• Journal of the Korean Wood Science and Technology
• /
• v.38 no.2
• /
• pp.159-164
• /
• 2010

Nine compounds, caffeic acid, naringenin, apigenin, luteolin, kaempferol, verbascoside, isoverbascoside, isocampneoside II, and cistanoside F, were isolated from the EtOAc and n-BuOH fractions of P. coreana bark. The structures of these compounds (1-9) were elucidated by spectroscopic methods and literature data. All the isolates were subjected to in vitro bioassay to evaluate their inhibitory activity against rat lens aldose reductase. Among these, compounds 6 and 8 indicated the significant inhibitory activity on rat lens aldose reductase with $IC_{50}$ values of 2.67 and 5.59 ${\mu}M$, respectively. Especially, The inhibition activity of acteoside was 3.9 times better than that of quercetin as a positive control (10.6 ${\mu}M$). These results suggested that phenylethanoid glycosides are likely to be the potential compounds for the prevention and/or treatment of diabetic complications.

• Journal of Applied Biological Chemistry
• /
• v.51 no.6
• /
• pp.253-261
• /
• 2008

Isoflavone daidzein is a phytoestrogen widely distributed in Leguminosae and is especially rich in the soybean. The C6-C3 (rings B and C) unit of isoflavones is derived from the phenylpropanoid pathway and the remaining C6 (ring A) unit is from the polyketide pathway. This unique carbon skeleton is the result of isomerization of the flavone catalyzed by the isoflavone synthase, a cytochrome P450 enzyme. The isoflavones daidzein and genistein are present in the plant mostly in the glucosylated forms. However, in the human intestine, the glycosidic linkage is broken, and the free form is uptaked into blood stream. The free form is further metabolized into various reduction products to end up at the equol, which is known to have the most potent estrogenic effect among the metabolites. Several human intestinal bacteria that can convert daidzein into equol have been described, and the study into the chemistry and biochemistry of the daizein reduction would be rewarding to the improvement of the human health.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.9
• /
• pp.1429-1432
• /
• 2015

To identify plant-derived cell signaling inhibitors with antifungal properties, a twocomponent screening system using both wild-type Cryptococcus neoformans and a calcineurin mutant was employed owing to their counter-regulatory actions on the Hog1 mitogenactivated protein kinase and calcineurin pathways. Of the 2,000 plant extracts evaluated, a single bioactive compound from M. obovata Thunb. was found to act specifically on the calcineurin pathway of C. neoformans. This compound was identified as magnoloside A, and had potent antifungal activities against various Cryptococcus strains with minimum inhibitory concentration values ranging from 1.0 to 4.0 μg/ml.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.10
• /
• pp.1372-1380
• /
• 2013

Different endophytic fungi isolated from Himalayan Yew plants were tested for their ability to produce taxol. The BAPT gene (C-13 phenylpropanoid side chain-CoA acetyl transferase) involved in the taxol biosynthetic pathway was used as a molecular marker to screen taxol-producing endophytic fungi. Taxol extracted from fungal strain TBPJ-B was identified by HPLC and MS analysis. Strain TBPJ-B was identified as Fusarium redolens based on the morphology and internal transcribed spacer region of nrDNA analysis. HPLC quantification of fungal taxol showed that F. redolens was capable of producing $66{\mu}g/l$ of taxol in fermentation broth. The antitumour activity of the fungal taxol was tested by potato disc tumor induction assay using Agrobacterium tumefaciens as the tumor induction agent. The present study results showed that PCR amplification of genes involved in taxol biosynthesis is an efficient and reliable method for prescreening taxol-producing fungi. We are reporting for the first time the production of taxol by F. redolens from Taxus baccata L. subsp. wallichiana (Zucc.) Pilger. This study offers important information and a new source for the production of the important anticancer drug taxol by endophytic fungus fermentation.

• Korean Journal of Plant Resources
• /
• v.23 no.6
• /
• pp.535-540
• /
• 2010

Phenylalanine ammonia-lyase (PAL), a key enzyme of the phenylpropanoid biosynthesis pathway, is activated by a number of developmental and environmental cues. The coding region of the NtPAL4 gene was 2,154 bp in length, and its deduced protein was composed of 717 amino acids. Sequence analysis of NtPAL4 cDNA from tobacco (Nicotiana tabacum L.) revealed high structural similarity to PAL genes of other plant species. The NtPAL4 gene exists as a single copy in the tobacco plant, and its transcripts were strongly expressed in flowers and leaves. NtPAL4 expression was significantly induced in response to NaCl, mannitol, and cold treatments, but it was not induced by abscisic acid (ABA). NtPAL4 expression decreased gradually after treatment with ABA and $H_2O_2$; however, NtPAL4 transcripts accumulated after treatment with methyl viologen (MV). Our results suggest that the NtPAL4 gene may function in response to abiotic stresses.

