DOCSLIB.ORG

Identification and Characterization of Phlorizin Transporter from Arabidopsis 2 Thaliana and Its Application for Phlorizin Production in Saccharomyces Cerevisiae

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Identification and Characterization of Phlorizin Transporter from Arabidopsis 2 Thaliana and Its Application for Phlorizin Production in Saccharomyces Cerevisiae bioRxiv preprint doi: https://doi.org/10.1101/2020.08.14.248047; this version posted August 14, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Identification and characterization of phlorizin transporter from Arabidopsis 2 thaliana and its application for phlorizin production in Saccharomyces cerevisiae 3 Zeinu Mussa Belew1, Christoph Crocoll1, Iben Møller-Hansen2, Michael Naesby3, Irina Borodina2, Hussam 4 Hassan Nour-Eldin1* 5 6 1DynaMo Center, Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, 7 University of Copenhagen, 1871 Frederiksberg, Denmark 8 2The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet 220, 9 2800 Kongens Lyngby, Denmark 10 3 Evolva SA, Duggingerstrasse 23, 4153 Reinach, Switzerland 11 12 *Corresponding author: Hussam H. Nour-Eldin ([email protected]) 13 14 15 16 17 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.08.14.248047; this version posted August 14, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 18 Abstract 19 Bioengineering aimed at producing complex and valuable plant specialized metabolites in microbial hosts 20 requires efficient uptake of precursor molecules and export of final products to alleviate toxicity and 21 feedback inhibition. Plant genomes encode a vast repository of transporters of specialized metabolites that— 22 due to lack of molecular knowledge—remains largely unexplored in bioengineering. Using phlorizin as a case 23 study—an anti-diabetic and anti-cancerous flavonoid from apple—we demonstrate that brute-force 24 functional screening of plant transporter libraries in Xenopus oocytes is a viable approach to identify 25 transporters for bioengineering. By screening 600 Arabidopsis transporters, we identified and characterized 26 purine permease 8 (AtPUP8) as a bidirectional phlorizin transporter. Functional expression in the plasma 27 membrane of a phlorizin-producing yeast strain increased phlorizin titer by more than 80 %. This study 28 provides a generic approach for identifying plant exporters of specialized metabolites and demonstrates the 29 potential of transport-engineering for improving yield in bioengineering approaches. 30 31 32 33 34 35 36 Keywords 37 Phlorizin transporter, transport-engineering, Saccharomyces cerevisiae, purine permease family (PUP), 38 Xenopus laevis oocytes 39 40 Abbreviations 41 UGT, UDP-dependent-glycosyltransferase; HRT, homologous recombination tag; OD600, optical density at 600 42 nm; LC-MS, liquid chromatography mass spectrometry 2 bioRxiv preprint doi: https://doi.org/10.1101/2020.08.14.248047; this version posted August 14, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 43 1. Introduction 44 Plants synthesize a vast number of specialized small molecules that have pharmaceutical and nutraceutical 45 values. These molecules are usually produced in minute amounts in the natural plant host, wherefrom 46 extraction may be costly, insufficient and time-consuming (Liu et al., 2017; Lv et al., 2016). As a promising 47 alternative, bioengineering in microorganisms such as Saccharomyces cerevisiae and Escherichia coli has 48 emerged as a sustainable and cost-effective means for large-scale production of high-value plant natural 49 products (Keasling, 2012; Krivoruchko and Nielsen, 2015; Suzuki et al., 2014). 50 For any bioengineering approach, transport proteins play critical roles in uptake of nutrients, cofactors and 51 precursors and also for secretion of final products to alleviate toxicity and feedback inhibition that may 52 hamper yield (Jones et al., 2015; Lee et al., 2012; Liu et al., 2017; Shu and Liao, 2002). 