Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 20 for “"Diterpenoids"”.
-
Investigating factors that influence microalgae production platforms for diterpenoids in laboratory and outdoor conditions
Photosynthetic microalgae offer a biotechnological solution to current climate concerns and the growing demand for food, bioproducts and bulk chemicals. As naturally efficient producers of carbohydrates, lipids, proteins and pigments, microalgae are a sustainable platform in which to realise the …
-
A new synthesis of enantiomerically pure bicyclic ketones. Total synthesis of the diterpenoids (-)-Kolavenol and (-)-Agelasine B
… syntheses of the optically active clerodane diterpenoids (-)-kolavenol (65) and (-)-agelasine B (31). (-)-Kolavenol (65) was prepared in 14 steps and 19.4% overall yield from the enone 64. Thus, the alcohol 165 was oxidized and the resulting ketone 47 was converted to the nitriles 215. The …
-
Synthesis and Biological Evaluation of Paclitaxel Analogs
… is a member of a large family of taxane diterpenoids. Paclitaxel is extensively used for the treatment of solid tumors, particularly those of the breasts and ovaries. In order to obtain additional information about the mechanism of action of paclitaxel and the environment of the …
-
I. Isolation and Characterization of Bioactive Compounds From Suriname and Madagascar flora. II. A Synthetic Approach to Lucilactaene
… sp (Icacinaceae) gave three new and five known diterpenoids. Pentopetia androsaemifolia (Apocynaceae) afforded one new and three known cardenolide glycosides. Physalis angulata (Solanaceae) yielded seven known physalins. Roupellina boivinnii (Apocynaceae) yielded four known and three new …
-
Phytochemical studies on traditional medicinal plants with antimalarial activities
… 3β-Hydroxy-20(29)-Lupen-28-oic acid (42)); two diterpenoids (8-Abietene-7 β,13 β -diol (45) and cariocal (51)); one flavonoid ( 5-Hydroxy:.4' ,6, 7-trimethoxyflavone ( 44)) and one flavonolignan ( 11-0- acetyl hydnocarpin (62)). In addition, one analogue of 7α-hydroxyroyleanone (41) (which was …
-
Stereospecific Syntheses from Podocarpic Acid
… of a series of 6-bromo-7-oxo derivatives of diterpenoids possessing an aromatic ring-C is discussed and the assignment of configuration of the 6-bromo substituents from n.m.r. and n.0.e. data is examined. A preliminary investigation into the possibility of preparing a 9a-methyl steroidal …
-
SYNTHESES AND METAL MEDIATED REACTION CHEMISTRY OF 2-SILYL-1,3-DIENES
… relative and absolute stereochemistries. Diterpenoids containing the clerodane carbon skeleton are prevalent as secondary metabolites. Synthetic approaches to the trans-clerodanes are known, but cis-clerodanes are rare. This proposed methodology will also allow the scientific community to …
-
Investigation of cytochrome P450s in the biosynthesis of rice phytoalexins
… reactions on LRD olefins to produce bioactive diterpenoids. Intriguingly, two biosynthetic gene clusters (BGCs), composed of CYPs and upstream cyclases dedicated to LRD production, have been discovered in the rice genome. The chromosome two BGC (c2BGC) contains a set of closely related CYP76M …
-
Cyclodextrin Assisted Enantiomeric Recognition of Amino Acid Imides and Toward Synthesis of Dolabellane Diterpenoid B
… constants of this host-guest system. Dolabellane diterpenoids share the unique feature of a trans-bicyclo[9.3.0]tetradecane and most of them express antimicrobial, antitumor and antiviral activities. They are primarily obtained from marine resources. Dolabellane diterpenoid B was isolated from the …
-
Investigating the evolution of cytochromes P450 involved in GA biosynthesis
… Arabidopsis produces no labdane-related diterpenoids other than gibberellins, whereas rice produces a wide range of such natural products as antibiotic phytoalexins or allelochemicals. While rice contains several kaurene oxidase homologs, only OsKO2 (CYP701A6) is required for gibberellin …
-
Isolation and Structure Elucidation of Anticancer and Antimalarial Natural Products
… and five known antiproliferative diterpenoids from Malleastrum rakotozafyi (Meliceae); and 10 known compounds from Monoporus sp. (Myrsinaceae), Premna corymbosa (Verbenaceae), Premna perplexanes (Verbenaceae), Epallage longipes (Asteraceae), and Cinnamosma fragrans (Canellaceae).
