• The Korean Journal of Food And Nutrition
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• v.34 no.5
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• pp.553-559
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• 2021

The aim of study to investigate the phytochemicals and biological activities the bark of Betula schmidtii. The studies consisted of the solvent extraction, followed by the isolation of phenolic components 1~3 from ethyl acetate-soluble fraction of Betula schmidtii Bark. Their chemical structures were identified as arbutin (1), ρ-coumaric acid (2) and ferulic acid (3) using Ultraviolet-Visible (UV-Vis) Spectrophotometer, Electrospray Ionization Mass Spectrometry (ESI-MS) (negative ion mode), ¹H-Nuclear Magnetic Resonance (NMR), ¹³C-NMR, ¹H-¹H Correlation Spectroscopy (COSY) and ¹H-¹³C Hetero Nuclear Multiple Quantum Correlation (HMQC) spectral data. Compounds 1~3 shows the anti-oxidant effect with IC₅₀ values of 29.74±1.52, 21.32±1.07 and 34.41±1.24 in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, respectively. Also, compounds 1~3 exhibited mushroom tyrosinase inhibitory activity with IC₅₀ values of 31.14±1.07, 42.54±1.46 and 69.22±1.43 µM, respectively.

• Natural Product Sciences
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• v.25 no.2
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• pp.122-129
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• 2019

The roots of Phlomis umbrosa (Turcz.) (Phlomidis Radix) have been traditionally used to treat cold, reduce swelling and staunch bleeding. Four iridoids (1 - 3 and 5) and six phenylethanoid derivatives (4, and 6 - 10) were isolated from the roots of P. umbrosa. A simple, sensitive, and reliable analytical HPLC/PDA method was developed, validated, and applied to determine 10 marker compounds in Phlomidis Radix. Furthermore, the isolates were evaluated for cytotoxic and anti-oxidant activities as well as DPPH-HPLC method. Among them, compounds 4 and 6 - 9 displayed potent anti-oxidant capacities using DPPH assay with $IC_{50}$ values of $27.7{\pm}2.4$, $10.2{\pm}1.1$, $18.0{\pm}0.8$, $19.1{\pm}0.3$, and $19.9{\pm}0.6{\mu}M$, and compounds 6, 8, and 9 displayed significant cytotoxic activity against HL-60 with $IC_{50}$ values of $35.4{\pm}3.1$, $18.6{\pm}2.0$, and $42.9{\pm}3.0{\mu}M$, respectively.

• Archives of Pharmacal Research
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• v.26 no.7
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• pp.535-539
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• 2003

The EtOAc soluble fraction from the stem of Sorghum bicolor showed a strong free radical scavenging activity. Five major compounds were isolated from this fraction. They were identified by spectral data as methyl ferulate (1), methyl p-hydroxycinnamate (2), p-hydroxybenzaldehyde (3), tricin (4), and quercetin 3,4 -dimethyl ether (5). Among these compounds, 1 exhibited a strong, free radical scavenging activity on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) with an $IC_50$ value of 0.7 $\mu$M. We further studied the effects of these isolated compounds on the lipid peroxidation in rat liver microsomes induced by non-enzymatic method. All five compounds showed anti-lipid peroxidation activity ($IC_50$ values of 0.5, 0.4, 0.3 and 0.3 $\mu$ M, respectively).

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.1169-1172
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• 2004

The cytotoxic activity of 13(E)-labd-13-ene-8α, 15-diol (1) was evaluated against tumor cell lines. A comparison of IC/sub 50/ values of this compound in cancer cell lines showed that their susceptibility to this compound decreased in the following order: P388>B16{F10>MDA-MB-231>A549>KB>SNU-C4 by the MTT method. 13(E}-Labd-13-ene-8α, 15-diol (1) was the most effective growth inhibitor of P388 murine leukaemia cell lines, producing approximately 8.3㎍/mL of IC/sub 50/ in the MTT method.

