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The use of functionalised lithium amides in the total synthesis of alkaloidsLee, James A. January 2012 (has links)
This thesis is concerned with the application of the conjugate addition of functionalised lithium amides in the asymmetric syntheses of (−)-morphine and all members of the homalium alkaloids. Chapter 1 introduces the conjugate addition reaction as an important bond forming reaction, and explores its utility in the asymmetric synthesis of a variety of natural products. The conjugate addition of secondary lithium amides derived from α-methylbenzylamine is discussed, along with its application to the asymmetric synthesis of alkaloids. Chapter 2 describes two distinct attempts towards the asymmetric synthesis of (−)-morphine, both reliant upon the lithium amide conjugate addition and an intramolecular Diels-Alder reaction to set the five required stereogenic centres. The use of the novel and highly functionalised reagent lithium (R)-N-[2′-(7-methoxybenzofuran-3-yl)ethyl]-N-(α-methylbenzyl)amide and its derivatives is reported. Chapter 3 focuses on the use of the novel reagent lithium (R)-N-(3-chloroprop-1-yl)-N-(α-methylbenzyl)amide and its derivatives in the asymmetric synthesis of two of the homalium alkaloids, (−)-(S,S)-homaline and (−)-(R,R)-hopromine, culminating in the most efficient syntheses of these alkaloids to date. Further, a sample of the (4′R,4′′S)-diastereoisomer of hopromine was synthesised, serving to confirm the proposed absolute configuration within natural (−)-(R,R)-hopromine. Chapter 4 extends the methodology developed in chapter 3 to the asymmetric synthesis of all possible diastereoisomers of the remaining homalium alkaloids, (−)-hopromalinol and (−)-hoprominol. These syntheses were used to propose the absolute configurations within these alkaloids, and therefore represented the first asymmetric syntheses of natural (−)-(4′S,4″R,2‴R)-hopromalinol and (−)-(R,R,R)-hoprominol. Chapter 5 contains full experimental procedures and characterisation data for all compounds synthesised in Chapters 2, 3 and 4.
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Towards the total synthesis of calyciphylline A-type Daphniphyllum alkaloidsMichaelides, Iacovos Neal January 2014 (has links)
This thesis details the studies towards the total synthesis of the calyciphylline A-type Daphniphyllum alkaloids, with a particular focus on daphniyunnine D (23). Chapter 1 introduces these biologically and synthetically interesting polycyclic natural products and describes our designed approach towards their synthesis. Separate studies targeting the construction of two tricyclic ring systems have been developed. These provide rapid entry to synthetically versatile intermediates, allowing for the potential synthesis of numerous members of the alkaloid family. Chapter 2 describes the first study which focuses on the construction of the main tricyclic [6‒5‒7] ACD core 172 via a proton transfer/IMDAF reaction cascade as the main step. Large scale synthesis of the precursor to this cascade 164 has allowed for the successful investigation of an asymmetric variant giving rise to an enantioenriched adduct 104. Chapter 3 describes a novel design for the construction of the [7‒5‒5] DEF tricycle common to 100+ Daphniphyllum alkaloids. An IMPKR, double-bond migration, allylic oxygenation protocol was first validated on a model system and later applied in combination with the synthetic route developed in chapter 2 to achieve the construction of the [6‒5‒7‒5‒5] ACDEF pentacycle 249. Chapter 4 focuses on the construction of the piperidine ring B via an intramolecular gold-catalysed 6-exo-trig hydroalkylation. During the development of the route to daphniyunnine D, various intermediates were afforded which were further elaborated to provide appropriate cyclisation substrates for this study. Their synthesis combined with proof of principle experiments for the desired cyclisation conclude this dissertation work.
