Showing papers in "Molecules in 2005"
TL;DR: This review discusses the conventional and recent technologies for microencapsulation of the drugs using biodegradable polymers, and presents characteristics and degradation behaviors of biode Gradient polymers which are currently used in drug delivery.
Abstract: Drug delivery has become increasingly important mainly due to the awareness of the difficulties associated with a variety of old and new drugs Of the many polymeric drug delivery systems, biodegradable polymers have been used widely as drug delivery systems because of their biocompatibility and biodegradability The majority of biodegradable polymers have been used in the form of microparticles, from which the incorporated drug is released to the environment in a controlled manner The factors responsible for controlling the drug release rate are physicochemical properties of drugs, degradation rate of polymers, and the morphology and size of microparticles This review discusses the conventional and recent technologies for microencapsulation of the drugs using biodegradable polymers In addition, this review presents characteristics and degradation behaviors of biodegradable polymers which are currently used in drug delivery
299 citations
TL;DR: Non-viral gene delivery vectors, termed "self-assembled" systems, and are based on cationic molecules, which form spontaneous complexes with negatively charged nucleic acids are described, with an emphasis on the obstacles to achieve successful transfection in vivo.
Abstract: Nucleic acid delivery has many applications in basic science, biotechnology, agriculture, and medicine. One of the main applications is DNA or RNA delivery for gene therapy purposes. Gene therapy, an approach for treatment or prevention of diseases associated with defective gene expression, involves the insertion of a therapeutic gene into cells, followed by expression and production of the required proteins. This approach enables replacement of damaged genes or expression inhibition of undesired genes. Following two decades of research, there are two major methods for delivery of genes. The first method, considered the dominant approach, utilizes viral vectors and is generally an efficient tool of transfection. Attempts, however, to resolve drawbacks related with viral vectors (e.g., high risk of mutagenicity, immunogenicity, low production yield, limited gene size, etc.), led to the development of an alternative method, which makes use of non-viral vectors. This review describes non-viral gene delivery vectors, termed "self-assembled" systems, and are based on cationic molecules, which form spontaneous complexes with negatively charged nucleic acids. It introduces the most important cationic polymers used for gene delivery. A transition from in vitro to in vivo gene delivery is also presented, with an emphasis on the obstacles to achieve successful transfection in vivo.
204 citations
TL;DR: The most common manufacturing methods for polymeric particles and the physiology of particle absorption from the gastrointestinal (GI) tract are reviewed and the use of polymeric particulate systems to improve the oral absorption of insulin is discussed.
Abstract: Oral administration remains the most convenient way of delivering drugs. Recent advances in biotechnology have produced highly potent new molecules such as peptides, proteins and nucleic acids. Due to their sensitivity to chemical and enzymatic hydrolysis as well as a poor cellular uptake, their oral bioavailability remains very low. Despite sophisticated new delivery systems, the development of a satisfactory oral formulation remains a challenge. Among the possible strategies to improve the absorption of drugs, micro- and nanoparticles represent an exciting approach to enhance the uptake and transport of orally administered molecules. Increasing attention has been paid to their potential use as carriers for peptide drugs for oral administration. This article reviews the most common manufacturing methods for polymeric particles and the physiology of particle absorption from the gastrointestinal (GI) tract. In a second part, the use of polymeric particulate systems to improve the oral absorption of insulin is discussed.
144 citations
TL;DR: A novelhydrogel obtained with this polysaccharide and borate ions is described, and the particular structure of this hydrogel network has been interpreted in terms of conformational analysis and molecular dynamics.
Abstract: Scleroglucan is a natural polysaccharide, produced by fungi of the genus Sclerotium, that has been extensively studied for various commercial applications (secondary oil recovery, ceramic glazes, food, paints, etc.) and also shows several interesting pharmacological properties. This review focuses its attention on the use of scleroglucan, and some derivatives, in the field of pharmaceutics and in particular for the formulation of modified-release dosage forms. The reported investigations refer mainly to the following topics: natural scleroglucan suitable for the preparation of sustained release tablets and ocular formulations; oxidized and crosslinked scleroglucan used as a matrix for dosage forms sensitive to environmental conditions; co-crosslinked scleroglucan/gellan whose delivery rate can be affected by calcium ions. Furthermore, a novel hydrogel obtained with this polysaccharide and borate ions is described, and the particular structure of this hydrogel network has been interpreted in terms of conformational analysis and molecular dynamics. Profound attention is devoted to the mechanisms involved in drug release from the tested dosage forms that depend, according to the specific preparation, on swelling and/or diffusion. Experimental data are also discussed on the basis of a mathematical approach that allows a better understanding of the behavior of the tested polymeric materials.
