• Title/Summary/Keyword: L-tyrosine

Search Result 371, Processing Time 0.025 seconds

Purification and characteristics of Lipophorin in Bombyx Mori (누에나방의 Lipophorin의 정제 및 특성)

  • Kim, Boem-Su;Kim, Hak-Ryul
    • The Korean Journal of Zoology
    • /
    • v.37 no.1
    • /
    • pp.76-87
    • /
    • 1994
  • High density lipophorin-L (HDLP-L) was purified from the hemolymph of Bombyx modi using KBr density gradient ultracentrifugation and gel permeation chromatographv (Sephadex G-2001. Lipophorin has native molecular weight of 730 Nd and consists of Apo-Lp I and Apo-Lp II with molecular weights of 250 Kd and 90 Kd, respectively. Lp contains large amounts of glutamine & glutamic acid, threonine, leucine but small amounts of cysteic acid & oxidized cystine, tyrosine, methionine. Lp also contains diacylglycerol, cholesterol, phosphatidylcholine, and phosphatidylethanolamine. Anti-lipophorin showed positive reaction with fat body and ovarial extracts and also revealed immunological identity with lipophorin of Fall webworm, Hyphantria cunea. Lipophorin maintains constant level during larval and pupal stapes but greatlv increases during adult stage in both male and female. Apo-Lp III was purified from adult hemolymph. Hemolymph was subjected to KBr ultracentrifusation and Lp-free fraction was submitted to cation exchange chromatosraphy after ammonium sulfate precipitation. Apo-Lp III has molecular weight of 17 Kd, and similar amino acid composition ar those of other species Lp but contains high amounts of tryptophan which other are tacking in.

  • PDF

Inhibitory Effects of Paeonia suffruticosa Andrews Extracts on VEGF Binding to VEGF Receptor

  • Lee, Hak-Kyo;Lee, Sung-Jin
    • Natural Product Sciences
    • /
    • v.13 no.2
    • /
    • pp.128-131
    • /
    • 2007
  • Tumor angiogenesis is a critical step f3r the growth and metastasis of solid tumors. Vascular endothelial growth factor (VEGF) is the most important angiogenic molecule associated with tumor-induced neovascularization. VEGF exerts its activity through binding to its receptor tyrosine kinase, KDR/Flk-1, expressed on the surface of endothelial cells. This study was carried out to investigate inhibitory effect of extracts from root cortex of Paeonia suffruticosa Andrews on VEGF binding to VEGF receptor. The MeOH extract from P. suffrutiocosa Andr. inhibited the binding of KDR/Flk-1-Fc to immobilized VEGF$_{165}$ more than 45% at the concentration of 100 ${\mu}$g/mL. The MeOH extract was further fractionated into n-hexane, ethyl acetate, n-BuOH, and aqueous fractions. Among the four fractions, the ethyl acetate fraction from the root cortex of P. suffruticosa Andr. exhibited highly effective inhibition (${\approx}$ 79% inhibition) and then n-BuOH fraction (${\approx}$ 45% inhibition) on the binding of KDR/Flk-1-Fc to immobilized VEGF$_{165}$ at the concentration of 100 ${\mu}$g/mL. The ethyl acetate fraction from the root cortex of P. suffruticosa Andr. more efficiently blocked VEGF-induced human umbilical vein endothelial cell proliferation, than the growth of HT1080 human fibrosarcoma. Our results suggest that P. suffruticosa Andr. may be used as a candidate fur developing anti-angiogenic agent.

A Sphingolipid and Tyrosinase Inhibitors from the Fruiting Body of Phellinus linteus

  • Kang, Hye-Sook;Park, Jin-Ho;Cho, Won-Ki;Park, Jong-Cheal;Choi, Jae-Sue
    • Archives of Pharmacal Research
    • /
    • v.27 no.7
    • /
    • pp.742-750
    • /
    • 2004
  • This paper for the first time reports the isolation of 5 compounds from Phellinus linteus. A sphingolipid (1) and two tyrosinase inhibitory compounds (2, 3) along with two carboxylic acids (4, 5), were isolated from the fruiting body of Phellinus linteus (Berk & Curt) Aoshima. The structure of compound 1 was identified as 1-O-$\beta$-D-glucopyranosyl-(2S, 3R, 4E, 8E)-2-[(2R)-2-hydroxyhexadecanoylamino]-9-methyl-4,8-octadecadiene-1,3-diol, known as cerebroside B, based on spectroscopic methods such as 1D and 2D NMR as well as by acid hydrolysis. Compounds 2-5 were identified as protocatechualdehyde (2), 5-hydroxymethyl-2-furaldehyde (HMF) (3), succinic acid (4), and fumaric acid (5) based on the spectroscopic evidence. Compounds 2 and 3 inhibited the oxidation of L-tyrosine catalyzed by mushroom tyrosinase with an $IC_{50}$ of 0.40 and 90.8 $\mu\textrm{g}$/mL, respectively. The inhibitory kinetics, which were analyzed by the Lineweaver-Burk plots, were found to be competitive and noncompetitive inhibitors with a $K_{j}$ of 1.1 $\mu\textrm{m}$ and 1.4 mM, respectively.

