• Korean Journal of Medicinal Crop Science
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• 제14권5호
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• pp.267-272
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• 2006

Phytochemical study on the EtOAc fraction from the MeOH extract of the leaves of Cedrela sinensis led to the isolation of five known phenolic compounds (1-5), whose structures were identified as (+)-catechin (1), $kaempferol-3-0-{\alpha}- L-rhamnopyranoside$ (2), quercetin (3), $quercetin-3-O-{\alpha}-L-rhamnopyranoside$ (4), and $quercetin-3-O-{\beta}-D-glucopyranoside$ (5), respectively, by comparing their spectral $(uv,\;JR,\;IH\;and\;^{13}C-NMR,\;and\;ESI-MS)$ and physicochemical data with those reported in the literature. Among the isolated compounds (1-5), compounds 1 and 3-5 exhibited significant DPPH radical scavenging effects with $IC{_50}$ values ranging from $21.3{\pm}1.4\;to\;38.1{\pm}3.2 {\mu}M$ as well as superoxide anion radical scavenging effects with $IC{_50}$ values ranging from $9.4{\pm}0.7\;to\;21.2{\pm}3.6 {\mu}M$. Furthermore, compounds 1 and 3-5 also exhibited considerable inhibitory effects on LDL peroxidation induced by either $CU^{2+}$ or AAPH with $IC{_50}$ values ranging from $1.4{\pm}0.4\;to\;11.9{\pm}1.4\;{\mu}M$. These results indicated that flavonoids are the major constituents of C. sinensis and considered to be antioxidant principles of this plant.

• Journal of Food Hygiene and Safety
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• 제15권2호
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• pp.167-172
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• 2000

Lithospermum erythrorhyzon has been used as a red fooddye and traditional Chinese medicine to treat wounds, skin diseases and burns. Platelet activation plays an important role in thrombosis and haemostasis. Here, we studied the inhibition of platelet activation and its active compound from the root of Lithospermum erythrorhyzon. Its ethyl acetate extract inhibited the aggregation of washed rabbit platelets induced by collagen or thrombin. Five naphthoquinone pigments , shikonin , acetylshikonin , is obutylshikonin, $\alpha$-methyl-n-butylshikonin and $\beta$,$\beta$-dimethylacrylshikonin were isolated by means of high pressure liquid chromatography. The structures were determined by comparison of their proton nuclear magnetic resonance spectra. The potency of their inhibition was in the following order : $\beta$,$\beta$-dimethylacrylshikonin$\geq$$\alpha$-methyl-n-butylshikonin>isobutylshikonin>acetylshikonin>shikonin. It is suggested that the size of the aliphatic hydroxy group of shikonin is important for the enhancement of potency.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• 제16권1호
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• pp.94-99
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• 2003

Objectives : Gram-positive bacteria have became increasing resistant to antibacterial agents, and hence multi-drug-resistant bacterial pathogens are now a major problem in clinical medicine. There is, therefore, a need for new antibacterial agents. In the course of our screening program for potent antibacterial agent from medicinal plants, the extract of Salvia miltiorrhiza (S. miltiorrhiza) showed antibacterial activity against methcillin resistant Staphylococcus aureus (MRSA) and antibiotic-resistant S. aureus. Methods : S. miltiorrhiza was extracted with 80$\%$ EtOH. The extract was suspended in H2O and fractionated successively with hexane chloroform, ethyl acetate, and n-buthanol. The chloroform fraction, which showed the highest antibacterial activity(MICs, 78㎍/ml) against MRSA, was chromatographed on a silica gel column and recycling prep-LC to give the pure antibacterial component. Results and Conclusions : The second fraction among the chloroform soluble portion of an aqueous EtOH extract of S. miltiorrhiza root showed outstanding antibacterial activity against MRSA and antibiotic-resistant S. aureus compared to the other fraction. An active compound was isolated from the second fraction using silica gel column chromatoraphy and recycling prep-LC. Based on these data together with the IH-, 13C-NMR, mass and mp, the active compounds were identified tanshinone Ⅰ, dehydrotanshinone Ⅰ and cryptotanshinone. Among tanshinones, cryptotanshinone and dihydrotanshinone Ⅰ MICs against MRSA and antibiotics-resistant S. aureus were 12.5, 12.5 and 6.3㎍/ml, respectively.