53 Transporters native to the producing microbial cell factory (endogenous transporters) or heterologous 54 transporters obtained from other organisms can be utilized in transport-engineering approaches aimed at 55 improving these transport processes. Most studies implementing transport-engineering have so far targeted 56 microbial transporters. For example, tolerance of E. coli was improved by applying directed evolution to 57 enhance the export efficiency of AcrB towards toxic biofuels and plastic precursors (Fisher et al., 2014; Foo 58 and Leong, 2013). In other examples, overexpression of YddG, MsbA and YadH improved secretion and 59 thereby production of various amino acids, biofuels and plant natural products such as anthocyanins in E. coli 60 (Doroshenko et al., 2007; Doshi et al., 2013; Lim et al., 2015). 61 Given the enormous diversity of chemical structures in plant specialized metabolism, the field of transport- 62 engineering will require access to a large repository of transporters. The general participation of separate 63 organs and/or cells in the synthesis and accumulation of plant specialized metabolites indicates that plant 64 genomes encode a plethora of specialized metabolite transporters (Shitan, 2016; Yazaki, 2005). However, in 65 the context of bioengineering, plant transporters remain largely unexplored. 66 In this study, we seek to address two challenges; i) how to identify plant transporters relevant for a given 67 bioengineering approach and ii) demonstrating the potential of using plant transporters to improve 68 production in a given bioengineering approach. 69 As a case study, we focus on phlorizin, a dihydrochalcone O-glucoside predominantly found in apple (Malus 70 sp.), which is comprised of a glucose moiety and two aromatic rings joined by an alkyl spacer. Phlorizin is 71 medicinally important as it decreases blood glucose levels, has been used as both a remedy and a tool to 72 study renal physiology for nearly two centuries and has been used as a blueprint to develop several 3 bioRxiv preprint doi: https://doi.org/10.1101/2020.08.14.248047; this version posted August 14, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 73 commercialized anti-diabetic drugs (Ehrenkranz et al., 2005; Kramer and Zinman, 2019; Meng et al., 2008; 74 Nomura et al., 2010; Scheen, 2015). 75 Recently, a pathway consisting of seven enzymes was engineered into S. cerevisiae for de novo production of 76 phlorizin (Eichenberger et al., 2017). The titer is low for industrial production indicating that optimization of 77 the biosynthesis pathway is possible, for example by increasing cytoplasmic malonyl-CoA, altering gene copy 78 number, enzyme origins, and culture conditions (Galanie and Smolke, 2015; Li et al., 2015; Rodriguez et al., 79 2015). Although precursor supply (such as malonyl-CoA, a ) is a major bottleneck for microbial production of 80 flavonoids in general and phlorizin in particular (Delmulle et al., 2018; Eichenberger et al., 2017), product 81 toxicity, negative feedback inhibition by intermediates (such as cinnamic acid and p-coumaric acid) on early 82 biosynthetic enzymes (Blount et al., 2000; Lam et al., 2008; Sarma and Sharma, 1999) and by-product UDP 83 inhibition on the last biosynthetic enzyme UGT (Zhang et al., 2016) could hamper overall flux into the 84 phlorizin pathway. 85 Phlorizin is a polar compound that requires a membrane-bound transporter protein to traverse membranes. 86 In this study, we explore whether titer can be increased by expressing an efficient phlorizin exporter to 87 improve product secretion from the phlorizin producing yeast strain. To test this hypothesis, we faced a 88 typical knowledge gap in plant specialized metabolism, which is that as of date, no phlorizin transporters 89 have been identified. 90 We have developed a functional genomics approach wherein we build and functionally screen sequence- 91 indexed full-length transporter cDNA libraries in Xenopus oocytes for activity towards target compounds 92 (Nour-Eldin et al., 2006). Here, we screen a library consisting of 600 transporters from Arabidopsis and 93 identify the first reported phlorizin transporter. Extensive biophysical characterization in Xenopus oocytes 94 reveals a passive, medium-affinity, proton gradient-independent, bidirectional transport activity, which 95 when introduced into a phlorizin producing yeast strain increased titer significantly. The transporter belongs 96 to the purine permease family (PUP) present in all plants, which here has its substrate spectrum expanded 97 to include a novel class of specialized metabolites. This study provides a generic approach for identifying 98 plant exporters of specialized metabolites and demonstrates the potential of transport-engineering for 99 improving yield in bioengineering of plant specialized metabolites. 4 bioRxiv preprint doi: https://doi.org/10.1101/2020.08.14.248047; this version posted August 14, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is