• BMB Reports
• /
• v.31 no.1
• /
• pp.31-36
• /
• 1998

Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), the first enzyme in the phenylpropanoid biosynthesis, catalyzes the elimination reaction of ammonium ion from L-phenylalanine. PAL was purified from the cytosolic fraction of Chinese cabbage (Brassica campestris ssp. napus var. pekinensis) through ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-200 chromatography, and Q-Sepharose chromatography. It consists of four identical subunits, the molecular mass of which was estimated to be about 38,000 daltons on SDS-PAGE. The optimal pH and temperature of the purified enzyme are 8~9 and $45^{\circ}C$, respectively. Its activity is greatly inhibited by $Zn^{2+}$ ion, and strongly activated by caffeic acid. The purified PAL has some different characteristics compared to those obtained with other PALs.

• Biomolecules & Therapeutics
• /
• v.22 no.1
• /
• pp.62-67
• /
• 2014

This study was designed to find some potential natural products and/or constituents inhibiting proinflammatory cytokine generation in lung inflammation, since cytokines such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interleukin-6 (IL-6) are pivotal for provoking airway inflammation. In our preliminary screening procedure, the 70% ethanol extract of the leaves of Perilla frutescens (PFE) was found to clearly inhibit TNF-${\alpha}$ production in the lung at 100 mg/kg, after intranasal lipopolysaccharide treatment of mice. Based on this result, ten constituents including phenylpropanoids (allyltetramethoxybenzene, caffeic acid, dillapiole, elemicin, myristicin, nothoapiole, rosmarinic acid methyl ester, rosmarinic acid) and monoterpenes (perilla aldehyde and perilla ketone) were successfully isolated from the extract. Among them, elemicin and myristicin were found for the first time to concentration-dependently inhibit IL-$1{\beta}$-treated IL-6 production from lung alveolar epithelial cells (A549) at concentrations of $10-100{\mu}M$. These findings suggest that the phenylpropanoids including elemicin and myristicin have the potential to be new inhibitory agents against lung inflammation and they may contribute, at least in part, to the inhibitory activity of PFE on the lung inflammatory response.

• Korean Journal of Veterinary Research
• /
• v.39 no.2
• /
• pp.287-293
• /
• 1999

Isoeugenol, one of the phenylpropanoid derivatives has been known to inhibit the lipid peroxidation via scavenging effect on hydroxyl or superoxide radical production. We examined whether isoeugenol has a inhibitory effect against N-methyl-D-aspartate(NMDA)-, oxygen/glucose deprivation- and xanthine/xanthine oxidase(X/XO)-induced neurotoxicity or NMDA-induced $^{45}Ca^{+2}$ uptake elevation in primary mouse vertical cultures. We also evaluated whether isoeugenol exhibits inhibitory action on NMDA-induced convulsion in mice. Isoeugenol ($30{\sim}300{\mu}M$) attenuated NMDA- and X/XO-induced neurotoxicity by 11~85% and 83~92%, respectively. In the oxyge/glucose deprivation(60 min)-induced neurotoxicity, isoeugenol significantly(p<0.05) reduced by 32% at the maximal concentration. However, it failed to ameliorate NMDA-induced $^{45}Ca^{+2}$ uptake elevation. Isoeugenol(0.5g/kg, i.p.) delayed 6.5 times on the onset time of convulsion evoked by NMDA($0.1{\mu}g$) compared to that of control. These results suggest that the neuroprotective action of isoeugenol may be ascribed to the modulation of massive generation of reactive oxygen species(ROS) occurred during the ischemic or excitotoxic damage, not by directly affecting the NMDA receptor.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.1
• /
• pp.117-122
• /
• 2014

As a Chinese herbal medicine used in East Asia for thousands years, Cortex Magnoliae Officinalis (CMO) was observed to possess a protective effect against OH-induced DNA damage in the study. To explore the mechanism, the antioxidant effects and chemical contents of five CMO extracts were determined by various methods. On the basis of mechanistic analysis, and correlation analysis between antioxidant effects & chemical contents, it can be concluded that CMO exhibits a protective effect against OH-induced DNA damage, and the effect can be attributed to the existence of phenolic compounds, especially magnolol and honokiol. They exert the protective effect via antioxidant mechanism which may be mediated via hydrogen atom transfer (HAT) and/or sequential electron proton transfer (SEPT). In the process, the phenolic-OH moiety in phenylpropanoids is oxidized to the stable quinine-like form and the stability of quinine-like can be ultimately responsible for the antioxidant.

• Archives of Pharmacal Research
• /
• v.27 no.6
• /
• pp.615-618
• /
• 2004

In the course of screening for reactive oxygen species scavengers from natural products, an antioxidant was isolated from the mycelial culture broth of Phellinus linteus and identified as hispidin. The hispidin content was reached its maximum level at 12 days after onset of inoculation. About 2.5 mg／mL of hispidin was produced by P linteus in a yeast-malt medium (pH 5.8, $25^{\circ}C$). Hispidin inhibited 22.6 and 56.8% of the super oxide anion radical, 79.4 and 95.3% of the hydroxyl radical, and 28.1 and 85.5% of the DPPH radical at 0.1 and 1.0 mM, respectively. The positive control ${\alpha}-tocopherol$ scavenged 25.6 and 60.3%, 74.6 and 96.3%, and 32.7 and 77.5% of each radical, respectively, at the same concentrations. However, hispidin showed no significant activity on the hydrogen peroxide radical.