ORGANIC CHEMISTRY OF NATURAL PRODUCTS

Author: LEON OYOLA JUAN FRANCISCO.
Year: 2004.
University: LA LAGUNA.
Place of defense: INST. UNIVERSITARIO DE BIOORGANICA ANTONIO GLEZ.
Place of preparation: INST. UNIVERSITARIO DE BIOORGANICA ANTONIO GLEZ.

Summary: In this Doctoral Thesis is the isolation and structural determination of the secondary metabolites found in six species of fungi basidiomicetos belonging to four different genres (Ganoderma, Laetiporus, Suillus, Trametes), which were collected in different regions of Colombia. So, Ganoderma lucidum identifies eleven substances: six sterols type ergostano and five triterpenes type of lanosterol, being two of them new compounds in the scientific literature. In Ganoderma concinna are isolated fifteen substances: three sterols type ergostano and twelve triterpenes type of lanosterol finding that three of them were found to be new in the bibliography. From Ganoderma australe could be isolated and identified nine substances: three sterols type ergostano and six triterpenes type lanosterol being two of them new in the scientific literature. In laetiporus sulphureus are isolated seven substances: a isoprenoide two sterols and five triterpenes, one of them again. In Suillus luteus eleven substances have been isolated, three aromatic compounds, a glicérido six sterols and for the first time in this genre a ceramide who was unprecedented in the literature. From Trametes menziesii identified five substances: a fatty acid, four sterols, and the first of its kind, two ceramides, one with a pattern of hydroxylation again. Because of the recognized biological potential of ceramides synthesis was performed total of two ceramides with a new model hidroxiloción in carbons 2 and 3 of the fatty acid which this is the first example of synthesis for this kind of ceramides. We evaluated the cytotoxicity of some of the triterpenes versus myeloid cells isolated from human leukemia HL-60 finding some cytotoxic activity, and also determines that any of these compounds induced apoptosis (programmed cell death) by activation of caspase-3 and liberation mitochondrial cytochrome c.

Author: GONZALEZ MARRERO JOAQUIN.
Year: 2004.
University: LA LAGUNA.
Place of defense: INST. UNIVERSITARIO DE BIOORGANICA ANTONIO GLEZ.
Place of preparation: INST. UNIVERSITARIO DE BIOORGANICA ANTONIO GLEZ.

Summary: The thesis includes the study of natural products in various aspects, such as isolation and structural elucidation of secondary metabolites isolated from the flowers of Salvia L. canariensis Cultivated semisíntesis of diterpenos abietánicos isolated gender sage and an approach to the synthesis of these compounds diterpenos from commercial, as well as the study of possible biological activities of the proceeds. The first part is an introduction to natural products and their application in pharmacology from below to focus on the products isolated from different species of the genus Salvia. In the chapter devoted to the study of the phytochemical flowers Salvia canariensis, described the isolation of many compounds, all of them previously isolated from other species of salvias. It prepared the 7-metoxi-epirosmanol by chemical transformations made from rosmanol. In addition, these reactions were also the 7-metoxirosmanol, 7-metoxirosmaquinona and metilen sagequinona A. For the development of the goals outlined in the summary part of diterpenos abietatánicos, is a methodology for the rapid and simple isolation of carnosol, main secondary metabolite isolated from the extracts of sage canariensis. Over the chapter develops a general methodology for transforming the carnosol in different derivatives at C-7's rosmanol. It is also preparing several compounds related to the group of tanshinonas, using as a starting material the 16-hidroxicarnosol. But perhaps the main contribution of this chapter is to develop reactions degradation ring bencénico of diterpenos abietatriénicos. In terms of total synthesis, the chapter begins with an introduction to various approaches synthetic, made previously by other research groups, to different diterpenos abietatriénicos. The following describes the results of an approximation to the total synthesis of ferruginol. Finally is the study of biological following activities: inhibition test escualeno synthase activity antioxidant, antimicrobial activity, activity citostática, enzymatic inhibition studies, the search for compounds anti-mitóticos and search for compounds inhibitors of protein synthesis.

Author: CEBALLOS CHIARUCCI PLACIDO A.
Year: 2004.
University: AUTÓNOMA DE MADRID.
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: QUÍMICA ORGÁNICA.

Summary: Summaries of various derivatives with substructure of tetrahidroisoquinolina and approach to the synthesis of natural products wailupemicina and fluostatina.

Author: BOLUDA CABRERA CARLOS JOSE.
Year: 2004.
University: LA LAGUNA.
Place of defense: INSTITUTO UNIVERSITARIO DE BIORGANICA ANTONIO GONZALES.
Place of preparation: INSTITUTO UNIVESITARIO DE BIORGANICA ANTONIO GONZALES.

