Síntese e caracterização de cloro[ácido 2-(difenilfosfino)benzóico]-ouro(I) e alguns de seus derivados

In this contribution a few new gold(I)phosphine complexes, [2-(PPh2)C6H4CO 2H]AuX (where X = Cl, SCN, Br3) and a similar gold(III) derivative [{2-(PPh2)C6H4CO 2H}AuIII Cl (C6H4CH2NMe2 )]Cl have been synthesised and characterised. The phosphine, 2-(diphenylphosphino)benzoic acid, has been employed for the first time in gold chemistry. This ligand is potentially bidentate through bonding of the phosphine and carboxylate groups. The X-ray structure of the complex chloro[2-(diphenylphosphino) benzoic acid]gold(I) has been elucidated and the bond lengths encountered show great similarity to those of chloro(triphenylphosphine)gold(I). [2-(PPh2)C6H4CO 2H]AuCl crystallises in the space group P2(1)/c with a = 9.113(2) Å, b = 10.925(2) Å, c = 23.069(4) Å, beta = 99.95º(3), V = 2299 ų, Z = 4 and R = 0.091. Biological tests for anti-fungal and anti-bacterial activity demostrate that [2-(PPh2)C6H4CO 2H]AuCl exhibits broad spectrum activity against a range of organisms.

Novos derivados do sistema heterocíclico 1H-pirazolo[3,4-b]piridina: síntese e assinalamentos de hidrogênios e carbonos por RMN 1D e 2D

The synthesis and NMR analysis of seven new 4-(aryl)amino-5-carboethoxy-1,3-dimethyl-1H-pyrazolo[3,4- b]pyridines (7-13) are described. The synthetic approach used involved the preparation of intermediates 5-aminopyrazol (4), the enamine derivative (5) and the 4-chloro-1H-pyrazolo[3,4-b]pyridine (6). Compounds (7-13) were obtained by treatment of 6 with the desired aniline. The structures of new heterocyclic compounds and their precursors intermediates were assigned on the basis of spectral analysis including 1D and 2D NMR experiments [¹H; 13C{¹H} and DEPT; ¹H x ¹H - COSY; ¹H x13C - COSY, nJ CH, n = 1, 2 or 3 (HETECOR and COLOC)].

Spectrophotometric determination of cefaclor in pharmaceutical preparations

A simple spectrophotometric method is proposed for the determination of cefaclor. The method involves alkaline hydrolysis of the drug in ammonia buffer solution at pH 10 to yield diketopiperazine-2,5-dione derivative and subsequent measurement at 340 nm. Beer's law is obeyed in the concentration range 1.8 - 55 mg/mL. The proposed method was successfully applied to the determination of cefaclor in pharmaceutical formulations.

Reduction and Analysis Methods of Indigo

Throughout history indigo was derived from various plants for example Dyer’s Woad (Isatis tinctoria L.) in Europe. In the 19th century were the synthetic dyes developed and nowadays indigo is mainly synthesized from by-products of fossil fuels. Indigo is a so-called vat dye, which means that it needs to be reduced to its water soluble leucoform before dyeing. Nowadays, most of the industrial reduction is performed chemically by sodium dithionite. However, this is considered environmentally unfavourable because of waste waters contaminating degradation products. Therefore there has been interest to find new possibilities to reduce indigo. Possible alternatives for the application of dithionite as the reducing agent are biologically induced reduction and electrochemical reduction. Glucose and other reducing sugars have recently been suggested as possible environmentally friendly alternatives as reducing agents for sulphur dyes and there have also been interest in using glucose to reduce indigo. In spite of the development of several types of processes, very little is known about the mechanism and kinetics associated with the reduction of indigo. This study aims at investigating the reduction and electrochemical analysis methods of indigo and give insight on the reduction mechanism of indigo. Anthraquinone as well as it’s derivative 1,8-dihydroxyanthraquinone were discovered to act as catalysts for the glucose induced reduction of indigo. Anthraquinone introduces a strong catalytic effect which is explained by invoking a molecular “wedge effect” during co-intercalation of Na+ and anthraquinone into the layered indigo crystal. The study includes also research on the extraction of plant-derived indigo from woad and the examination of the effect of this method to the yield and purity of indigo. The purity has been conventionally studied spectrophotometrically and a new hydrodynamic electrode system is introduced in this study. A vibrating probe is used in following electrochemically the leuco-indigo formation with glucose as a reducing agent.

