Main Polar Metabolites from Leaves of the Native Andean Species Jungia rugosa Less (Asteraceae)

The ethanolic extract of Jungia rugosa Less, a popular Andean species belonging to the family Asteraceae, was characterized chemically. The extract was deprived of chlorophyll by solid-phase extraction, using Diaion Hp-20 resin as solid phase, and eluting with a mixture of EtOH/H2O according to a decreasing polarity gradient. The chlorophyll-free extract was then repeatedly fractionated by open column chromatography in normal phase and preparative thin layer chromatography. Two main metabolites were finally purified and identified through structure elucidation. Nuclear magnetic resonance spectroscopy (NMR) and electrospray ionization-mass spectrometry (ESI-MS) were the 2 techniques used for analysis. The identified metabolites were coumarins: (1) umbelliferone and (2) coumarin-5- methyl-4α-glucoside. Compound 1 is known in the literature for having anti-inflammatory, antihyperglycemic, and antitumor activities. Compound 2 has not been described before for this botanical genus and its pharmacological effects are still uninvestigated. Keywords: Jungia rugosa, umbelliferone, coumarin-5-methyl-4-glucoside, NMR, ESI-MS, Ecuador. Resumen Se caracterizó químicamente el extracto etanólico de Jungia rugosa Less, una popular especie andina perteneciente a la familia Asteraceae. Se eliminó las clorofilas al extracto mediante extracción en fase sólida, utilizando como fase sólida resina de Diaion Hp-20 y eluyendo con una mezcla de EtOH/H2O según un gradiente de polaridad decreciente. El extracto libre de clorofila se fraccionó repetidamente mediante cromatografía en columna abierta en fase normal y cromatografía en capa fina preparativa. Finalmente, se purificaron e identificaron dos metabolitos principales mediante la elucidación de la estructura. Se utilizaron espectroscopía de resonancia magnética nuclear (RMN) y espectrometría de masas de ionización por aspersión de electrones (ESI-MS). Los metabolitos identificados fueron las cumarinas: umbeliferona (1) y cumarina-5-metil-4α-glucósido (2). El compuesto 1 es conocido en la literatura por tener actividad antiinflamatoria, antihiperglucémica y antitumoral. El compuesto 2 no se ha descrito antes para este género botánico y sus efectos farmacológicos aún no se han investigado. Palabras Clave: Jungia rugosa, umbeliferona, cumarina-5-metil-4-glucósido, RMN, ESI-MS, Ecuador

Semi-synthetic Derivatives of Limonin A: Synthesis Using Basic Hydrolysis and Reduction with NaBH4

Limonin A (L-A) was obtained from seeds of Citrus sinensis that were dried, grounded, and extracted using Soxhlet equipment. Initially, 100% hexane was used to eliminate fats, and finally, 100% dichloromethane was used in order to concentrate and isolate the compound. L-A recrystallization was performed using acetic acid. The purified fraction was identified as limonin according to spectral nuclear magnetic resonance (NMR) data. Two reactions were performed from L-A: Basic hydrolysis that acted on the A’ lactone ring producing a sodium salt of the lactone, and reduction with NaBH4 to reduce the carbonyl of carbon C-7 and generate the corresponding alcohol limonol. The structural modification of abundant secondary metabolites can become a source of new products with biological activity, useful in the pharmaceutical, cosmetic, and agrochemical industries of natural origin. Keywords: limonin, semisynthetic derivates, bioactive compounds, non-timber forest products. Resumen La limonina A (L-A) se obtuvo a partir de semillas de Citrus sinensis, que fueron secadas, molidas y extraídas en equipo Soxhlet, utilizando inicialmente hexano al 100% para eliminar grasas y finalmente diclorometano al 100% para concentrar y aislar el compuesto. La re cristalización de la L-A se realizó utilizando ácido acético. La fracción purificada se identificó como limonina, acorde a los datos espectrales de RMN (Resonancia Magnética Nuclear). A partir de la Limonina A se realizaron dos reacciones: Hidrólisis básica que actuó sobre el anillo de lactona A’ produciendo la sal sódica de lactona y reducción con NaBH4 para reducir el carbonilo del carbono C-7 y generar el correspondiente alcohol limonol. La modificación estructural de metabolitos secundarios abundantes puede convertirse en una fuente para generar nuevos productos con actividad biológica, útiles en las industrias farmacéutica, cosmética y agroquímica de origen natural. Palabras Clave: Limonina; derivados semisintéticos, compuestos bioactivos, productos forestales no maderables

Phase Rotation, Cooling And Acceleration Of Muon Beams: A Comparison Of Different Approaches

Experimental and theoretical activities are underway at CERN with the aim of examining the feasibility of a very-high-flux neutrino source. In the present scheme, a high-power proton beam (some 4 MW) bombards a target where pions are produced. The pions are collected and decay to muons under controlled optical condition. The muons are cooled and accelerated to a final energy of 50 GeV before being injected into a decay ring where they decay under well-defined conditions of energy and emittance. We present the most challenging parts of the whole scenario, the muon capture, the ionisation-cooling and the first stage of the muon acceleration. Different schemes, their performance and the technical challenges are compared.Comment: LINAC 2000 CONFERENCE, paper ID No. THC1