Summary: There has been a review of the literature lignanos including their types, metabolism, physiological functions and biological activities. There were isolated 9 compounds known Bupleurun handiense and 5 justice hyssopifolia, both endemic to the Canary Islands. Also seha isolated and characterized a new lignado of Justice hyssopifolia, whom we called Justicidona and that so far is the only one that also has a system quinónico. We have carried out various approaches to the total synthesis of justicidona that have revealed the existence of certain difficulties in using the standard methods of synthesis for lignanos arilnaftelénicos. It has designed a synthetic strategy to solve the problems encountered that has brought out the total synthesis of justifying in 8 stages, through a linear sequence of reaccines well conocidad. It has carried out an experiment to study the difficulty encountered in the ciclación one of the presursores sintétivos of justicidona. This experiment was also an opportunity to carry out the total synthesis of justicidina E in 6 stages. Moreover, seha carried out semisíntesis of justicidona and other lignano which also involved a systems quinónico. It has carried out the acetylation enzyme regioselectiva of secoiridoides isolated Jadminum odoratisimun using the Candinda antarctica lipase, and have thus obtained new products difíciloes synthesis by conventional synthetic methods. Finally, we assessed the activity antilesihamni and citotoxica of natural and synthetic compounds obtained. Justicidona and some of its synthetic precursors have showed cytotoxic activity and antileshmania.

Author: GUTIÉRREZ GUEVARA MARCELINO.
Year: 2005.
University: SANTIAGO DE COMPOSTELA.
Place of defense: FACULTAD DE QUÍMICA.
Place of preparation: FACULTAD DE QUÍMICA.

Summary: This thesis describes the isolation, identification estructral and pharmacological activity of a number of natural products isolated from sponges Aplysina chiriquiensis and Aplysina gerardogreeni and the octocorals Leptogorgia dawn, Leptogorgia rigid and Muricea astera, collected in the Parqe National Coiba, located in Pacific Panama. The structural determination of the metabolites isolated and the absolute configuration of the new compounds is carried out through the full use of nuclear magnetic resonance, mass spectrometry, diffraction rayos-Xy dicrísmo circular. It has been synthesized and evalúado activity antiprotozoaria a series of analogs of the natural products isolated. . The crude extracts sponges Aplysina chiriquiensis and a. Gerardogreeni showed a potent inhibitory effect on the growth of marine bacteria and pathogenic Vibrio anguillarum activity antiprotozoaria against Plasmodium falciparum resistant to chloroquine. The fractionation of A. Chiriquiensis led by bioassay led to the isolation of five dibromotirosinas. Comparisons HPLC indicated that both sponges have a chemical composition similar, albeit with variations in the proportion of the metabolites. The aeroplysinin-1 was found as the active ingredient responsible for the potent antibacterial activity obseNada in crude extracts of both sponges, and the activity antiprotozoaria against Plasmodium falciparum and Trypanosoma cruzi. Of the gorgonians L. Dawn and L. Rigid were isolated diterpenos seven. It describes for the first time the structure of the leptolida. It has been assigned the absolute configuration of the seven diterpenos through diffraction of X-Rays, circular dichroism, and the correlation of the results obtained here with chemical transformations described in the literature. It describes for the first time the activity of the seven antimalárica diterpenos isolated. In extracts of octocoral M. Austere were isolated and identified nine natural products of which three are sesquiterpenos three are saponins and three are derived from tyramine. The three saponins and two derivatives of tyramine are new natural products. One of the saponins isolated is the first example described in the literature of a natural product with a non-polymer unit L-galactosa. It has developed a CD-based procedure for determining the absolute configuration of the sugars in a saponin intact. Its feasibility is demonstrated by several examples. We assessed the activity antiprotozoaria of natural products that have proven to be isolated assets in the range of concentrations ng / mL. The activity of saponins and the tiramidas compared with a range of synthetic analogues to assess the potential of these compounds as seed versus P. Falciparum.

Author: GARCÍA MUÑOZ SERGIO.
Year: 2005.
University: ALMERÍA.
Place of defense: F.DE CIENCIAS EXPERIMENTALES.
Place of preparation: FACULTAD DE CIENCIAS EXPERIMENTALES.

Summary: This is part Doctoral Thesis in the field of Organic Chemistry of Natural Products, in particular within the synthesis of biologically active molecules. The growing number of natural substances that are continually discovering, and the structural complexity of the same, makes it necessary to design new synthesis methods that facilitate the preparation of those molecules that are of interest, either by their biological and pharmacological properties . This research work reflects the development of two new synthetic strategies aimed at preparing neolignanos dihidrobenzo [b] furánicos, which are naturally occurring substances belonging to the family of lignanos. They are formed due to the oxidative coupling of fenilpropanos during the biosynthesis of lignin in plants and possess biological properties that have made their synthesis is a topic of growing interest, which has resulted in a large number of published papers on the matter. The strategies studied in this thesis has been based on two transformations great potential and versatility: the addition of benzoxasilepinas to benzaldehídos, known as the reaction Sakurai-Hosomi amended and the insertion intramolecular of carbenoides of rhodium.

Author: MESA SIVERIO DULCE JAZMIN.
Year: 2005.
University: LA LAGUNA.
Place of defense: IUBO ANTONIO GONZÁLEZ.
Place of preparation: IUBO ANTONIO GONZALEZ.

Summary: The thesis includes insulation, structural elucidation and preparation of derivatives of secondary metabolites isolated three plant species. It also includes the study of biological products and derivatives isolated and a study modeling, in order to consolidate and streamline the search for bioactive substances.