Changes in Bioactive Compounds and Antioxidant Capacity of Coffee under Different Roasting Conditions

  • Song, Jae Lim;Asare, Theophilus Siaw;Kang, Mi Young;Lee, Sang Chul
    • Korean Journal of Plant Resources
    • /
    • v.31 no.6
    • /
    • pp.704-713
    • /
    • 2018
  • Roasting has revealed coffee's potentials as a good source of bioactive compounds. This study was done to investigate the quantitative presence and activity of bioactive compounds including caffeine, chlorogenic acid (CGA), amino acids, and antioxidant capacity on Coffea arabica L. (Guatemala finca San Sebastian) and C. robusta L. (India Azad Hind). Analysis was performed on Green Bean (GB) Medium-Light (ML), Medium (ME) and Medium-Dark (MD) samples of both varieties. From the results, caffeine content was highest in ME samples of both varieties. GB samples of both varieties had high CGA content which decreased after increasing roasting time and temperature. Most amino acids in GB samples was highest, however, glutamic acid, valine, tyrosine, isoleucine, leucine and phenylalanine had highest quantitative increase in ME samples for both varieties. $IC_{50}$ of DPPH and ABTS radical scavenging activity was highest in ML samples of both varieties. $IC_{50}$ of reducing power and total phenolic content was highest in GB sample of both varieties but decreased after increasing roasting conditions. Generally Robusta had the highest quantity of bioactive compounds and antioxidant activity. From this study, the optimal roasting condition for coffee is ME above which there is a significant reduction of bioactive compounds and antioxidant activity.

Antimetastatic effect of fucoidan against non-small cell lung cancer by suppressing non-receptor tyrosine kinase and extracellular signal-related kinase pathway

  • Nareenath Muneerungsee;Supita Tanasawet;Wanida Sukketsiri
    • Nutrition Research and Practice
    • /
    • v.17 no.5
    • /
    • pp.844-854
    • /
    • 2023
  • BACKGROUND/OBJECTIVES: Fucoidan, a polysaccharide content in brown algae, has been reported to inhibit the growth of cancer cells. The present study aimed to investigate the suppression effects of fucoidan on A549 non-small cell lung cancer cells migration. MATERIALS/METHODS: The anti-migratory activity of fucoidan in A549 cells was examined by wound healing assay and phalloidin-rhodamine staining in response to fucoidan (0-100 ㎍/mL) treatment for 48 h. Western blot analysis was performed to clarify the protein expressions relevant to migratory activity. RESULTS: Fucoidan (25-100 ㎍/mL) significantly suppressed A549 cells migration together with reduced the intensity of phalloidin-rhodamine which detect filopodia and lamellipodia protrusions at 48 h of treatment. The protein expression indicated that fucoidan significantly suppressed the phosphorylation of focal adhesion kinase (FAK), Src, and extracellular signal-related kinase (ERK). In addition, the phosphorylation of p38 in A549 cells was found to be increased. CONCLUSIONS: Our data conclude that fucoidan exhibits anti-migratory activities against lung cancer A549 cells mediated by inhibiting ERK1/2 and FAK-Src pathway.

Current Status and Future Direction of Immunotherapy in Hepatocellular Carcinoma: What Do the Data Suggest?