Constituintes químicos das raízes de Pyrostegia Venusta e considerações sobre a sua importância medicinal

This paper describes the chemical constituents isolated from roots of Pyrostegia venusta. From ethanol extract of the roots allantoin, beta-sitosterol, 3b-O-beta-D-glupyranosylsitosterol and hesperedin were isolated. The structures of these natural products were identified on the basis of spectral data, including 2D NMR of the peracetyl derivative of hesperidin.

An update on EMU sovereign yield spread drivers in times of crisis: A panel data analysis

We empirically investigate the determinants of EMU sovereign bond yield spreads with respect to the German bund. Using panel data techniques, we examine the role of a wide set of potential drivers. To our knowledge, this paper presents one of the most exhaustive compilations of the variables used in the literature to study the behaviour of sovereign yield spreads and, in particular, to gauge the effect on these spreads of changes in market sentiment and risk aversion. We use a sample of both central and peripheral countries from January 1999 to December 2012 and assess whether there were significant changes after the outbreak of the euro area debt crisis. Our results suggest that the rise in sovereign risk in central countries can only be partially explained by the evolution of local macroeconomic variables in those countries.

An update on EMU sovereign yield spread drivers in times of crisis: A panel data analysis

We empirically investigate the determinants of EMU sovereign bond yield spreads with respect to the German bund. Using panel data techniques, we examine the role of a wide set of potential drivers. To our knowledge, this paper presents one of the most exhaustive compilations of the variables used in the literature to study the behaviour of sovereign yield spreads and, in particular, to gauge the effect on these spreads of changes in market sentiment and risk aversion. We use a sample of both central and peripheral countries from January 1999 to December 2012 and assess whether there were significant changes after the outbreak of the euro area debt crisis. Our results suggest that the rise in sovereign risk in central countries can only be partially explained by the evolution of local macroeconomic variables in those countries.

Inhibition of nociceptive responses after systemic administration of amidated kyotorphin

BACKGROUND AND PURPOSE Kyotorphin (KTP; L-Tyr-L-Arg), an endogenous neuropeptide, is potently analgesic when delivered directly to the central nervous system. Its weak analgesic effects after systemic administration have been explained by inability to cross the blood-brain barrier (BBB) and detract from the possible clinical use of KTP as an analgesic. In this study, we aimed to increase the lipophilicity of KTP by amidation and to evaluate the analgesic efficacy of a new KTP derivative (KTP-amide - KTP-NH 2). EXPERIMENTAL APPROACH We synthesized KTP-NH 2. This peptide was given systemically to assess its ability to cross the BBB. A wide range of pain models, including acute, sustained and chronic inflammatory and neuropathic pain, were used to characterize analgesic efficacies of KTP-NH 2. Binding to opioid receptors and toxicity were also measured. KEY RESULTS KTP-NH 2, unlike its precursor KTP, was lipophilic and highly analgesic following systemic administration in several acute and chronic pain models, without inducing toxic effects or affecting motor responses and blood pressure. Binding to opioid receptors was minimal. KTP-NH 2 inhibited nociceptive responses of spinal neurons. Its analgesic effects were prevented by intrathecal or i.p. administration of naloxone. CONCLUSIONS AND IMPLICATIONS Amidation allowed KTP to show good analgesic ability after systemic delivery in acute and chronic pain models. The indirect opioid-mediated actions of KTP-NH 2 may explain why this compound retained its analgesic effects although the usual side effects of opioids were absent, which is a desired feature in next-generation pain medications

Arvopaperistaminen ja luottojohdannaiset luottoriskin ja omien varojen hallinnan välineenä

Tässä tutkimuksessa selvitetään, voisiko Pohjola Pankki tehostaa omien varojen käyttöään ja luoda taloudellista lisäarvoa osakkeenomistajilleen hyödyntämällä arvopaperistamista tai luottojohdannaisia rahoitustaseen yritys-lainasaamisiin sisältyvän luottoriskin hallintaan. Työssä pohditaan myös ko. instrumenttien soveltuvuutta ja transaktion toteutusprosessia Pohjola Pankin näkökulmasta. Tutkimus on empiirinen tapaustutkimus, jossa on hyödynnetty kvantitatiivista tutkimusmetodia. Tulosten valossa Pohjola Pankki pystyy alentamaan omien varojen määrä luomaan lisäarvoa ja parantamaan riskipainotettua kannattavuuttaan arvopaperistamalla yrityslainasaataviaan tai ostamalla luottojohdannaisen. Huomioiden kohdeyrityksen luottoportfolion rakenteen ja transaktion toteuttamiseen vaadittavat toimenpiteet, soveltuu luottojohdannainen arvopaperistamista paremmin luottoriskin johtamiseen kohdeyrityksessä – edellyttäen, että suojaus-kustannukset eivät nouse liian korkeiksi ja vapautuvat omat varat saadaan hyödynnettyä mahdollisimman tehokkaasti.

