• Journal of the Korean Chemical Society
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• v.26 no.3
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• pp.172-178
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• 1982

A psoralen-DNA monoadduct analogue, 4',5'-dihydropsoralen (DHP) is synthesized and its photophysical properties such as fluorescence quantum yield (0.08), phosphorescence quantum yield (0.013), fluorescence lifetime (0.95ns), and phosphorescence lifetime(0.039s) were measured in ether solution and in frozen matrix state at 77K. The photocycloaddition reaction of DHP with tetramethylethylene(TME) was carried out in solution and in the frozen state. The major photoadduct was isolated and characterized by elemental analysis and physical methods such as UV, IR, NMR, and mass spectrometry. The major DHP-TME photoadduct was proved to be an 1 : 1 $C_4$-cycloadduct formed through 2 + 2 cycloaddition of the pyrone double bond of DHP to TME.

• Journal of the Korean Wood Science and Technology
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• v.28 no.3
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• pp.52-61
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• 2000

Black locust(Robinia pseudoacacia) and poplar(Populus alba ${\times}$ glandulosa) trees were collected, extracted with acetone-$H_2O$(7:3, v/v) after drying, fractionated with hexane, chloroform and ethylacetate, and freeze dried to get some brown powder. Each fraction of the powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluting solvents. The wood extractives of black locust contained (+)-leucorobinetinidin as flavan, robtin as flavanone and dihydrorobinetin as flavanonol, and robinetin as flavonol. The poplar bark extractives contained various kinds of phenolic compounds : (+)-catechin as flavan, naringeoin, eriodictyol, sakuranetin, aromadendrin and taxifolin as flavanonol, salireposide as salicin derivative, and minor compounds such as aesculin and p-coumaric acid. However, aesculin has not been reported as a constituent of the poplar bark in Korea yet. NMR and FAB-MS analyses were done to elucidate the structures of isolated phenolic constituents.

• Journal of the Korean Wood Science and Technology
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• v.28 no.3
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• pp.62-69
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• 2000

The bark of ash(Fraxinus rhynchophylla) and elm(Ulmus davidiana var. japonica) trees were collected, extracted with acetone-$H_2O$(7:3, v/v), fractionated with hexane, chloroform and ethylacetate, and freeze dried to give some dark brown powder. Each fraction of the powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. The ash bark contained a large amount of coumarin derivatives such as aesculetin and aesculin in addition to trace amount of ligstroside and oleuropein. Most of the elm bark extractive were (+)-catechin and its glycosides such as (+)-catechin-7-O-xylopyranose and (+)-catechin-7-O-apiofuranose in addition to a small amount of procyanidin B-3, a dimeric (+)-catechin. NMR and FAB-MS spectrometric analyses were performed to characterize the structures of isolated phenolic compounds.

• Journal of the Korean Chemical Society
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• v.47 no.2
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• pp.137-146
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• 2003

3-Hydroxybenzopyran[3,2-c]-[1]-benzopyran-6,7-diones (3) and 3-methoxycarbonylcoumarin (4) were prepared via condensation of 1 with resorcinol in the presence of sodium methoxide. The chemical behavior of 3 towards acetic anhydride, alkyl halides and diazonium chloride is described. The electron impact ionization mass spectra of compounds 4,5 and 6a,b show a weak molecular ion peak and a base peak of m/z 89, m/z 280. m/z 91 and m/z 120 resulting from a cleavage fragmentation respectively. The molecular ion of compounds 3, 6b, and 7a is a base peak of m/z 280, m/z 366 and m/z 488 respectively. Compound 7a give a characteristic fragmentation pattern with a two very stable fragmentation of m/z 383 and m/z 77.

