showed autophagy-inducing activity in vitro. Compounds 1 and 2 were isolated from this water fraction by preparative HPLC separation. The structures of compounds 1 and 2 were identified as stachyose and raffinose, respectively, by the analysis of various spectral data ($^1H$ NMR, $^{13}C$ NMR, and MS) and comparisons with standard stachyose and raffinose. Of these two compounds, raffinose showed autophagy-inducing activity in PC12 cells through the mTOR pathway.

• 한국환경보건학회지
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• 제32권6호
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• pp.566-570
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• 2006

Exposure to ultraviolet B(UVB) radiation causes skin inflammation such as pigmentation and the induction of cyclooxygenase-2(COX-2) gene expression. In this study, we investigated the effect of natural extracts from Tea, EGb 761 and Korean red ginseng(KRG), on the pigmentation and expression of COX-1 and COX-2 mRNA in UVB-irradiated C57BL/6 mice. Before UVB irradiation, the skin color was significantly showed the lightening effect by topical application of natural compounds (p<.05). In the case of UVB irradiated mice, we observed a decrease in pigmentation by compounds (p<.05). In irradiated skin, COX-1 mRNA expression is not changed following UVB irradiation, but COX-2 gene increases. Also, natural compounds lowered mRNA levels of COX-2. Therefore, these results suggest that COX-2 mRNA increases by UVB irradiation. Also, Tea, EGb 761 and KRG as a topical application may inhibit skin pigmentation and modulate COX-2 mRNA level.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.174-174
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• 1998

Twelve different derivatives were synthesised from chitin/chitosan[1, 2, 3]. Their structures have been determined by different physical methods. The bioassay screening on antifungal and antibacterial activities of all these compounds showed that most of them had significant activity and they can inhibite the growth of some fungi and bacterias : E. coli, S. pyogenes, F. oxysporum, P. oryzae, that caused the spoilage of fresh fruits and foods. Furthermore, all of these compounds are non-toxic (LD$\_$50/>50g/kg) and can be applied for food preservation.

• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.357-362
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• 2008

A method for synthesizing o-carborane substituted tetrahydroisoquinolines containing a polar functional group such as sulfamide, sulfonic, or phosphoric acid on the nitrogen atom of the piperidine ring, starting from arylethylamine, N-(2-arylethyl)sulfamide, N-(2-arylethyl)sulfamic acid or 2-arylethylamidophosphate, is described. In vitro studies showed the desired compounds 10, 15, 19, and 25 synthesized accumulate to high levels in B-16 melanoma cells with low cytotoxicity.

• Natural Product Sciences
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• 제8권4호
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• pp.147-151
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• 2002

In the course of our work on anti-platelet constituents from plants, eight phenolic compounds, $({\pm})-syringaresinol$ (1), 4-hydroxybenzaldehyde (2), 4-hydroxybenzoic acid (3), vanillic acid (4), 4-hydroxy cinnamic acid (5), quercetin 3-O-rhamnoside (6), rutin (7), and quercetin $3-(2^G-rhamnosylrutinoside)$ (8) were isolated from the methanol extract of the leaves of Magnolia obovata. The compounds were identified based on the spectroscopic data. Compound 2, 3, 5, 6, 7 and 8 were isolated for the first time from genus Magnolia. 1 and 6 showed same order of inhibitory potencies as acetylsalicylic acid (ASA) to rat platelet aggregation induced by all the stimulators tested. The remaining six compounds showed only mild effects.