• Proceedings of the PSK Conference
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• 2003.04a
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• pp.260.2-261
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• 2003

Four known flavonoids and two galloyl glucoses isolated from the stem-bark of Juglans mandshurica (Juglandaceae), namely taxifolin (1), afzelin (2), quercitrin (3), myricitrin (4), 1,2,6-trigalloylglucose (5), and 1,2,3,6-tetragalloylglucose (6), were evaluated for their anti-complement activity against complement system. (omitted)

• Natural Product Sciences
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• v.15 no.1
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• pp.12-16
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• 2009

Phytochemical investigation of Metasequoia glyptostroboids leaves resulted in the isolation of ten compounds. The structures were determined to be isoquercitrin (1), quercitrin (2), myricitrin (3), amentoflavone (4), sciadopitysin (5), isoginkgetin (6), 2,3-dihydrosciadopitysin (7), 2,3-dihydroisoginkgetin (8), $3{\beta}$-acetoxy-8(17),13E-labdadien-15-oic acid (9) and $\beta$-sitosterol (10) by spectroscopic analyses. Isoquercitrin (1) was isolated from this plant for the first time.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.372.1-372.1
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• 2002

AIzelin (1) and quercitrin (2) isolated from the EtOAc-soluble fraction of the leaves of Litsea japonica Jussieu (Lauraceae) showed inhibitory activity against classical pathway complement system with 50% inhibitory concentration ($IC_{50}$/) values of 112.2 and 198.2 $\mu\textrm{g}$/$m\ell$. respectively. For the structure-activity relationship of flavonoids on anti-complement system. myricitrin (3) from JUQ/ans mandshurica Maximowicz (Juglandaceae) also tested anti-complement activity. while this was devoid of any significant activity. (omitted)

• Journal of the Korean Wood Science and Technology
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• v.34 no.6
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• pp.51-60
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• 2006

Juglans mandshurica barks were collected, extracted with acetone-$H_2O$ (7:3, v/v), fractionated with n -hexane, $CH_2Cl_2$, and EtOAc, and freeze dried to give some dark brown powder. The EtOA cand $H_2O$ soluble fractions were chromatographe d on a Sephadex LH-20 column using $H_2O$-MeOH and EtOH-hexane mixture as eluents. Spectrometric analysis such as NMR and MS, including TLC,were performed to characterize the structures of the isolated compounds. From the EtOAc and $H_2O$ soluble fractions, three flavanols (1~3), three flavonols (4~6) and five flavonol glycosides (7~11) were isolated and elucidated.

• Natural Product Sciences
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• v.22 no.1
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• pp.64-69
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• 2016

A method for simultaneously identifying antioxidative compounds was developed using time-based LC-MS coupled with DPPH assay regardless of the time consuming process. The methanolic extract of Polygonum aviculare (Polygonaceae) showed significant DPPH radical scavenging activity. Time-based DPPH assay for simultaneous identification of active compounds from the extracts of P. aviculare was used. Major peaks of ethyl acetate fraction of P. aviculare showed high DPPH radical scavenging activity. A simple phenolic compound (1) and six flavonoids (2-7) were isolated from the ethyl acetate fraction of P. aviculare by silica gel and sephadex LH-20 column chromatography. The structures of seven compounds were determined to be protocatechuic acid (1), catechin (2), myricitrin (3), epicatechin-3-O-gallate (4), avicularin (5), quercitrin (6), and juglanin (7) based on the analysis of the $^1H$-NMR, $^{13}C$-NMR and ESI-MS data. All compounds exhibited significant antioxidant activity on DPPH assay and active compounds were well correlated with predicted one.

• Korean Journal of Pharmacognosy
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• v.45 no.3
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• pp.220-226
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• 2014

Diospyros lotus has been cultivated for its edible fruits and leaves which are considered for its medicinal importance. The aim of this study was to evaluate the anti-melanogenesis of ethyl acetate (EA) fractions from D. lotus leaves in B16 cells. The order of the total polyphenol content with regard to the different solvent fractions from D. lotus leaves was EA>butanol>metahanol>chloroform>n-hexane. The major compounds of EA fraction from D. lotus leaves by HPLC analysis were myricitrin and myricetin. Cellular TYR activity and melanin content in response to treatment with 100 mg/mL of EA fraction was inhibited more strongly than group treated with arbutin. Further, EA fraction exhibited significant anti-melanogenesis effects by reducing the levels of microphthalima-associated transcription factor (MITE), inhibiting the synthesis of TYR, tyrosinase-related protein-1 (TRP-1) and TRP-2. Therefore, EA fractions from D. lotus leaves may be a good source of skin-whitening agents in the future development of medicine-based trouble skin therapy.

• Journal of Plant Biotechnology
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• v.50
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• pp.27-33
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• 2023

Zizyphus jujube is a plant in the buckthorn family (Rhamnaceae) that has been the subject of research into antibacterial, antifungal and anti-inflammatory properties of its fruit and seed. However, few studies have investigated its leaves. In this study, the anti-inflammatory activity of ZJL (an extract of Z. jujube leaf) was evaluated to verify its potential as an anti-inflammatory agent and SARS-CoV-2 medicine, using nitric oxide (NO) assay, RT-PCR, SDSPAGE, Western blotting, and UHPLC/TOFHRMS analysis. We found that ZJL suppresed pro-inflammatory mediators such as NO, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and tumor necrosis factor α (TNF-α) in lipopolysaccharide (LPS)-induced RAW264.7 cells. ZJL acted by inhibiting NF-KB and MAPK signaling pathway activity. We also confirmed that ZJL contains a phenol compound and flavonoids with anti-inflammatory activity such as trehalose, maleate, epigallocatechin, hyperoside, catechin, 3-O-coumaroylquinic acid, rhoifolin, gossypin, kaempferol 3-neohesperidoside, rutin, myricitrin, guaiaverin, quercitrin, quercetin, ursolic acid, and pheophorbide a. These findings suggest that ZJL may have great potential for the development of anti-inflammatory drugs and vaccines via inhibition of NF-κB and MAPK signaling in LPS-induced RAW264.7 cells.

• Natural Product Sciences
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• v.21 no.3
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• pp.162-169
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• 2015

Hamamelis japonica (Hamamelidaceae), widely known as Japanese witch hazel, is a deciduous flowering shrub that produces compact clumps of yellow or orange-red flowers with long and thin petals. As a part of our ongoing search for phenolic constituents from this plant, eleven phenolic constituents including six flavonol glycosides, a chalcone glycoside, two coumaroyl flavonol glycosides and two galloylated compounds were isolated from the flowers. Their structures were elucidated as methyl gallate (1), myricitrin (2), hyperoside (3), isoquercitrin (4), quercitrin (5), spiraeoside (6), kaempferol 4'-O-β-glucopyranoside (7), chalcononaringenin 2'-O-β-glucopyranoside (8), trans-tiliroside (9), cis-tiliroside (10), and pentagalloyl-O-β-D-glucose (11), respectively. These structures of the compounds were identified on the basis of spectroscopic studies including the on-line LCNMR-MS and conventional NMR techniques. Particularly, directly coupled LC-NMR-MS afforded sufficient structural information rapidly to identify three flavonol glycosides (2 - 4) with the same molecular weight in an extract of Hamamelis japonica flowers without laborious fractionation and purification step. Cytotoxic effects of all the isolated phenolic compounds were evaluated on HCT116 human colon cancer cells, and pentagalloyl-O-β-D-glucose (11) was found to be significantly potent in inhibiting cancer cell growth.