Load more

Recommended publications
  • Role of Apple Phytochemicals, Phloretin and Phloridzin, in Modulating Processes Related to Intestinal Inflammation
    nutrients Article Role of Apple Phytochemicals, Phloretin and Phloridzin, in Modulating Processes Related to Intestinal Inflammation Danuta Zielinska 1, José Moisés Laparra-Llopis 2, Henryk Zielinski 3, Dorota Szawara-Nowak 3 and Juan Antonio Giménez-Bastida 3,4,* 1 Department of Chemistry, University of Warmia and Mazury, 10-727 Olsztyn, Poland; [email protected] 2 Group of Molecular Immunonutrition in Cancer, Madrid Institute for Advanced Studies in Food (IMDEA-Food), 28049 Madrid, Spain; [email protected] 3 Institute of Animal Reproduction and Food Research, Department of Chemistry and Biodynamics of Food, Polish Academy of Science, 10-748 Olsztyn, Poland; [email protected] (H.Z.); [email protected] (D.S.-N.) 4 Group on Quality, Safety and Bioactivity of Plant Foods, Centro de Edafología y Biología Aplicada del Segura (CSIC), 30100 Murcia, Spain * Correspondence: [email protected] Received: 25 April 2019; Accepted: 23 May 2019; Published: 25 May 2019 Abstract: Plant-derived food consumption has gained attention as potential intervention for the improvement of intestinal inflammatory diseases. Apple consumption has been shown to be effective at ameliorating intestinal inflammation symptoms. These beneficial effects have been related to (poly)phenols, including phloretin (Phlor) and its glycoside named phloridzin (Phldz). To deepen the modulatory effects of these molecules we studied: i) their influence on the synthesis of proinflammatory molecules (PGE2, IL-8, IL-6, MCP-1, and ICAM-1) in IL-1β-treated myofibroblasts of the colon CCD-18Co cell line, and ii) the inhibitory potential of the formation of advanced glycation end products (AGEs).
    [Show full text]
  • Natural Products As Lead Compounds for Sodium Glucose Cotransporter (SGLT) Inhibitors
    Reviews Natural Products as Lead Compounds for Sodium Glucose Cotransporter (SGLT) Inhibitors Author ABSTRACT Wolfgang Blaschek Glucose homeostasis is maintained by antagonistic hormones such as insulin and glucagon as well as by regulation of glu- Affiliation cose absorption, gluconeogenesis, biosynthesis and mobiliza- Formerly: Institute of Pharmacy, Department of Pharmaceu- tion of glycogen, glucose consumption in all tissues and glo- tical Biology, Christian-Albrechts-University of Kiel, Kiel, merular filtration, and reabsorption of glucose in the kidneys. Germany Glucose enters or leaves cells mainly with the help of two membrane integrated transporters belonging either to the Key words family of facilitative glucose transporters (GLUTs) or to the Malus domestica, Rosaceae, Phlorizin, flavonoids, family of sodium glucose cotransporters (SGLTs). The intesti- ‑ SGLT inhibitors, gliflozins, diabetes nal glucose absorption by endothelial cells is managed by SGLT1, the transfer from them to the blood by GLUT2. In the received February 9, 2017 kidney SGLT2 and SGLT1 are responsible for reabsorption of revised March 3, 2017 filtered glucose from the primary urine, and GLUT2 and accepted March 6, 2017 GLUT1 enable the transport of glucose from epithelial cells Bibliography back into the blood stream. DOI http://dx.doi.org/10.1055/s-0043-106050 The flavonoid phlorizin was isolated from the bark of apple Published online April 10, 2017 | Planta Med 2017; 83: 985– trees and shown to cause glucosuria. Phlorizin is an inhibitor 993 © Georg Thieme Verlag KG Stuttgart · New York | of SGLT1 and SGLT2. With phlorizin as lead compound, specif- ISSN 0032‑0943 ic inhibitors of SGLT2 were developed in the last decade and some of them have been approved for treatment mainly of Correspondence type 2 diabetes.