-
Biological activity of Sinularia notanda
… new compounds. Annually a variety of cembrane diterpenoids with a range of biological activities are reportedly isolated from marine soft coral, and most notably these compounds possess anticancer properties. The investigation of a marine soft coral, Sinularia notanda, for novel bioactive …
-
Anticancer and antibiotic leads from marine organis
… including tetracyclic aromatic alkaloids, diterpenoids and pyrroloaminopropylimidazole alkaloids were purified. Bioassay-guided isolation from marine P. aeruginosa collected in the Gulf of Mexico afforded 15 known antibiotics including two phenazines, six 2-alkyl-4-quinolones, and seven …
-
Indole diterpenoid secondary metabolites produced by the Epichloë festucae var. lolii – Lolium perenne symbiosis.
… alkaloids. The indole moiety of known indole diterpenoids was modified to a six-membered ring in the novel compounds A – D (64 – 67), with the right side of these molecules similar to that of lolitrem B (3) and terpendole C (49). Compounds A – D (64 – 67) differ in the stereochemistry and …
-
Geochemical tools and paleoclimate clues : multi-molecular and isotopic investigations of tropical marine sediments and alpine ice
… polycyclic aromatic hydrocarbons (PAHs), and diterpenoids. Variability in the distributions of these compounds between different cores demonstrated that the lipid organic fraction in each core was representative of mostly local inputs. To further investigate natural inputs, several …
-
Total syntheses of (±)-dracephalone A and (±)-dracocequinones A and B, progress towards a total synthesis of cassiabudanols A and B, and synthetic studies towards total synthesis of N-oxy-diketopiperazine containing natural products.
In 2022 we reported the first total syntheses of 20-nor-abietanoids (±)-dracocephalone A and (±)-dracocequinones A and B. Our synthesis originally involved an isobenzofuran intramolecular Diels-Alder, a strategy that eventually evolved into a Lewis acid-mediated spirocyclization in a highly …
-
Isolation and characterization of African marine natural products and repositioning of the natural product antibiotic fusidic acid and privileged benzimidazole scaffold for tuberculosis and malaria
… secondary metabolite classes of labdane diterpenoids, polyether triterpenoids and sterols, and a glycolipid, which is reported herein for the first time from the genus. The compounds displayed low micromolar to poor in vitro antiproliferative activity towards the human breast (MDA-MB-231) …
-
Complex botanical natural products: Synthesis of cephalotaxus esters and of the C19-diterpenoid skeleton of aconitum and delphinium alkaloids
The Cephalotaxus esters are a class of alkaloids extracted from plants of the Cephalotaxus genus and have been shown to be potent inhibitors of P-388 murine leukemia cells. While direct acylation of cephalotaxine has been reported to be difficult, the construction and acylation of cephalotaxine …
-
Ι. ΜΕΛΕΤΗ ΤΩΝ ΧΗΜΙΚΩΝ ΣΥΣΤΑΤΙΚΩΝ ΤΟΥ ΦΥΤΟΥ CISTUS INCANUS SUBSP. CRETICUS (L.) HEYWOOD ΙΙ. ΑΠΟΜΟΝΩΣΗ-ΔΟΜΗ-ΣΥΝΘΕΣΗ ΝΕΟΥ ΦΛΑΒΟΝΟΕΙΔΟΥΣ ΤΟΥ ΦΥΤΟΥ KALANCHOE PROLIFERA R. HAMET
THE LEAVES OF CISTUS INCANUS SUBSP CRETICUS (L.) HEYWOOD COLLECTED IN CRETE ANDSTUDIED IN THE FIRST PART OF THIS THESIS. FROM THE PETROLERUM ETHER EXTRACT AND ETHER EXTRACT SEVEN LABDANE -TYPE DITERPENES HAVE BENEN ISOLATED AND IDENTIFIED. THE STRUCTURES OF ALL THE COMPOUNDS WERE DETERMINED BY MS …