• The Korea Journal of Herbology
• /
• v.31 no.5
• /
• pp.7-13
• /
• 2016

Objectives : Camellia sinensis (Theaceae) possesses a various beneficial effects such as free radical-scavenging, inactivation of urokinase in cancer cell proliferation, antibacterial, and hypotensive. Dental caries is one of the most common oral infectious disease in a human. Oral microorganisms play a significant role in the etiology of dental caries. An aberration to this ecology due to dietary habits, improper oral hygiene or systemic factors lead to an increase in cariogenic microorganisms. Cariogenic microorganisms like Streptococcus mutans and Streptococcus sobrinus encourage the accumulation and adherence of plaque biofilm by metabolizing sucrose into glucans. The purpose of this study was to investigate the antimicrobial activity of phenolic compounds of Camellia sinensis and R-carvone, monoterpenes, is can be found naturally in numerous essential oils, on Streptococcus mutans and Streptococcus sobrinus .Methods : The antimicrobial activity of these compounds was determined by the broth microdilution method and checkerboard dilution assay to investigate the potential synergistic effects of each five compounds of Camellia sinensis (C. sinensis) and R-carvone.Results : C. sinensis-isolated compounds and R-carvone were determined with MIC of more than 1,000 ㎍/mL. However, the combination test showed significant synergism against S. mutans and S. sobrinus, implicated in the lowered MICs.Conclusions : These results suggest that combinatory application of phenolic five compounds (theophyllin, l-theanine, epicatechin, epicatechin gallate, and caffeine) from C. sinensis and R-carvone has a potential synergistic effect and thus may be useful as a mouthrinse in helping control cariogenic microorganism.

• Food Science and Preservation
• /
• v.11 no.1
• /
• pp.63-70
• /
• 2004

The antimicrobial substances from Rhodiola sachalinensis were extncted, isolated and identified. The highest level of antimicrobial activity and its yield were obtained in methanol extract. The minimum inhibition concentrations of the methanol extract were 500 $\mu\textrm{g}$mL on agar plate and 100 $\mu\textrm{g}$mL in broth media for four gram positive and four gram negative microbials. The methanol extract was fractionated by n-hexane, chloroform, ethyl ether, ethyl acetate, and butanol, orderly. The separate was developed on the TLC plate with different solvent system ratio of chloroform and methanol. Nine substances were isolated from chloroform and methanol mixture(9:1, v/v). Among them, three isolates showed antimicrobial activity. Three substances separated by HPLC were identified by GC/MS(EI) spectrum and $^1$H, /sup13/C-NMR spectrum. They were gallic acid, (-)-epicatechin and kaempferol. The antimicrobial activities of each substances were shown gallic acid, (-)-epicatechin, kaempferol orderly.

• Korean Journal of Medicinal Crop Science
• /
• v.27 no.1
• /
• pp.24-29
• /
• 2019

Background: Camellia sinensis L.(CS) is a perennial evergreen species of plant whose leaves are used to produce tea. In this plant species, the parts used are the leaves, sub-branch parts are thrown out. Methods and Results: Ethanol extract of sub-branch parts was used for isolation of major compounds by column chromatography. Structures were identified as caffeine (1), (-)-epicatechin (2) and (-)-epicatechin gallate (3) by interpretation of spectroscopic analysis, including $^1H$- and $^{13}C$-NMR. High-performance liquid chromatography (HPLC) method was used to compare the quantitative level of marker compounds in various extraction solvents of sub-branch parts of CS. The content of caffeine, (-)-epicatechin, and (-)-epicatechin gallate in 30% ethanol extract showed higher value with $3.28{\pm}0.57mg/g$, $5.53{\pm}0.88mg/g$, and $1.29{\pm}0.24mg/g$, respectively. Conclusions: These results indicated that not only leaves parts but also sub-branch, could be a good source for the functional material and pharmaceutical industry.