• Natural Product Sciences
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• v.10 no.2
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• pp.80-84
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• 2004

Rosmarinic acid and its methyl ester, isolated from the ethyl acetate soluble fraction of the methanolic extract of Salvia miltiorrhiza Bunge (Labiatae), were found to inhibit the oxidation of L-tyrosine catalyzed by mushroom tyrosinase with the $IC_{50}$ values of 16.8 and $21.5\;{\mu}M$, respectively. It was comparable with kojic acid, a well-known tyrosinase inhibitor, with an $IC_{50}$ of $22.4\;{\mu}M$. The inhibitory kinetics analyzed by the Lineweaver-Burk plots, were found rosmarinic acid and its methyl ester to be competitive inhibitors with $K_i\;of\;2.4{\times}10^{-5}\;and\;1.5{\times}10^{-5}\;M$, respectively.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.262.2-263
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• 2003

Two phenylbutenoids, 4-(3',4'-dimethoxyphenyl)buta-1,3-diene (1) and 4-(2',4',5'-trimethoxyphenyl)buta-1,3-diene (2), were isolated from the roots of Zingiber cassumunar Roxb. (Zingiberaceae), as active constituents by bioassay-guided fractionation using a cytotoxicity assay against the HT1080 (human fibrosarcoma) cells. The isolates 1 and 2 exhibited a significant cytotoxicity with IC$\sub$50/ values of 0.71 and 0.74$\mu\textrm{g}$/$m\ell$, respectively, which are comparative to the positive control ellipticine (IC$\sub$50/=1.1 $\mu\textrm{g}$/ml). (omitted)

• Natural Product Sciences
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• v.15 no.2
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• pp.110-113
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• 2009

Acyl-coenzyme A: cholesterol acyltransferase (ACAT) catalyzes cholesterol esterification and plays important roles in intestinal absorption of cholesterol, hepatic production of lipoproteins and accumulation of cholesteryl ester within macrophages and smooth muscle cells. In our study, eight polyacetylenes (1 - 8), were isolated from the roots of Gymnaster koraiensis, and their chemical structures were identified on the basis of spectroscopic analysis and mass. Compound 2 with the (10S)-15,16-epoxy group in skeleton strongly inhibited ACAT enzyme with $IC_{50}$ value of 35.8 ${\mu}g$/mL, meanwhile the other compounds displayed significant inhibition of ACAT enzyme with the $IC_{50}$ values from 45.5 to 55.1 ${\mu}g$/mL.

• Nutrition Research and Practice
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• v.1 no.3
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• pp.189-194
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• 2007

This study investigated in vitro antioxidant activity of Sonchus oleraceus L. by extraction solvent, which were examined by reducing power, hydroxyl radical-scavenging activity(HRSA) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assays. 70% MeOH extract had the greatest reducing power while EtOH extract had the greatest HRSA. The antioxidant activity of S. oleraceus extracts was concentration dependent and its $IC_{50}$ values ranged from 47.1 to $210.5\;{\mu}g/ml$ and $IC_{50}$ of 70% MeOH, boiling water and 70% EtOH extracts were 47.1, 52.7 and $56.5\;{\mu}g/ml$, respectively. 70% MeOH extract of S. oleraceus contained the greatest amount of both phenolic and flavonoid contents. The extracts tested had greater nitrite scavenging effects at lower pH conditions. The cytotoxic activity showed that EtOH extract had the best activity against the growth of stomach cancer cell. These results suggest that S. oleraceus extract could be used as a potential source of natural antioxidants.

• Journal of Pharmaceutical Investigation
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• v.25 no.4
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• pp.365-369
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• 1995

The acute cytotoxicities of chloroquine sulfate, propranolol, ascorbic acid, acetylsalicylic acid and acrylamide on cultured adult rat hepatocytes were evaluated by the use of LDH leakage and NR uptake test. On the basis of $IC_{50}$ values, the rank order of cytotoxicities of these drugs in both tests was chloroquine sulfate > propranolol > acetylsalicylic acid > ascorbic acid. The $IC_{50}$ of LDH test was very similar to that of NR uptake test. Thus, we concluded that both tests are reliable and sensitive methods in detecting toxicity in adult cultured rat hepatocytes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.751-755
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• 1998

Functional properties of yam mucilage were investigated by physicochemical analysis. Yam mucilage was extracted from the root of yam and then separated into two fractions by its selective aggregation with isopropanol concentration. Each mucilge fraction showed the excellent binding properties with heavy metal ions Co, Cr and Cu. Cr showed the higher affinity with mucilage than Co and Cu at pH 6.3. In ACE inhibition, IC50 values of mucilage fraction 1 and 2 showed 8.99$\mu\textrm{g}$/${mu}ell$ and 7.1$\mu\textrm{g}$/${mu}ell$, respectively.