• BMB Reports
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• 제31권6호
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• pp.595-599
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• 1998

To investigate conformational information of a low oxygen affinity recombinant hemoglobin (rHb) containing $96Val{\rightarrow}Trp$ mutation at the ${\alpha}96$ position, we ave produced rHb (${\alpha}96Val{\rightarrow}Phe$) and rHb (${\alpha}96Val{\rightarrow}Tyr$), using the Escherichia coli expression system and site-directed mutagenesis. The oxygen affinity of rHb (${\alpha}96Val{\rightarrow}Phe$) is similar to that of human normal adult hemoglobin (Hb A). However, the oxygen affinity of rHb (${\alpha}96Val{\rightarrow}Tyr$) showed much lower oxygen affinity than Hb A which is similar to that of rHb (${\alpha}96Val{\rightarrow}Tyr$), providing an opportunity as a potential candidate for a hemoglobin-based blood substitute. Both rHb (${\alpha}96Val{\rightarrow}Phe$) and rHb (${\alpha}96Val{\rightarrow}Tyr)$ showed high cooperativity in oxygen binding. IH-NMR spectroscopy shows that both rHb (${\alpha}96Val{\rightarrow}Phe$) and rHb (${\alpha}96Val{\rightarrow}Tyr$) have very similar tertiary structure around the heme pockets and uaternary structure in the ${\alpha}_1/{\beta}_2$ subunit interface ompared to Hb A. The low oxygen affinity of rHb (${\alpha}96Val{\rightarrow}Tyr$) has been suggested to be due to a hydrogen bond caused by an extra hydroxyl group not present in rHb (${\alpha}96Val{\rightarrow}Phe$). However, investigation of the carbonmonoxy form of rHb (${\alpha}96Val{\rightarrow}Phe$) and (${\alpha}96Val{\rightarrow}Try$) in the presence of inositol hexaphosphate at low temperature suggests that low oxygen affinity of (${\alpha}96Val{\rightarrow}Try$) may arise from a mechanism different to that of rHb (${\alpha}96Val{\rightarrow}Trp$).

• Korean Journal of Food Science and Technology
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• 제31권6호
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• pp.1667-1678
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• 1999

Certain parts of 190 kinds of medicinal herbs and 171 kinds of original materials of food were extracted by methanol. The extracts were tested their microbial inhibition activities against several food spoilage microorganisms, Micrococcus luteus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, Escherichia coli, Saccharomyces cerevisiae, Candida albicans, Penicillium citrinum, Aspergillus flavus and Aspergillus niger. The methanol extracts of Cornus officinalis, Evodia officinalis, Glycyrrhiza glabra, Salvia miltiorrhiza. Schizandrae fructus, Coptidis rhizoma, aroma hop and bitter hop were shown inhibitory effect on certain species of gram(+) bacteria. Aroma hop and bitter hop were shown inhibitory effect on certain species of gram(-) bacteria. The methanol extract of Salvia miltiorrhiza exhibited a strong antibacterial activities. It was purified by solvent fractionation, silicagel column chromatography, prep. TLC, prep. HPLC. The purified active substance was identified as cryptotanshinone by EIMS, $1^H-NMR,\;{13}^C-NMR$ and DEPT. Cryptotanshinone showed a strong antibacterial activity against gram positive bacteria $(MIC\;:\;3.91{\sim}62.50\;{\mu}g/mL)$. Especially, this compound was the most strong activity against Bacillus subtilis $(MIC\;:\;3.91\;{\mu}g/mL)$.

• Analytical Science and Technology
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• 제13권4호
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• pp.494-503
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• 2000

A 21-residue peptide corresponding to amino acids 84-104 of $p16^{INK4A}$, the tumor suppressor, has been synthesized and its structure was studied by Circular Dichroism, $^1H$ NMR spectroscopy and molecular modeling. A p16-derived peptide (84-104 amino acids) forming stable complex with CDK4 and CDK6 inhibits the ability of CDK4/6 to phosphorylate pRb in vitro, and blocks cell-cycle progression through G1/S phase as shown in the function of the full-length p16. Its NMR spectral data including NOEs, $^3J_{NH-H{\alpha}}$ coupling constants, $C_{\alpha}H$ chemical shift, the average amplitude of amide chemical shift oscillation and temperature coefficients indicate that the secondary structure of a p16-derived peptide is similar to that of the same region of full-length p16, which consists of helix-turn-helix structure. The 3-D distance geometry structure based on NOE-hased distance and torsion angle restraints is characterized by ${\gamma}$-turn conformation between residues $Gly^{89}-Leu^{91}$(${\varphi}_{i+1}=-79.8^{\circ}$, ${\varphi}_{i+1}=60.2^{\circ}$) as evidenced in a single crystal structure for the corresponding region of p18 or p19, but is undefined at both the N and C termini. This compact and rigid ${\gamma}$-turn region is considered to stabilize the structure of p16-derived peptide and serve as a site recognizing cyelin dependent kinase, and this well-defined ${\gamma}$-turn structure could be utilized for the design of anti-cancer drug candidates.