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LOLINE ALKALOID BIOSYNTHESIS IN <i>NEOTYPHODIUM UNCINATUM</i>, A FUNGAL ENDOPHYTE OF <i>LOLIUM PRATENSE</i>Blankenship, Jimmy Douglas 01 January 2004 (has links)
Some endophytes in mutualistic associations with Festuca, Lolium and other grass species produce insecticidal loline alkaloids (1-aminopyrrolizidines; LA). These loline alkaloids have a saturated pyrrolizidine ring system (two-rings sharing a carbon and nitrogen atom), a 1-amine substituted with methyl, acetyl, or formyl groups, and an oxygen bridge between C-2 and C-7. The development of a reliable system of production of LA in cultures of the Lolium pratense (meadow fescue) endophyte, Neotyphodium uncinatum, facilitated work on the LA biosynthetic pathway. N. uncinatum produced norloline, loline, methylloline, N-acetylnorloline (NANL), N-formylloline (NFL), and N-acetylloline as detected in culture filtrates. The total production of the two most abundant alkaloids, NANL and NFL, approached 1000 g ml-1 of fungal filtrate. 1H and 13C chemical shifts were previously reported for this group of alkaloids. Extraction and synthesis of sufficient quantities of the alkaloids allowed determination of previously unknown 15N chemical shifts of some LA. Knowledge of 13C and 15N chemical shifts allowed identification of precursors by feeding stable-isotope-labeled compounds. Initially, due to structural similarity to other plant pyrrolizidines, this study examined putrescine and spermidine as possible precursors to LA. Feeding of 14C putrescine to the fungal cultures failed to demonstrate any enrichment in the LA, but enriched spermidine. In contrast, cultures fed with positionally labeled 2H, 13C and 15N amino acids namely, L-ornithine, L-proline, L-aspartate, L-homoserine, and L-methionine demonstrated specific isotopic enrichment in NFL. Determination of the enrichment from the labeled amino acids utilized 13C and 15 N NMR (nuclear magnetic resonance) and gas chromatography-mass spectroscopy (GC-MS). This study allowed the biosynthetic origins of all carbons and nitrogens of NFL to be determined. NFL incorporated L-proline into the B-ring and L-homoserine into the A-ring and 1-amine. The results strongly indicated that polyamines are not precursors of LA and implicated a novel biochemical pathway for the synthesis of LA.
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USE OF MTB-100TM, PROVIDED THROUGH A MINERAL MIX, TO REDUCE TOXICITY WHEN LACTATING BEEF COWS GRAZE ENDOPHYTE-INFECTED TALL FESCUEHoar, Melanie E 01 January 2013 (has links)
Two experiments were conducted at the University of Kentucky, Eden Shale Farm, Owenton, KY to evaluate the use of MTB-100TM (Alltech, Inc., Nicholasville, KY) to alleviate the symptoms of fescue toxicity when lactating Angus x Beefmaster cows and their calves grazed endophyte-infected KY-31 tall fescue. Experiment 1 provided a carbohydrate based toxin adsorbent, MTB-100TM, ad libitum in a commercial mineral supplement to project a daily consumption rate of 0, 20 or 40 g of MTB-100TM per cow. Cows were weighed, assigned a body condition score (BCS) and hair coat score (HC), rectal temperatures were recorded and fecal grab samples were taken for ergovaline (EV) and lysergic acid (LA) analysis every 35 days for three grazing seasons (May to September). Calves were also weighed and assigned a HC score. Although MTB-100TM did not improve cow or calf performance, cows older than 4 years and those with greater Beefmaster breeding exhibited a higher tolerance to fescue toxicity than 2 and 3-yr-olds and cows with greater Angus breeding.
Experiment 2 was conducted to evaluate the response of lactating beef cows and their calves to strategic supplementation with MTB-100TM. MTB-100TM was mixed with a complete mineral so daily intake was projected to be 0 or 20 g/cow. The experimental period extended from May 5 to October 2 and was divided into 3 strategic periods: P1 = May 5 to July 5; P2 = July 5 to August 31; P3 = August 31 to October 2. Treatments were either 0 or 20 g•cow-1•d-1 MTB-100TM within a period (Treatment 1 = 0, 0, 0; Treatment 2 = 20, 0, 20; Treatment 3 = 0, 20, 0; Treatment 4 = 20, 20, 0; and Treatment 5 = 20, 20, 20). Cow and calf performance was measured the same as Exp. 1, but every 21 days. Supplementation early in the grazing season tended to improve cow weight gain and body condition; however, there was no effect on calf performance. Fecal output of EV and LA did not increase in either experiment with supplementation. In conclusion, strategically invoked MTB-100TM consumption can increase performance of cows grazing endophyte-infected tall fescue forage.
