Analysis of S tructure-Activity R elationships of auxin – lik e m oleculesV on der Naurssw enscafcl he Faktu rd Gottfried Wilhelm Leibniz Univrsiät Hnnovr zur Erl angung des G rades eines Doktors der N aturwissenschaften Dr. rer. nat.genehmigte Dissertation vonMaster en Biología Vegetal Noel Ferro Diazgeboren am 28. 03.1971 in Havanna, Ku ba2006e a t e eäl n ith i tReferent:Pro f. Dr. H.-J. Ja cobsenKo rreferent:PD Dr. Th. Bre dowTa e r Pro mo io : 07. 07. 2006 n t d gAbstractAuxins hav e been the first plan t growth regulators discover ed sev er al decades ago. Th ey play a complex an d importan t role in the den dritic net work of the physiolog ical proces ses in plan ts. N ev er thel es s, a correl ation bet ween thei r chem ical structure an d its biolog ical implication could not be fou nd. Man y theor ies on correl ations of structure an d activity hav e been dev el oped, which are based mainly on chem ical intuition. Th is is the first ap proach to ap ply met hod s of computational chem istry combined with biostatistics. By the ap plication of thes e met hod s, the distribution of the outer molecular orbitals on the molecule can be iden tified an d also thei r impact on the biolog ical activity. Th e use of Mol ecular Quan tum Similarity Meas ures (MQSM) on structures of au xin-like molecules res ulted in a concep tual fram ew ork to classify au xin structures from a biostatistical point of view .
CHAPTER 1: GENERAL INTRODUCTION..............................................................................................................................1
Plant growth regulators, overview..................................................................................................................2 Evolution of auxin concept..............................................................................................................................3 Auxin perception, signal transduction and gene expression...........................................................................6 Structure-activity ............................................................................................................................................8 Chemical approach: .....................................................................................................................................................9 Physico-chemical approach........................................................................................................................................10 Binding site models.....................................................................................................................................................11 Literature ......................................................................................................................................................15
CHAPTER 2: STRUCTURE–ACTIVITY ANALYSIS ON ECDYSTEROIDS: A STRUCTURAL AND QUANTUM CHEMICAL APPROACH BASED ON TWO BIOLOGICAL SYSTEMS....................................................21
CHAPTER 3: COULOMB AND OVERLAP SELF - SIMILARITIES: A COMPARATIVE SELECTIVITY ANALYSIS OF STRUCTURE - FUNCTION RELATIONSHIPS FOR AUXIN - LIKE MOLECULES........................34
CHAPTER 4: UNREVEALED STRUCTURAL REQUIREMENTS FOR AUXIN - LIKE MOLECULES BY THEORETICAL AND EXPERIMENTAL EVIDENCES................................................................................35
Plant bioassays: a poor structural mirror ...................................................................................................63 Auxin, its molecular diversity and pleiotropic activity..................................................................................64 How to face the problems..............................................................................................................................65 Two sets of structural requirements for auxin-like molecules.................................................................... 68 General reflexions....................................................................................................................................... 69 Outlook and future prospect........................................................................................................................ 70 Literature..................................................................................................................................................... 71