    [Show full text]
  • Myricetin Antagonizes Semen-Derived Enhancer of Viral Infection (SEVI
    Ren et al. Retrovirology (2018) 15:49 https://doi.org/10.1186/s12977-018-0432-3 Retrovirology RESEARCH Open Access Myricetin antagonizes semen‑derived enhancer of viral infection (SEVI) formation and infuences its infection‑enhancing activity Ruxia Ren1,2†, Shuwen Yin1†, Baolong Lai2, Lingzhen Ma1, Jiayong Wen1, Xuanxuan Zhang1, Fangyuan Lai1, Shuwen Liu1* and Lin Li1* Abstract Background: Semen is a critical vector for human immunodefciency virus (HIV) sexual transmission and harbors seminal amyloid fbrils that can markedly enhance HIV infection. Semen-derived enhancer of viral infection (SEVI) is one of the best-characterized seminal amyloid fbrils. Due to their highly cationic properties, SEVI fbrils can capture HIV virions, increase viral attachment to target cells, and augment viral fusion. Some studies have reported that myri- cetin antagonizes amyloid β-protein (Aβ) formation; myricetin also displays strong anti-HIV activity in vitro. Results: Here, we report that myricetin inhibits the formation of SEVI fbrils by binding to the amyloidogenic region of the SEVI precursor peptide (PAP248–286) and disrupting PAP248–286 oligomerization. In addition, myricetin was found to remodel preformed SEVI fbrils and to infuence the activity of SEVI in promoting HIV-1 infection. Moreover, myricetin showed synergistic efects against HIV-1 infection in combination with other antiretroviral drugs in semen. Conclusions: Incorporation of myricetin into a combination bifunctional microbicide with both anti-SEVI and anti- HIV activities is a highly promising approach to preventing sexual transmission of HIV. Keywords: HIV, Myricetin, Amyloid fbrils, SEVI, Synergistic antiviral efects Background in vivo because they facilitate virus attachment and inter- Since the frst cases of acquired immune defciency nalization into cells [4].
    [Show full text]
  • The Na+/Glucose Co-Transporter Inhibitor Canagliflozin Activates AMP-Activated Protein Kinase by Inhibiting Mitochondrial Function and Increasing Cellular AMP Levels
    Page 1 of 37 Diabetes Hawley et al Canagliflozin activates AMPK 1 The Na+/glucose co-transporter inhibitor canagliflozin activates AMP-activated protein kinase by inhibiting mitochondrial function and increasing cellular AMP levels Simon A. Hawley1†, Rebecca J. Ford2†, Brennan K. Smith2, Graeme J. Gowans1, Sarah J. Mancini3, Ryan D. Pitt2, Emily A. Day2, Ian P. Salt3, Gregory R. Steinberg2†† and D. Grahame Hardie1†† 1Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, Scotland, UK 2Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada 3Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, Scotland, UK Running title: Canagliflozin activates AMPK Corresponding authors: Dr. D. G. Hardie, Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, Scotland, UK; Dr. G.R. Steinberg, Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada Tel: +44 (1382) 384253; FAX: +44 (1382) 385507; e-mail: [email protected] Tel: +1 (905) 525-9140 ext.21691; email: [email protected] Word count in main text: 3,996 Number of Figures: 7 †these authors made equal contributions to this study ††joint corresponding authors Diabetes Publish Ahead of Print, published online July 5, 2016 Diabetes Page 2 of 37 Hawley et al Canagliflozin activates AMPK 2 ABSTRACT Canagliflozin, dapagliflozin and empagliflozin, all recently approved for treatment of Type 2 diabetes, were derived from the natural product phlorizin. They reduce hyperglycemia by inhibiting glucose re- uptake by SGLT2 in the kidney, without affecting intestinal glucose uptake by SGLT1.