• Korean Journal of Pharmacognosy
• /
• v.26 no.1
• /
• pp.27-30
• /
• 1995

Tannins were isolated from the stems of Rubus coreanum and identified as (-)-epicatechin, (+)-catechin, procyanidin B-4 and sanguiin H-4 by spectral analysis.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2005.04a
• /
• pp.86-86
• /
• 2005

• Korean Journal of Pharmacognosy
• /
• v.29 no.2
• /
• pp.142-145
• /
• 1998

Two phenylpropanoids and one flavan 3-ol were isolated from Lepisorus thunbergianus (Polypodiaceae, fern), which is used as folkmedicine. Phenylpropanoids were identified as caffeic acid and chlorogenic acid, and flavan 3-ol was elucidated as (-)-epicatechin 7-O-${\beta}$-D-glucoside by physico-chemical and spectral evidences (HMQC, NOESY).

• Applied Biological Chemistry
• /
• v.44 no.1
• /
• pp.40-42
• /
• 2001

• Food Science and Biotechnology
• /
• v.15 no.5
• /
• pp.799-804
• /
• 2006

Ingestion of green tea has been shown to decrease prostaglandin $E_2$ levels in human colorectum, suggesting that tea constituents modulate arachidonic acid metabolism. In the present study, we investigated the effects of four purified green tea catechins, (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-gallate (EGCG), and (-)-epicatechin-3-gallate (ECG), on the catalytic activity of cytosolic phospholipase $A_2$ ($cPLA_2$) and release of arachidonic acid and its metabolites from intact cells. At $50\;{\mu}M$, EGCG and ECG inhibited $cPLA_2$ activity by 19 and 37%, respectively, whereas EC and EGC were less effective. The inhibitory effects of these catechins on arachidonic acid metabolism in intact cells were much more pronounced. At $10\;{\mu}M$, EGCG and ECG inhibited the release of arachidonic acid and its metabolites by 50-70% in human colon adenocarcinoma cells (HT-29) and human esophageal squamous carcinoma cells (KYSE-190 and 450). EGCG and ECG also inhibited arachidonic acid release induced by A23187, a calcium ionophore, in both HT-29 and KYSE-450 cell lines by 30-50%. The inhibitory effects of green tea catechins on $cPLA_2$ and arachidonic acid release may provide a possible mechanism for the prevention of human gastrointestinal inflammation and cancers.

• Korean Journal of Pharmacognosy
• /
• v.41 no.4
• /
• pp.245-249
• /
• 2010

As part of ongoing study focused on the discovery of natural antioxidants from Korean plants by measuring the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging effect and superoxide quenching activity, methanol extract of Cedrela sinensis (Meliaceae) was found to show potent antioxidant activities. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of four phenolic compounds, (+)-catechin (1), (-)-epicatechin (2), catechin-($4{\alpha}{\rightarrow}8$)-catechin (3) and catechin-($4{\alpha}{\rightarrow}8$)-epicatechin (4). Their structures were elucidated by spectroscopic studies. These compounds showed the significant antioxidative effects on DPPH. In riboflavin originated superoxide quenching activity, four compounds exhibited the formation of the blue formazan in a dose dependant manner.

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2004.04a
• /
• pp.296-301
• /
• 2004

We focused our research interests on the characteristic of silk fabrics dyed with green tea extracts and, moreover, revealed the catechin content of silk fabrics after dyeing with Korean tea extract by measuring the residues. Three kinds of green tea samples were taken between April and May, 2003, from Bosung(southern province in South Korea), in different terms as the first corp, the second corp, and the third corp. Before and after dyeing the silk fabrics with these extracts, catechins in the residue were analyzed by HPLC. Four kinds of Catechins, such as (-)-epicatechin(EC), (-)-epicatechin gallate(ECG), (-)-epigallocatechin (EgC), (-)-epigallocatechin gallate(EgCG) were isolated from Korean green tea extracts. Catechine contents in Korean green tea leaves depend on the making process such as heating and steaming, and the younger the richer. The absorbed catechins in sillk fabrics after dyeing followed in a decreasing order of EgCG>EgC>ECG>EC. We have found a 68% uptake of EgCG, and 116.8mg/g of EgCG in the silk fabrics after dyeing with 1% Korean green tea extracts.