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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Biotransformation of monoterpenes and their chlorination products

Misra, Girish 05 1900 (has links)
No description available.
2

Structure and chemistry of flavour precursors in grapes /

Strauss, Christopher R. Unknown Date (has links) (PDF)
Thesis (Ph. D.)--Dept. of Organic Chemistry, University of Adelaide, 1983. / 8 leaves of plates in pocket. Includes bibliographical references (leaves 148-154).
3

Unraveling the regulation of mint monoterpene biosynthesis development and experimental testing of kinetic mathematical models /

Rios-Estepa, Rigoberto, January 2008 (has links) (PDF)
Thesis (Ph. D.)--Washington State University, December 2008. / Title from PDF title page (viewed on Jan. 15, 2009). "The Gene and Linda Voiland School of Chemical Engineering and Bioengineering." Includes bibliographical references.
4

Synthetic studies toward a total synthesis of paeoniflorigenin

Hong, Zhenqiu 16 July 1998 (has links)
Graduation date: 1999
5

The terpenes of Virginia pine (<u>Pinus virginiana mill</u>.), with investigations of their attractancy to the southern pine beetle (<u>Dendroctonus frontalis</u> zimm.)

Lewis, Kenneth Ronald 13 February 2009 (has links)
A gas chromatograph, equipped with a flame ionization detector, was used to qualitatively and quantitatively analyze the monoterpenes of Virginia pine. The instrument was adjusted for optimum performance prior to sample analysis. Two packed columns with stationary phases of different polarity, Carbowax 20M and polyphenyl ether + Igepal + Versamid-9JO, were used predominantly for analytical determinations. However, a S.C.O.T. column coated with UCON LB550X stationary phase, was used for measuring some compounds. The monoterpenes of Virginia pines were analyzed from foliage, phloem, and bark distillates, pentane extracts of xylem resin and beetle pitch tubes, and foliage and tree-bole vapors. Qualitative determinations were made by comparing relative retention time with known chemicals and mixtures of chemicals, and by introducing these standards into the sample. Quantitative determinations were based on normalization of peak areas for the known components. Peak areas measured with a disc integrator for liquid samples, and with a planimeter for vapor samples. / Ph. D.
6

Molecular imprinting of small, poorly functionalised organic compounds

Kueh, Alona Swee Hua. January 2008 (has links)
Thesis (M.Sc. Chemistry)--University of Waikato, 2008. / Title from PDF cover (viewed August 26, 2008) Includes bibliographical references (p. 160-168)
7

The asymmetric total synthesis of (+)-geniposide via phosphine-catalyzed (3+2) cycloaddition

Jones, Regan Andrew, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2009. / Title from PDF title page (University of Texas Digital Repository, viewed on Aug. 6, 2009). Vita. Includes bibliographical references.
8

Efeitos do Ãleo essencial do Eucalyptus tereticornis e dos constituintes 1,8-cineol, &#945;-pineno e &#946;-pineno na motilidade do mÃsculo liso gastrintestinal de ratos