    [Show full text]
  • Defective Galactose Oxidation in a Patient with Glycogen Storage Disease and Fanconi Syndrome
    Pediatr. Res. 17: 157-161 (1983) Defective Galactose Oxidation in a Patient with Glycogen Storage Disease and Fanconi Syndrome M. BRIVET,"" N. MOATTI, A. CORRIAT, A. LEMONNIER, AND M. ODIEVRE Laboratoire Central de Biochimie du Centre Hospitalier de Bichre, 94270 Kremlin-Bicetre, France [M. B., A. C.]; Faculte des Sciences Pharmaceutiques et Biologiques de I'Universite Paris-Sud, 92290 Chatenay-Malabry, France [N. M., A. L.]; and Faculte de Midecine de I'Universiti Paris-Sud et Unite de Recherches d'Hepatologie Infantile, INSERM U 56, 94270 Kremlin-Bicetre. France [M. 0.1 Summary The patient's diet was supplemented with 25-OH-cholecalci- ferol, phosphorus, calcium, and bicarbonate. With this treatment, Carbohydrate metabolism was studied in a child with atypical the serum phosphate concentration increased, but remained be- glycogen storage disease and Fanconi syndrome. Massive gluco- tween 0.8 and 1.0 mmole/liter, whereas the plasma carbon dioxide suria, partial resistance to glucagon and abnormal responses to level returned to normal (18-22 mmole/liter). Rickets was only carbohydrate loads, mainly in the form of major impairment of partially controlled. galactose utilization were found, as reported in previous cases. Increased blood lactate to pyruvate ratios, observed in a few cases of idiopathic Fanconi syndrome, were not present. [l-14ClGalac- METHODS tose oxidation was normal in erythrocytes, but reduced in fresh All studies of the patient and of the subjects who served as minced liver tissue, despite normal activities of hepatic galactoki- controls were undertaken after obtaining parental or personal nase, uridyltransferase, and UDP-glucose 4epirnerase in hornog- consent. enates of frozen liver.
    [Show full text]
  • Dr. Duke's Phytochemical and Ethnobotanical Databases List of Chemicals for Sedative
    Dr. Duke's Phytochemical and Ethnobotanical Databases List of Chemicals for Sedative Chemical Dosage (+)-BORNYL-ISOVALERATE -- (-)-DICENTRINE LD50=187 1,8-CINEOLE -- 2-METHYLBUT-3-ENE-2-OL -- 6-GINGEROL -- 6-SHOGAOL -- ACYLSPINOSIN -- ADENOSINE -- AKUAMMIDINE -- ALPHA-PINENE -- ALPHA-TERPINEOL -- AMYL-BUTYRATE -- AMYLASE -- ANEMONIN -- ANGELIC-ACID -- ANGELICIN ED=20-80 ANISATIN 0.03 mg/kg ANNOMONTINE -- APIGENIN 30-100 mg/kg ARECOLINE 1 mg/kg ASARONE -- ASCARIDOLE -- ATHEROSPERMINE -- BAICALIN -- BALDRINAL -- BENZALDEHYDE -- BENZYL-ALCOHOL -- Chemical Dosage BERBERASTINE -- BERBERINE -- BERGENIN -- BETA-AMYRIN-PALMITATE -- BETA-EUDESMOL -- BETA-PHENYLETHANOL -- BETA-RESERCYCLIC-ACID -- BORNEOL -- BORNYL-ACETATE -- BOSWELLIC-ACID 20-55 mg/kg ipr rat BRAHMINOSIDE -- BRAHMOSIDE -- BULBOCAPNINE -- BUTYL-PHTHALIDE -- CAFFEIC-ACID 500 mg CANNABIDIOLIC-ACID -- CANNABINOL ED=200 CARPACIN -- CARVONE -- CARYOPHYLLENE -- CHELIDONINE -- CHIKUSETSUSAPONIN -- CINNAMALDEHYDE -- CITRAL ED 1-32 mg/kg CITRAL 1 mg/kg CITRONELLAL ED=1 mg/kg CITRONELLOL -- 2 Chemical Dosage CODEINE -- COLUBRIN -- COLUBRINOSIDE -- CORYDINE -- CORYNANTHEINE -- COUMARIN -- CRYOGENINE -- CRYPTOCARYALACTONE 250 mg/kg CUMINALDEHYDE -- CUSSONOSIDE-A -- CYCLOSTACHINE-A -- DAIGREMONTIANIN -- DELTA-9-THC 10 mg/orl/man/day DESERPIDINE -- DESMETHOXYANGONIN 200 mg/kg ipr DIAZEPAM 40-200 ug/lg/3-4x/day DICENTRINE LD50=187 DIDROVALTRATUM -- DIHYDROKAWAIN -- DIHYDROMETHYSTICIN 60 mg/kg ipr DIHYDROVALTRATE -- DILLAPIOL ED50=1.57 DIMETHOXYALLYLBENZENE -- DIMETHYLVINYLCARBINOL -- DIPENTENE
    [Show full text]
  • Objectives Anti-Hyperglycemic Therapeutics