• Journal of the Korean Applied Science and Technology
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• v.40 no.6
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• pp.1373-1380
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• 2023

This study investigated the effects of coumarin, a flavonoid known for various physiological activities like antiviral, anticancer, and antibacterial properties, on anti-oxidants and anti-inflammatory processes, aiming to explore its application in functional cosmetics. The results are as follows: Cell toxicity experiments using RAW 264.7 cells showed no significant cytotoxicity for coumarin at any concentration, indicating its safety for skin application. Observing coumarin's antioxidant activity through DPPH radical scavenging showed concentration-dependent effectiveness, though not significantly varied with concentration. The inhibition of silica-induced ROS production in cells was concentration-dependent. Both NO production inhibition and histamine release measurements showed concentration-dependent suppression. These findings suggest that Coumarin can be effectively used as a natural ingredient in cosmetic development for its antioxidant and anti-inflammatory properties.

• Journal of Digital Convergence
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• v.12 no.4
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• pp.419-425
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• 2014

The objective of this study is to estimate the inhibition of skin melanin formation by extract of Angelica koreana and Cnidium monnieri and the possibility of functional cosmetic materials through anti-irritation and stability test. The extract used in this experiment is White-$AK^{TM}$ and the INCI name is Osthole. The main component of White-$AK^{TM}$ was identified as coumarin and EC50 value was 2.7ppm by mouse melanoma B 16 cell test. White-$AK^{TM}$ showed inhibitory effects 100 times lower concentration than arbutin. The main mechanism for skin whitening effect thought to be inhibition of tyrosinase-related gene expression. The basic essence formulation of White-$AK^{TM}$ 5% solution applied to the skin showed the effect of relieving skin irritation. White-$AK^{TM}$ in an opaque container, under UV conditions for 4 weeks, and showed close to 100% recovery and 97% recovery under $50^{\circ}C$ for 4 weeks. Therefore, it is thought that White-$AK^{TM}$ which helps skin whitening, relieving skin irritation and stable in UV condition is able to be used as the functional component in the cosmetic formulation.

• Journal of Life Science
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• v.28 no.9
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• pp.999-1006
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• 2018

Obesity is epidemic worldwide and has reportedly been linked to the progression of several metabolic and cardiovascular diseases. The natural products are decreasing the side effects of medicines used for obesity and also have health benefits dut to their numerous bioactive compounds. In this context, Artemisia scoparia is a widespread plant that has been suggested as possessing various types of bioactivity. In this study, the crude extract from A. scoparia (ASE) was tested for its ability to suppress adipogenesis in mouse 3T3-L1 pre-adipocytes. The molecular pathway by which ASE affects differentiation of 3T3-L1 cells was also investigated. The introduction of ASE to differentiating 3T3-L1 pre-adipocytes resulted in suppressed adipogenesis, as confirmed by decreased intracellular lipid accumulation. The differentiating cells treated with 10 and $100{\mu}g/ml$ of ASE showed 21.9 and 29.0% less lipid accumulation, respectively, than untreated adipocytes. In addition, the results indicated that ASE treatment lowered the expression of the adipogenesis-related factors $PPAR{\gamma}$, $C/EBP{\alpha}$, and SREBP-1c. Furthermore, treating with ASE notably decreased levels of phosphorylated p38, ERK, and JNK in 3T3-L1 adipocytes. These results indicate that ASE exhibits significant anti-adipogenesis activity by downregulating the MAPK and $PPAR{\gamma}$ pathways during the differentiation of 3T3-L1 pre-adipocytes. Therefore, A. scoparia may be a potential source of natural products against obesity.

• Journal of Life Science
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• v.30 no.11
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• pp.990-998
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• 2020