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Effects of the anticarcinogen indole-3-carbinol on Xenobiotic metabolizing enzymes in rainbow troutSwanson, Hollie I. 03 June 1988 (has links)
Indole-3-carbinol (I3C) inhibits chemically induced tumor
formation in rodents and rainbow trout. This study examines the
effect of I3C and its analog, indole-3-acetonitrile (I3N) on
xenobiotic-metabolizing enzyme systems. The modulation of these enzyme
systems have been shown to have significant effects on the
interaction of chemical carcinogens and cellular constituents. Rainbow
trout were fed 500, 1000 and 2000 ppm dietary levels of I3C and 50,
500 and 1000 ppm dietary levels of I3N for 8 days. β-napthoflavone
(BNF), which is also an effective anticarcinogen in the trout, was
fed at a 500 ppm dietary level and was used as a positive LM4b (a
cytochrome P-450 isozyme) inducing control. Enzyme activities assayed
were: ethoxyresorufin-O-deethylase (EROD), ethoxycoumarin-O-deethylase
(ECOD), glutathione S-transferase (GST), and uridine
diphosphoglucuronosyl transferase (UDPGT). Total cytochrome P-450
content was determined spectrophotometrically by the CO reduced
method. The specific P-450 isozymes, LM2 and LM4b, were detected
quantitatively using the western blot method. The BNF diet induced EROD and ECOD activities by an average of 17 fold and 5.5 fold,
respectively. Total P-450 content was increased 2-fold; the P-450
isozyme LM4b was induced more than 5-fold, but LM2 content remained
unchanged. This diet increased UDPGT activity 1.5-2-fold, but GST
activity was not induced by dietary BNF. Neither I3C nor I3N induced
the activity levels of the enzymes assayed at any administered dietary
levels, which have previously shown to inhibit tumor formation and
reduce formation of carcinogen-DNA adducts. Thus, the anticarcinogenic
mechanism of I3C may proceed in trout by mechanisms other than enzyme
induction. Further experiments on the effect of I3C and I3C acid
condensation products (RXN) on in vitro AFB1-DNA binding resulted in a
40% and 48% inhibition of AFB1-DNA binding by I3C and RXN,
respectively. Additions of RXN at levels much lower than those
estimated to exist in vivo in hepatic tissue resulted in a significant
reduction in AFB1-DNA formation suggesting that even small levels of
RXN offers protection against the genotoxic effect of AFB1. However,
in vitro additions of neither I3C nor RXN had an effect on DNA binding
using AFBI-CI₂, an aflatoxin analog that does not require enzymatic
activation. These results suggest that the primary mechanism for I3C
inhibition of AFB1 induced carcinogenesis may proceed by inhibiton of
formation of the ultimate electrophile, i.e. by reversible inhibition
of cytochrome P-450. / Graduation date: 1989
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Intramolecular Cope-Type Hydroamination of Alkenes in the Synthesis of Alkaloids: Total Synthesis of (±)-Coniine and (±)-Desbromoarborescidine A and Studies on a Novel Amination Strategy Towards Manzamine ADion, Isabelle 16 July 2012 (has links)
Intramolecular hydroamination represents a potentially general, simple strategy to access various nitrogen heterocycles. While important progress has been accomplished in recent years, six-membered ring formation via alkene hydroamination is typically difficult and limited to terminal alkenes, suggesting that only 2-methylpiperidines can be accessed reliably with current methods. As part of the Beauchemin group efforts on metal-free concerted hydroamination methods, the first part of this thesis describes the development of a Cope-type hydroamination-Meisenheimer rearrangement (CHMR) sequence that is applicable in inter- and intramolecular reactions. Data acquired from optimization on a difficult substrate (coniine) and the successful application of the CHMR sequence to the syntheses of N-norreticuline and 10-desbromoarborescidine are reported. The amination of alkenes is surprisingly scarcely used in the synthesis of complex alkaloids despite its potential for the construction of structurally challenging molecules while avoiding functional group interconversions. Hence, the second part of this thesis describes the studies on a novel amination sequence, consisting of an intermolecular Diels-Alder followed by an intramolecular hydroamination reaction, in the efforts towards the synthesis of biologically active and structurally complex Manzamine A. As such, the synthesis of the model substrates, including the development of a novel family of aminodienes, as well as the assessment of their reactivity towards [4+2] cycloadditions is reported.
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Neurotropní a antioxidační aktivita vybraných druhů jednoděložných alkaloidních rostlin. VIII. / Neurotropic and antioxidative activity of some selected species of monocotyledonous alkaloidal plants in vitro. VIII.Breiterová, Kateřina January 2015 (has links)
Author: Kateřina Breiterová Title: Neurotropic and antioxidative activity of some selected species of monocotyledonous alkaloidal plants in vitro. VIII. Diploma thesis Charles Univerzity in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology 2015, 101 p. More than 50 % cases of dementia are nowadays caused byAlzheimer's disease (AD). AD is a progressive neurodegenerative disease and it causes gradual memory loss, disorientation and behavioral disorders which affect patient's social and occupational life. AD is characteristic by loss of neurons in some regions of brain - for example hippocampus and cortex. Ethiopathogenesis of this disease is not completely known - that is why the treatment is still just symptomatic. Formation of β-amyloid deposits in brain tissue plays an important role - it is a protein which creates extracellular plagues around neurites and causes their degeneration and death. Intracellular tangles are made up of the changed τ-protein. These tangles also cause death of the neuronal cell. The degeneration of neurons is supported by reactive oxygen radicals too. The another problem is a glutamatergic system disorder. This set of excitatory amino acids is important for correct long-term memory formation. Patients with AD suffer from...