    9/22/2015 Some Newer Non-Insulin Therapies for Type 2 Diabetes:Present and future Faculty/presenter disclosure Speaker’s name: Dr. Robert G. Josse SGLT2 Inhibitors Grants/research support: Astra Zeneca, BMS, Boehringer Dopamine D2 Receptor Agonist Ingelheim, Eli Lilly, Janssen, Merck, NovoNordisk, Roche, Bile acid sequestrant sanofi, Consulting Fees: Astra Zeneca, BMS, Eli Lilly, Janssen, Merck, Dr Robert G Josse Division of Endocrinology & Metabolism Speakers bureau: Janssen, Astra Zeneca, BMS, Merck, St. Michael’s Hospital Professor of Medicine Stocks and Shares:None University of Toronto 100-year History of Objectives Anti-hyperglycemic Therapeutics 14 Discuss the mechanism of action of SGLT2 inhibitors, SGLT-2 inhibitor 12 Bromocriptine-QR dopamine D2 receptor agonists and bile acid sequestrants Bile acid sequestrant in the management of type 2 diabetes Number of 10 DPP-4 inhibitor classes of GLP-1 receptor agonist Amylinomimetic anti- 8 Glinide Basal insulin analogue Identify the benefits and risks of the newer non-insulin hyperglycemic Thiazolidinedione agents 6 Alpha-glucosidase inhibitor treatment options Phenformin Human Rapid-acting insulin analogue 4 Sulphonylurea insulin Metformin Intermediate-acting insulin Phenformin Describe the potential uses of these therapies in the 2 withdrawn Soluble insulin treatment of type 2 diabetes 0 1920 1940 1960 1980 2000 2020 Year UGDP, DCCT and UKPDS studies. Buse, JB © 1 9/22/2015 Renal handling of glucose Collecting (180 L/day) Glomerulus duct (1000 mg/L) Proximal =180 g/day Distal tubule S1 tubule Glucose ~90% filtration SGLT2 Inhibitors ~10% S3 Glucose reabsorption Loop No/minimal of Henle glucose excretion S1 segment of proximal tubule S3 segment of proximal tubule - ~90% glucose reabsorbed - ~10% glucose reabsorbed - Facilitated by SGLT2 - Facilitated by SGLT1 SGLT = Sodium-dependent glucose transporter Adapted from: 1.
    [Show full text]
  • The Dietary Phytochemical Myricetin Induces Ros-Dependent Breast Cancer Cell Death
    THE DIETARY PHYTOCHEMICAL MYRICETIN INDUCES ROS-DEPENDENT BREAST CANCER CELL DEATH by Allison F. Knickle Submitted in partial fulfilment of the requirements for the degree of Master of Science at Dalhousie University Halifax, Nova Scotia December 2014 © Copyright by Allison F. Knickle, 2014 Table of Contents List of Figures ....................................................................................................... iv List of Tables ........................................................................................................ vi Abstract ................................................................................................................ vii List of Abbreviations and Symbols Used ............................................................. viii Acknowledgements ............................................................................................. xiii CHAPTER 1 INTRODUCTION ............................................................................. 1 1.1. Cancer ...................................................................................................................... 1 1.2 Breast Cancer ........................................................................................................... 1 1.2.1 Triple-negative breast cancer .............................................................................. 3 1.3 Cell death .................................................................................................................. 4 1.3.1 Apoptosis ............................................................................................................