This study was conducted to evaluate the hair-growth promotion effect in C57BL/6 mice of a new substance mixed with Allium cepa (red)-bioconversion extract and Angelica gigas Nakai. The ethanol extract of Allium cepa (red) was bioconverted through the use of the Bacillus subtilis KJ-3 (BS3) strain, which was named Red-BCQ. The quercetin content of Red-BCQ increased by about 7.4-fold after bioconversion. Angelica gigas Nakai extract (Agnex) contains a large amount of coumarins such as decursin (D) and decursinol angelate (DA). A 1 mg portion of Agnex contained 0.4146 mg of D and 0.3659 mg of DA. Minoxidil has been known to promote hair growth. In this study, the hair-growth promotion effects of Red-BCQ, Agnex, and a mixture of both Red-BCQ and Agnex were compared with 5% minoxidil. Twenty-five mice were divided into five experimental groups including saline (CON), 5% minoxidil (PCON), Red-BCQ (RA), Agnex (AG), and a Red-BCQ-Agnex mixture (RAG)-treated group. Samples were administered orally once a day at a fixed time for 4 weeks. Hair growth was monitored by photograph at 7, 14, 21, and 28 days. We also observed 5α-reductase, alkaline phosphatase (ALP), γ-glutamyl transpeptidase (γ-GT), insulin-like growth factor (IGF)-1, transforming growth factor (TGF)-β1, antioxidant enzyme, and the hair follicles of the skin tissue. In all the results, the RAG-administered group showed greater antioxidative and hair-growth promotion effects than the other groups. These data suggest that RAG has potent stimulating activity on hair growth in C57BL/6 mice.

• YAKHAK HOEJI
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• v.42 no.4
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• pp.422-430
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• 1998

In order to study the effects of Rhei rhizoma, Ephedrae herba and Scutellariae radix on hepatic metabolism, we examined the pretreatment effect of those on the metabolism of 7-e thoxycoumarin (EC). Water extracts (1g/kg) of Rhei rhizoma, Ephedrae herba and Scutellariae radix were administered orally to rats for 7 days, respectively. Livers were then isolated and perfused with 100mcM EC for 2 hours. The metabolites of EC, 7-hydroxycoumarin, sulfate conjugate and glucuronide conjugate were measured in the perfusates. The amount of glucuronide conjugates was decreased in Rhei rhizoma pretreated rats (p<0.01), however, 7-hydroxycoumarin was increased in Ephedrae herba pretreated rats (p<0.01). We examined whether the change of enzyme activity is related to the change of cytochrome P4501A1 and P4502B1 mRNA level in the perfused rat liver, which are responsible for EC metabolism. CYP1A1 and CYP2B1 mRNA level was increased, which was was not statistically significant with rhei rhizoma nor ephedrae herba pretreatment. We also assessed the hepatotoxicity of Rhei rhizoma, Ephedrae herba and Scutellariae radix. The activities of ALT and AST were assayed at 24 hours after 7 days administration. Only the ratio of ALT over AST was increased in ephedrae herba pretreated rats (p<0.05). Lipid peroxidation was increased in Rhei rhizoma treatment (p<0.05), while histopathological examination performed after liver perfusion did not show any difference compared with vehicle treatment. These results suggest that Ephedrae herba pretreatment increases the o-deethy-lation of 7-ethoxycoumarin in rats, which may be mediated by CYP1A1 mRNA induction.

• Journal of Life Science
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• v.32 no.9
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• pp.734-741
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• 2022

Currently, around 40 million people worldwide are living with human immunodeficiency virus (HIV) infection making HIV a critical global health risk. Present therapies for HIV infection consist of drug cocktails that target different steps of the HIV life cycle to prevent infection, replication, and release of the virus. Due to its mutating nature, drug resistance coupled with side-effects of long-term drug use, novel strategies, and pharmaceuticals to treat and manage HIV infection are constant needs and continuously being studied. Plants allocate a major repertoire of chemical diversity and are therefore regarded as an important source of new bioactive agents that can be utilized against HIV. Since the early 1990s, upon recommendations of the World Health Organization, numerous studies reported phytochemicals from different structural classes such as flavonoids, coumarins, tannins and terpenes with strong inhibitory effects against HIV infection. The present review gathered and presented recent research (2021-present) on plant extracts and phytochemicals that exhibit anti-HIV properties with the aim of providing insights into future studies where ethnomedical and underutilized plant sources may yield important natural products against HIV. Considering the relation and importance of HIV treatment with current viral infection risks such as SARS-CoV-2, screening plants for anti-HIV agents is an important step towards the discovery of novel antivirals.