Beam Loss Monitors for Heavy Ion Operation

The performance of the LHC as a heavy-ion collider is expected to be limited by a variety of beam loss mechanisms that are non-existent, or substantially different, in the case of protons. Among these are ultra-peripheral interactions of the colliding beams and the collimation inefficiency. Loss patterns are different and require additional installations of beam loss monitors. Further, the relation between energy deposition in superconducting magnet coils and the loss monitor signals has to be reassessed for heavy ions in order to determine the thresholds for dumping beams

Monitoring heavy-ion beam losses in the LHC

The LHC beam loss monitor (BLM) system, primarily designed for proton operation, will survey particle losses and dump the beam if the loss rate exceeds a threshold expected to induce magnet quenches. Simulations of beam losses in the full magnet geometry allow us to compare the response of the BLMs to ion and proton losses and establish preliminary loss thresholds for quenches. Further simulations of beam losses caused by collimation and electromagnetic interactions peculiar to heavy ion collisions determine the positions of extra BLMs needed for ion operation in the LHC

A new sesquiterpene essential oil from the native andean species jungia rugosa less (Asteraceae): Chemical analysis, enantiomeric evaluation, and cholinergic activity

As part of a project devoted to the phytochemical study of Ecuadorian biodiversity, new essential oils are systematically distilled and analysed. In the present work, Jungia rugosa Less (Asteraceae) has been selected and some wild specimens collected to investigate the volatile fraction. The essential oil, obtained from fresh leaves, was analysed for the first time in the present study. The chemical composition was determined by gas chromatography, coupled to mass spectrometry (GC-MS) for qualitative analysis, and to flame ionization detector (GC-FID) for quantitation. The calculation of relative response factors (RRF), based on combustion enthalpy, was carried out for each quantified component. Fifty-six compounds were identified and quantified in a 5% phenyl-polydimethylsiloxane non-polar column and 53 compounds in a polyethylene glycol polar column, including four undetermined compounds. The main feature of this essential oil was the exclusive sesquiterpenes content, both hydrocarbons (74.7% and 80.4%) and oxygenated (8.3% and 9.6%). Major constituents were: γ-curcumene (47.1% and 49.7%) and β-sesquiphellandrene (17.0% and 17.9%), together with two abundant undetermined oxygenated sesquiterpenes, whose abundance was 6.7–7.2% and 4.7–3.3%, respectively. In addition, the essential oil was submitted to enantioselective evaluation in two β-cyclodextrin-based enantioselective columns, determining the enantiomeric purity of a minor component (1S,2R,6R,7R,8R)-(+)-α-copaene. Finally, the AChE inhibition activity of the EO was evaluated in vitro. In conclusion, this volatile fraction is suitable for further investigation, according to two main lines: (a) the purification and structure elucidation of the major undetermined compounds, (b) a bio-guided fractionation, intended to investigate the presence of new sesquiterpene AChE inhibitors among the minor components

Beam losses from ultra-peripheral nuclear collisions between Pb ions in the Large Hadron Collider and their alleviation

Electromagnetic interactions between colliding heavy ions at the Large Hadron Collider (LHC) at CERN will give rise to localized beam losses that may quench superconducting magnets, apart from contributing significantly to the luminosity decay. To quantify their impact on the operation of the collider, we have used a three-step simulation approach, which consists of optical tracking, a Monte-Carlo shower simulation and a thermal network model of the heat flow inside a magnet. We present simulation results for the case of Pb ion operation in the LHC, with focus on the ALICE interaction region, and show that the expected heat load during nominal Pb operation is 40% above the quench level. This limits the maximum achievable luminosity. Furthermore, we discuss methods of monitoring the losses and possible ways to alleviate their effect.Comment: 17 pages, 20 figure

Chemical, enantioselective, and sensory analysis of a cholinesterase inhibitor essential oil from coreopsis triloba S.F. Blake (asteraceae)

The fresh leaves of Coreopsis triloba S.F. Blake, collected at Cerro Villonaco in Loja, Ecuador, were investigated with respect to their essential oil (EO). The chemical composition was determined qualitatively through gas chromatography coupled with mass spectrometry (GC-MS) and quantitatively by gas chromatography coupled with flame ionization (GC-FID), using relative response factors (RRF) based on the enthalpy of combustion. The essential oil contained between 92.5% and 93.4% of monoterpene hydrocarbons, with (E)-β-ocimene being the main component (35.2–35.9%), followed by β-phellandrene (24.6–25.0%), α-pinene (15.3–15.9%), myrcene (10.9–11.0%), sabinene (2.2–2.4%), (Z)-β-ocimene (1.5%), and germacrene D (1.2–1.3%). The enantiomeric distribution of α-pinene, β-pinene, limonene, and germacrene D was also determined. The main components responsible for the aroma were identified through aroma extract dilution analysis (AEDA), a gas chromatography-olfactometry (GC-O) based technique, being α-pinene, β-pinene (0.6%), terpinolene (0.1%), α-copaene (0.1–0.3%), β-phellandrene, and (E)-4,8-dimethyl-1,3,7-nonatriene (0.1–0.2%) the main olfactory constituents according to the decreasing factor of dilution (FD) order. The biological tests showed IC50 inhibition values of 42.2 and 6.8 µg/mL for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), respectively