    [Show full text]
  • (Lithocarpus Polystachyus Rehd.) Based Upon Location, Harvesting Time, Leaf Age
    Juan Yang et al., J.Chem.Soc.Pak., Vol. 40, No. 01, 2018 158 Identification and Quantitative Evaluation of Major Sweet Ingredients in Sweet Tea (Lithocarpus polystachyus Rehd.) Based Upon Location, Harvesting Time, Leaf Age Juan Yang, Yuyi Huang, Zhi Yang, Chao Zhou and Xujia Hu* Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, P.R. China. [email protected]* (Received on 11th April 2016, accepted in revised form 13th September 2017) Summary: Lithocarpus polystachyus Rehd. (Sweet Tea) is a traditional sweet tea plant. Flavonoids are the essential sweet active constituents of Sweet Tea, and they have direct relationship with the sweet tonic beverage and traditional herb. In this work, the chemical components of the sweeteners isolated from Sweet Tea were identified as 3-hydroxy phlorizin (1), phlorizin (2), kaempferol-3-O-β-D-glucoside (3) and trilobatin (4) by ESI•-MS and NMR analyses. Quantitative analysis of the flavonoid compounds in Sweet Tea from Yunnan province of China indicated their content was influenced by harvesting time and leaf age. Phlorizin and trilobatin were identified as principal flavonoids in Sweet Tea. The highest concentration of trilobatin was in April, and the highest concentration of phlorizin was in November. The flavonoids content was the highest in young leaves and decreased at mature stage. Moreover, considerable variations of flavonoids content in Sweet Tea from three locations (Yunnan, Hunan, Jiangxi) were observed. It was concluded that the quality of Sweet Tea is greatly influenced by harvesting time, location and leaf age. Therefore, the artificial cultivation of Sweet Tea is necessary to ensure its optimal quality and suitability for specific applications.
    [Show full text]
  • Phytochemistry / Fitoquímica
    Botanical Sciences 98(4): 545-553. 2020 Received: April 20, 2020, Accepted: July 25, 2020 DOI: 10.17129/botsci.2624 On line first: October 12, 2020 Phytochemistry / Fitoquímica BIOLOGICAL ACTIVITY AND FLAVONOID PROFILE OF FIVE SPECIES OF THE BURSERA GENUS ACTIVIDAD BIOLÓGICA Y PERFIL DE FLAVONOIDES DE CINCO ESPECIES DEL GÉNERO BURSERA ID MA. BEATRIZ SÁNCHEZ-MONROY1, ID ANA MARÍA GARCÍA-BORES2, ID JOSÉ LUIS CONTRERAS-JIMÉNEZ 3, ID DAVID EDUARDO TORRES1, ID RUBÉN SAN MIGUEL-CHÁVEZ4, ID PATRICIA GUEVARA-FEFER1* 1Departamento de Ecología y Recursos Naturales. Facultad de Ciencias. Universidad Nacional Autónoma de México. Ciudad de México, Mexico. 2Laboratorio de Fitoquímica, UBIPRO, Facultad de Estudios Superiores-Iztacala. Universidad Nacional Autónoma de México, Tlalnepantla, Mexico. 3Benemérita Universidad Autónoma de Puebla, Puebla, Mexico. 4Laboratorio de Fitoquímica, Colegio de Postgraduados, Montecillo, CP 56230, Estado de México, Mexico. *Author for correspondence: [email protected] Abstract Background: The genus Bursera Jacq. ex. L. concentrates its diversity in Mexico. Among the secondary metabolites that can be isolated from organic its extracts are flavonoids and lignans. Research question: Do the biological activity of the hydroalcoholic extracts from five Bursera species studied depend on their flavonoid content? Study site: Oaxaca, Mexico. Methods: The extracts of B. aptera Ramírez, B. fagaroides (Kunth) Engl., B. schlechtendalii Engl., B. galeottiana Engl., B. morelensis Ramírez were analysed by High Resolution Liquid Chromatography (HPLC) to determine their flavonoid composition. The antiradical DPPH, anti-inflammatory, antibacterial and antifungal activities of the extracts were determined. Results: Phlorizin and quercetin were conserved in both stems and leaves of the five species studied. The phloretin was present only in the leaves of B.