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Alkaloidy rostlin čeledi Amaryllidaceae a jejich biologická aktivita 1. / Alkaloids of the family Amaryllidaceae and their biological activity 1.Mišáková, Kamila January 2014 (has links)
Mišáková K: Alkaloids of the Amaryllidaceae family and their biological activity 1. Diploma thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology, Hradec Králové, 2014, 63 p. The aim of the diploma thesis was a preparation of alkaloidal extract from Nerine Bowdenii to izolation of 2 pure alkaloids by column and thin layer chromatography. Subsequently these two alkaloids were subjected to structural MS and NMR analysis and tested for biological activity against human cholinesterases (HuAChE and HuBuChE) and for antioxidant and cytotoxic activity. Isolated substances were identified as ambelline and undulatine alkaloids, which have been already described previously in this plant. In the test for determining cholinesterase inhibitory activity of ambelline and undulatine the following values were measured; for ambelline: IC50, HuAChE = 169 ± 7 μM a IC50, HuBuChE = 985 ± 25 μM, for undulatine: IC50, HuAChE = 23,52 ± 1,19 μM a IC50, HuBuChE > 1000 μM. Galanthamin (IC50, HuAChE = 1,71 ± 0,007 μM, IC50, HuBuChE = 42,30± 1,30 μM), huperzin A (IC50, HuAChE = 0,033 ± 0,001 μM, IC50, HuBuChE > 1000 μM) and eserin (IC50, HuAChE = 0,063 ± 0,001 μM, IC50, HuBuChE = 0,130 ± 0,004 μM) were used like a positive controls. In the test for...
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Biologická aktivita obsahových látek rostlin XXVII. Alkaloidy Fumaria officinalis L. a jejich účinek na acetylcholinesterasu a butyrylcholinesterasu. / Biological activity of plants metabolites. XXVII. Alkaloids of Fumaria officinalis L. and their effect on acetylcholinesterase and butyrylcholinesterase.Hulcová, Daniela January 2014 (has links)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany and Ecology Candidate: Daniela Hulcová Consultant: Prof. RNDr. Lubomír Opletal, CSc. Title of Diploma Thesis: Biological aktivity of plants metabolites. XXVII. Alkaloids of Fumaria officinalis L. and their effect on acetylcholinesterase and butyrylcholinesterase The summary ethanolic and diethylether extract were prepared from the herbs of a plant Fumaria officinalis L. We have obtained 201 fractions from this extract by column chromatography on the neutral Al2O3 (aluminium oxide). Joined fraction 68-76 were processed by thin layer chromatography, and 3 substances were obtained in pure state: DH-1, DH-2, DH-3. These 3 compounds were identified as protopine, (+)-fumariline and N- methylcorydaldine by the comparison with the literature and results of MS and NMR. These alkaloids were tested for the inhibitory activity against human erythrocytic acetylcholinesterase and plasmatic butyrylcholinesterase by Ellman`s method. The isolated alkaloids did not show any significant inhibitory activity (IC50, µM) compared with the standard galanthamine (IC50, µM; AChE 1,710 ± 0,065, BuChE 42,30 ± 1,30): protopin: AChE: 345,42 ± 31,12, BuChE: 239,66 ± 20,89, (+)-fumarilin: AChE: 2939,2 ± 309,41, BuChE: 330,62 ±...
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Biologická aktivita sekundárních metabolitů rostlin V. Alkaloidy Vinca minor L. / Biological aktivity of secondary plants metabolites V. Alkaloids of Vinca minor L.Bouz, Lukáš January 2016 (has links)
Bouz L.: Biological activity of secondary plants metabolites V. Alkaloids of Vinca minor L. Diploma thesis, Charles University, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology, Hradec Králové 2016. Summary extract obtained from dried aerial parts of Vinca minor L. was separated by column chromatography with petrol, chloroform and ethanol to 531 fractions. By further separation of fractions, following preparative thin layer chromatography and crystallization 2 alkaloidal compounds marked LB-2 and LB-3 were isolated. These compounds were identified by GC/MS, 1 H- and 13 C-NMR spectroscopy and by use of physical-chemical methods. The structure of compounds were elucidated as indole alkaloids (+)-vincaminoreine (LB-2) and (+)-vincamine (LB-3). Both substances were tested for their inhibition activity against human cholinesterases. (+)-Vincamine didn't exhibited in comparison with standard drugs (galanthamine IC50 AChE: 1,710 ± 0,065 µM, IC50 BChE: 42,30 ± 1,30 µM; huperzine A IC50 AChE: 0,033 ± 0,001 µM) any inhibition activity. On the other hand (+)-vincaminoreine exhibited fairly strong selective inhibition of BChE (IC50 = 8,71 ± 0,49 µM) with no inhibition of AChE. Key words: Vinca minor L., indole alkaloids, vincamine, vincaminoreine, Alzheimer disease,...
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