Davi Matthews Jucà 26 September 2012 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O 1,8-cineol, o &#945;-pineno e &#946;-pineno sÃo monoterpenos constituintes do Ãleo essencial de plantas encontradas no Nordeste do Brasil como a âmalva-santaâ e o âeucaliptoâ (Ãleo Essencial do Eucalyptus tereticornis - OEET) que, na medicina popular, sÃo usadas no tratamento de distÃrbios intestinais e respiratÃrios. As aÃÃes miorrelaxantes desses Ãleos essenciais sÃo atribuÃdas à presenÃa desses monoterpenos. Nosso objetivo foi estudar mais detalhadamente os efeitos desses constituintes, assim como o do OEET, sobre a contratilidade do mÃsculo liso gastrintestinal e sobre o efeito procinÃtico em ratos. No presente estudo, foram usados ratos Wistar machos (180-250g) sacrificados por deslocamento cervical. Tiras de duodeno, Ãleo e fundo de estÃmago foram cortados e mantidos em soluÃÃo de Tyrode normal. As contraÃÃes isomÃtricas foram registradas atravÃs de transdutores de forÃa conectados a sistema computadorizado. SoluÃÃes contendo o 1,8-cineol, o &#945;-pineno ou &#946;-pineno foram preparadas em Tween 80 (concentraÃÃo final &#8804; 0,2% v/v). Usados isoladamente, o OEET, o 1,8-cineol, o &#945;-pineno e &#946;-pineno diminuÃram o tÃnus basal em tiras de duodeno. Em tÃnus basal de tiras isoladas de fundo gÃstrico, o OEET e o 1,8-cineol possuÃram efeito miorrelaxante, enquanto o &#945;-pineno e o &#946;-pineno possuÃram efeito contrÃtil. Esse efeito contrÃtil do &#945;-pineno e do &#946;-pineno em tiras isoladas de fundo gÃstrico à por possÃvel interferÃncia com o mecanismo dependente de IP3 e independe da ativaÃÃo local do receptor muscarÃnico e de uma aÃÃo central na ativaÃÃo de receptores nicotÃnicos, da mesma forma, o efeito miorrelaxante na musculatura lisa duodenal à mediado por possÃvel interferÃncia com os mecanismos celulares mediados pela formaÃÃo de IP3. AlÃm disso, como demonstrado anteriormente, em Ãleo de rato, esses monoterpenos provavelmente ativam as vias de entrada de Ca2+ para a cÃlula em situaÃÃes de depleÃÃo dos estoques intracelulares. Em estudos de retenÃÃo fracional de corante no trato gastrintestinal, o OEET, o 1,8-cineol, o &#945;-pineno e o &#946;-pineno promoveram a aceleraÃÃo do esvaziamento gÃstrico. O &#945;-pineno e &#946;-pineno tambÃm aceleraram o trÃnsito intestinal e reduziram a complacÃncia gÃstrica. Os nossos dados mostram que OEET possui propriedades prÃ-cinÃticas, que podem ser atribuÃveis aos efeitos contrastantes induzidos por &#945;-pineno e &#946;-pineno, corroborando com dados apresentados anteriormente (JucÃ, 2007). / The monoterpenes 1,8-cineole, &#945;-pinen and &#946;-pinene are constituents commonly found in several essential oils obtained from plants in Brazilian northeast such as âmalva-santaâ and âeucaliptoâ (Essential Oil of Eucalyptus tereticornis - EOET), which are used in folk medicine to treat respiratory and gastrointestinal dysfunctions. Myorelaxant actions are due to the presence of these constituents in their essential oils. The present work aimed to further study the pharmacological effects of these compounds, as well as the EOET, on smooth muscle gastrointestinal contractility and the prokinetic effect in rats. Wistar rats (200-250 g) were used, sacrificed by cervical dislocation. Strips were carefully obtained from gastric fundus, duodenum and ileum, and were maintained in normal Tyrode&#8223;s solution. Isometric contractions were recorded through force transducers coupled to a computerized data acquisition system. Solutions containing 1,8-cineolo, &#945;-pinene or &#946;-pinene were prepared with Tween 80 (final concentration &#8804; 0,2% v/v). Solely used, EOET, 1,8-cineole, &#945;-pinene or &#946;-pinene decreased duodenal basal tonus. In basal tone of gastric fundus isolated strips, EOET and 1,8-cineole had relaxant effect, while &#945;-pinene and &#946;-pinene had contractile effect. This contractile effect of &#945;-pinene and &#946;-pinene in isolated strips of gastric fundus is due to possible interference with IP3-dependent mechanism and independent of the muscarinic receptor activation and a central action in the activation of nicotinic receptors, in the same way, the duodenal smooth muscle relaxant effect is mediated by possible interference with the cellular mechanisms mediated by the formation of IP3. Moreover, as shown above, in the rat ileum, monoterpenes activate capacitative Ca2+ entry to intracellular milieu after Ca2+ stores depletion. The &#945;-pinene and &#946;-pinene also accelerated intestinal transit and reduced gastric compliance. Our data show that OEET has prokinetic properties in rats, which may be attributable to the contrasting effects induced by &#945;-pinene and &#946;-pinene, corroborating data presented previously (JucÃ, 2007).
9