    [Show full text]
  • Glucose Transporters As a Target for Anticancer Therapy
    cancers Review Glucose Transporters as a Target for Anticancer Therapy Monika Pliszka and Leszek Szablewski * Chair and Department of General Biology and Parasitology, Medical University of Warsaw, 5 Chalubinskiego Str., 02-004 Warsaw, Poland; [email protected] * Correspondence: [email protected]; Tel.: +48-22-621-26-07 Simple Summary: For mammalian cells, glucose is a major source of energy. In the presence of oxygen, a complete breakdown of glucose generates 36 molecules of ATP from one molecule of glucose. Hypoxia is a hallmark of cancer; therefore, cancer cells prefer the process of glycolysis, which generates only two molecules of ATP from one molecule of glucose, and cancer cells need more molecules of glucose in comparison with normal cells. Increased uptake of glucose by cancer cells is due to increased expression of glucose transporters. However, overexpression of glucose transporters, promoting the process of carcinogenesis, and increasing aggressiveness and invasiveness of tumors, may have also a beneficial effect. For example, upregulation of glucose transporters is used in diagnostic techniques such as FDG-PET. Therapeutic inhibition of glucose transporters may be a method of treatment of cancer patients. On the other hand, upregulation of glucose transporters, which are used in radioiodine therapy, can help patients with cancers. Abstract: Tumor growth causes cancer cells to become hypoxic. A hypoxic condition is a hallmark of cancer. Metabolism of cancer cells differs from metabolism of normal cells. Cancer cells prefer the process of glycolysis as a source of ATP. Process of glycolysis generates only two molecules of ATP per one molecule of glucose, whereas the complete oxidative breakdown of one molecule of glucose yields 36 molecules of ATP.
    [Show full text]
  • Isolation of Kaempferol Glycosides from Ginkgo Biloba Leaves and Synthesis, Identification and Quantification of Their Major in Vivo Metabolites
    Isolation of Kaempferol Glycosides from Ginkgo biloba Leaves and Synthesis, Identification and Quantification of their major in vivo Metabolites DISSERTATION ZUR ERLANGUNG DES DOKTORGRADES DER NATURWISSENSCHAFTEN (DR. RER. NAT.) DER NATURWISSENSCHAFTLICHEN FAKULTÄT IV DER UNIVERSITÄT REGENSBURG vorgelegt von Daniel Bücherl aus Dieterskirchen 2013 Die vorliegende Arbeit entstand im Zeitraum vom März 2010 bis Oktober 2013 unter der Leitung von Herrn Prof. Dr. Jörg Heilmann am Lehrstuhl für Pharmazeutische Biologie am Institut für Pharmazie der Naturwissenschaflichen Fakultät IV – Chemie und Pharmazie – der Universität Regensburg. Das Promotionsgesuch wurde eingereicht im Oktober 2013 Tag der mündlichen Prüfung: 29.11.2013 Prüfungsausschuss: Prof. Dr. Gerhard Franz (Vorsitzender) Prof. Dr. Jörg Heilmann (Erstgutachter) Prof. Dr. Joachim Wegener (Zweitgutachter) Prof. Dr. Frank-Michael Matysik (Drittprüfer) Was du für den Gipfel hältst, ist nur eine Stufe. Lucius Annaeus Seneca Danksagung Ein großes Dankeschön geht an alle die mir während meiner Promotion hilfreich zur Seite gestanden haben. Besonders möchte ich danken: Prof. Dr. Jörg Heilmann für das Vertrauen und die Möglichkeit mir dieses interessante Projekt zu überlassen, für zahlreiche wertvolle Diskussionen und für die lehrreiche und schöne Zeit in seiner Arbeitsgruppe; Dr. Egon Koch und Dr. Clemens Erdelmeier der Dr. Willmar Schwabe GmbH und Co. KG, für die Mitbetreuung dieser Arbeit, ihre zahlreichen wertvollen Beiträge, die hilfreichen Diskussionen, die Bereitstellung der Flavonoidfraktionen von EGb 761®, und die Durchführung der Fütterungsexperimente an den Ratten; Dr. Willmar Schwabe GmbH und Co. KG für die grosszügige finanzielle Unterstützung dieser Arbeit; meinen Kolleginnen und Kollegen am Lehrstuhl für Pharmazeutische Biologie sowie auch allen Praktikanten, für die freundliche Aufnahme in der Gruppe, das wunderbare Arbeitsklima und ihre Hilfsbereitsschaft.
    [Show full text]