  • Hye Won Lee;Kyung Joo Cho;Jun Yong Park
    • IMMUNE NETWORK
    • /
    • v.20 no.1
    • /
    • pp.11.1-11.14
    • /
    • 2020
  • Most patients with hepatocellular carcinoma (HCC) are diagnosed at an advanced stage of disease. Until recently, systemic treatment options that showed survival benefits in HCC have been limited to tyrosine kinase inhibitors, antibodies targeting oncogenic signaling pathways or VEGF receptors. The HCC tumor microenvironment is characterized by a dysfunction of the immune system through multiple mechanisms, including accumulation of various immunosuppressive factors, recruitment of regulatory T cells and myeloid-derived suppressor cells, and induction of T cell exhaustion accompanied with the interaction between immune checkpoint ligands and receptors. Immune checkpoint inhibitors (ICIs) have been interfered this interaction and have altered therapeutic landscape of multiple cancer types including HCC. In this review, we discuss the use of anti-PD-1, anti-PD-L1, and anti-CTLA-4 antibodies in the treatment of advanced HCC. However, ICIs as a single agent do not benefit a significant portion of patients. Therefore, various clinical trials are exploring possible synergistic effects of combinations of different ICIs (anti-PD-1/PD-L1 and anti-CTLA-4 antibodies) or ICIs and target agents. Combinations of ICIs with locoregional therapies may also improve therapeutic responses.

Antistress effects of Lycii Radicis Cortex in the passive avoidance test and the forced swimming test (지골피(地骨皮)가 스트레스로 인한 기억저하와 우울행동에 미치는 영향)

  • Koh, Dong-Kyun;Lee, Tae-Hee
    • The Korea Journal of Herbology
    • /
    • v.22 no.2
    • /
    • pp.137-146
    • /
    • 2007
  • Objectives : Investigation of the anitstress effects of Lycii Radicis Cortex. Methods : Behavior was measured in PAT and FST after applying stress to rats. Also, TH expression-degree in the regions of VTA and LC was measured, respectively. Results : The memory was improved in the LH 50mg/kg treated group in the passive avoidance test(P<0.01). The duration of immobility in the forced swimming test was significantly decreased in the LR 50mg/kg and 400mg/kg treated groups(P<0.0l). Stress-induced TH increases were meaningfully suppressed in the LR 100mg/kg and 400mg/kg treated group(P<0.001). Conclusion : Lycii Radicis Cortes has the effect of memory improving and antidepressant.

  • PDF

Rosmarinic Acid as a Tyrosinase Inhibitors from Salvia miltiorrhiza

  • Kang, Hye-Sook;Kim, Hyung-Rak;Byun, Dae-Seok;Park, Hye-Jin;Choi, Jae-Sue
    • Natural Product Sciences
    • /
    • v.10 no.2
    • /
    • pp.80-84
    • /
    • 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.

항진균성 항생물질을 생산하는 streptoverticillium sp. NA-4803의 분리 및 동정

  • Lim, Dae-Seog;Yoon, Sang-Kun;Lee, Myung-Sub;Yoon, Won-Ho;Kim, Chang-Han
    • Microbiology and Biotechnology Letters
    • /
    • v.24 no.6
    • /
    • pp.664-670
    • /
    • 1996
  • The aim of the present research program was to develop a strain of actinomycetes producing antifungal substance. Soil samples were collected from various sites in Korea and a number of actinomycetes were isolated from the soil samples by applying selective agar for actinomycetes. Among over 440 isolates, a strain (NA-4803) producing antifungal substance against Trichophyton spp. Nannizzia otae and Pyricularia oryzae was selected. The strain NA-4803 was identified as strain similar to Streptoverticillium blastmyceticum with respect to morphological and physiological characteristics, lecithinase and lipolytic activity, degradation of organic compounds, resistance to antibiotics and utilization of carbon and nitrogen sources. But it showed some differences such as positive reaction of nitrate reduction, negative reaction of L-tyrosine degradation, resistance to cephaloridine, and utilization of I -rhamnose and inulin. The strain NA-4803 was named as Streptoverticillium sp. NA-4803.

  • PDF

Antitumor activity of oxaliplatin, 5-FU and paclitaxel given alone and in combination with ZD1839 in human gastric carcinoma cells in vitro.

  • Jang, Ji-Hyun;Lee, Sang-Hak;Kang, Jin-Hyoung;Sun, Hee-Sik;Kuh, Hyo-Jeong
    • Proceedings of the PSK Conference
    • /
    • 2002.10a
    • /
    • pp.227.2-228
    • /
    • 2002
  • ZD1839 is a new anticancer agent which selectively inhibits EGFR tyrosine kinase. Oxaliplatin (LOHP), 5-FU (FU), and paclitaxel (PTX) have shown to be highly active against the gastric carcinomas. and ZD1839 is considered as a good candidate for the treatment of gastric cancers when combined with cytotoxic agents. In this study, we evaluated the antitumor effects of these agents in SNU-l human gastric cancer cells either alone or when given as a doublet. (omitted)

  • PDF