Antimicrobial discovery from South African marine algae

Rufaro Mabande, Edmund January 2018 (has links)
>Magister Scientiae - MSc / Antimicrobials are chemical compounds that destroy or inhibit the growth of microorganisms. The majority of these antimicrobials are actually natural products or natural product derived with key examples being the pioneer antibiotics penicillin and cephalosporin. Antimicrobials are an extremely important class of therapeutic agents; however, the development of drug resistance and slow pace of new antibiotic discovery is one of the major health issues facing the world today. There is therefore a crucial need to discover and develop new antibacterial agents. In this study, the potential of marine algae as a source of new antibiotics was explored. Crude organic extracts and chromatographic fractions obtained from small-scale extraction of 17 different marine algae were used to prepare a pre-fractionated library that would be tested against several disease causing microorganisms. The activity of the pre-fractionated library and purified compounds was determined against a panel of drug resistant microorganisms namely Acinetobacter baumannii ATCCBAA®-1605™, Enterococcus faecalis ATCC® 51299™, Escherichia coli ATCC® 25922™, Staphylococcus aureus subsp. aureus ATCC® 33591™ and Candida albicans ATCC® 24433™. Finally, cytotoxicity tests of 50 selected library extracts and isolated compounds were done against two cell lines namely MCF-7 (breast cancer) and HEK-293 (kidney embryonic).
10

Factors influencing halogenated monoterpene production in microplantlets derived from the red macroalga Ochtodes secundiramea

Polzin, Jason 28 April 2005 (has links)
Halogenated monoterpene production by the red macroalga Octhodes secundiramea was studied-under different levels of nutrient, bromide, vanadium and light delivery. The key products formed were identified as myrcene, betaelemene, the Z and E isomers of l0-bromomyrcene, 3-chloro-10E-bromomyrcene, Apakaocthodene A, and isomers of chloromyrcene and dibromomyrcene. The proposed pathway begins with an initial halogenation of myrcene to 3- chloromyrcene or 10-bromomyrcene. 10-bromomyrcene reacts with either chloride or bromide ions producing either 3-chloro-10E-bromomyrcene or 1,10- dibromomyrcene. The production of Apakaochtodene A starts from myrcene with 4 consecutive halogenation reactions, the first one forming the cyclic ring. All fermentations were carried out in similar 2L photobioreactors. Temperature was controlled at 26°C, with a photoperiod of 14 hours on:10 hours off. Incident light intensity was 143 μE m⁻² s⁻¹ for nutrient, bromide and vanadium delivery cultivations and the mean light intensity was set to 52.5, 125, and 240 μE m⁻² s⁻¹ for light delivery cultivations. The pH was buffered to 8.0 with sodium bicarbonate, but not controlled. Air was supplied at 630 mL min⁻¹, vvm of 0.3, and CO₂ was supplied at 2 mL min⁻¹ for nutrient and light delivery cultivations and 0 mL min⁻¹ for bromide and vanadium delivery cultivations. For nutrient delivery cultivations, nitrate was delivered at 0.006, 0.076 and 0.74 mmol Nitrate L⁻¹ day⁻¹ and phosphate was delivered at 0.33, 3.99 and 38.4 μmol Phosphate L⁻¹ day⁻¹. For semi-continuous delivery cultivations, bromide was delivered at 0.0, 0.0074, 0.013 and 0.13 mmol Bromide L⁻¹ day⁻¹ at a constant vanadium delivery of 6.38 to 7.35 nmol Vanadium L⁻¹ day⁻¹, and vanadium delivery was set to 0.0 and 6.38 nmol Vanadium L⁻¹ day⁻' at a constant bromide delivery of 0.13 mmol Bromide L⁻¹ day⁻¹. For fed-batch bromide and vanadium delivery cultivations the one time pulse of bromide raised the medium bromide concentration to 0.0, 0.038, 0.128 and 1.4 mmol Bromide L⁻¹, with the vanadium concentration going to 416 to 520 nmol Vandadium L⁻¹, and the pulse of vanadium raised the medium vanadium concentration to 0.0 and 515 mmol Vanadium L⁻¹, with the bromide concentration going to 1.1 to 1.4 mmol Bromide L⁻¹. / Graduation date: 2005

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