Sobre a primeira lei da termodinâmica

Entropy is a concept that has long stimulated human curiosity, resulting in an huge intelectual production. The same has not occurred for the first law of thermodynamics, perhaps because of its apparent obviousness. In this article the first law presentation, as displayed in most traditional physical chemistry textbooks, is criticized. An alternative view is suggested, in accordance with temporal thermodynamics. The time derivative local form of the second law is used to stress the entropy concept implications on the notion of internal energy.

Perfil cromatográfico de duas espécies de Plumbaginaceae: Plumbago scandens L. E Plumbago auriculata Lam

The genus Plumbago belongs to the family Plumbaginaceae, order Plumbaginales. Comparative chemical profile of P. scandens (native) and P. auriculata (cultivated) was obtained by normal and reversed-phase high performance liquid chromatography with photodiode array detector. Comparison of the ultraviolet espectra and the retention times for the compounds allowed to find similar metabolic patterns in roots, stems and leaves. Four flavonoids, one phenolic acid or derivative and the naphtoquinone plumbagin were comparatively identified to standards.

Terapia fotodinâmica: aspectos farmacológicos, aplicações e avanços recentes no desenvolvimento de medicamentos

Photodynamic Therapy (PDT) is a clinical procedure, which utilize a photosensitive compound and light. This is a new modality of treatment for cancer, aged related macular degenerescence (AMD), psoriasis, arthritis, arterial restenosis, etc which exhibits efficiency, less traumatic effects, low recovery time and few co-lateral effects. The first officially approved drug for PDT by the Food and Drug Administration (EUA) is Photofrinâ, which is applied for cancer. A new generation drug for PDT, Visudyneâ was recently approved to treat AMD; its photoactive compound is BPDMA, a benzoporphyrin mono-acid derivative (chlorin-type molecule). A concise history, technical information and some drugs for PDT are reported.

Estratégia de simplificação molecular no planejamento racional de fármacos: a descoberta de novo agente cardioativo

In this article are described examples of the successful use of molecular simplification strategy in the discovery of new drugs from bioactive natural products and synthetic compounds. The discovery of a new cardiotonic derivative (37, 2-thienylidene-3,4-methylenedioxybenzoylhydrazine; LASSBio-294), efficiently synthesized from Brazilian natural product and structurally designed by molecular simplification of active pyridazinone compounds reported in the literature, is described. A brief description of the pharmacological profile of this new cardiotonic lead-compound, belonging to the N-acylhydrazone (NAH) class, is also reported herein.

A synthetic approach to palmerolides via Negishi cross coupling. The challenge of the C15-C16 bond formation

The esterification of fragment C1-C8 (2) with fragment C16-C23 (3) to give iodo derivative 4, followed by a Pd-catalysed coupling with a C9-C15 fragment (7 or 8), may provide a common precursor of most palmerolides. Ligands and reaction conditions were exhaustively examined to perform the C15-C16 bond formation via Negishi reaction. With simple models, pre-activated Pd-Xantphos and Pd-DPEphos complexes were the most efficient catalysts at RT. Zincation of the C9-C15 fragment (8) and cross coupling with 4 required 3 equiv of t-BuLi, 10 mol % of Pd-Xantphos and 60 °C.

O efeito da granulometria na decrepitação durante a decomposição térmica de calcários e carvão

The use of fluidized bed combustors to burn coal is largely studied to permit the addition of limestone to capture SO2. The particle size for coal and limestone is an important parameter in this process. Thermogravimetry (TG) is used to elucidate the combustion and sulfation processes, but the experimental parameters must be evaluated to be representative in fluidized bed combustors. In the present study the effect of particle size is analyzed in the calcination of limestones and the combustion of coal through the thermogravimetric curve for limestone and derivative thermogravimetric curve for coal. Small peaks representing mass losses between 400 and 500 ºC are observed due to the jumping of particles out of the crucible. This effect, recognized as decrepitation is observed for mid-sized particles provoked by the release of water vapor trapped within their lattice.