114 citations
TL;DR: Advantages and limitations of these types of DDS are discussed through representative examples of polymer-drugs and polymer-proteins conjugates recently developed.
Abstract: In this work, polymer-drugs conjugates used as drug delivery systems (DDS) are revised attending to their chemical conjugation. Namely, the classification of this type of DDS is based on the conjugation sites of the reactive groups (i.e., via end groups or pendant polymer groups). Advantages and limitations of these types of DDS are discussed through representative examples of polymer-drugs and polymer-proteins conjugates recently developed.
106 citations
TL;DR: A new yellow pigment has been isolated from the marine bacterium P. tunicata and identified as a new member of the tambjamine class of compounds.
Abstract: The marine environment is a major source for many novel natural compounds. A new yellow pigment has been isolated from the marine bacterium P. tunicata and identified as a new member of the tambjamine class of compounds. The structural identification was achieved by a combination of 1D and 2D-NMR spectroscopy and high resolution mass spectrometry data.
105 citations
TL;DR: S sulfur and nitrogen-containing heterocyclic compounds have maintained the interest of researchers through decades of historical development of organic synthesis as discussed by the authors, which led to the development of modern synthetic methods that are the subject of this special issue.
Abstract: For more than a century, heterocycles have constituted one the largest areas of research in organic chemistry. They have contributed to the development of society from a biological and industrial point of view as well as to the understanding of life processes and to the efforts to improve the quality of life. Heterocycles play an important role in biochemical processes because the side groups of the most typical and essential constituents of living cells, DNA and RNA, are based on aromatic heterocycles [1]. Among the approximately 20 million chemical compounds identified by the end of the second millennium, more than two-thirds are fully or partially aromatic, and approximately half are heterocyclic. The presence of heterocycles in all kinds of organic compounds of interest in biology, pharmacology, optics, electronics, material sciences, and so on is very well known. Between them, sulfur and nitrogen-containing heterocyclic compounds have maintained the interest of researchers through decades of historical development of organic synthesis. The grounds of this interest were their biological activities and unique structures that led to several applications in different areas of pharmaceutical and agrochemical research or, more recently, in material sciences [2]. The family of sulfur–nitrogen heterocycles includes highly stable aromatic compounds that display physicochemical properties with relevance in the design of new materials, especially those relating to molecular conductors and magnets. During the past few decades, interest has been rapidly growing in gaining insight into the properties and transformations of these heterocycles The interesting characteristics found in many of them have led to the development of modern synthetic methods that are the subject of this special issue. Nitrogen and sulfur organic aromatic heterocycles are formally derived from aromatic carbon cycles with a heteroatom taking the place of a ring carbon atom or a complete CH=CH group. The presence of heteroatoms results in significant changes in the cyclic molecular structure due to the availability of unshared pairs of electrons and the difference in electronegativity between heteroatoms and carbon. Therefore, nitrogen and sulfur heterocyclic
94 citations
TL;DR: The structures of the synthesized compounds were confirmed by elemental analyses, IR and 1H-NMR spectra, and their thiol-thione tautomeric equilibrium is described.
Abstract: 5-Furan-2-yl[1,3,4]oxadiazole-2-thiol (Ia) and 5-furan-2-yl-4H-[1,2,4]-triazole-3-thiol (Ib) were synthesized from furan-2-carboxylic acid hydrazide. Mannich bases and methyl derivatives were then prepared. The structures of the synthesized compounds were confirmed by elemental analyses, IR and (1)H-NMR spectra. Their thiol-thione tautomeric equilibrium is described.
75 citations
TL;DR: The adhesive potential of Gantrez nanoparticles fluorescently labeled with rhodamine B isothiocyanate was found to be stronger when folded as nanoparticles than in the solubilised form, and the adhesive capacity of nanoparticles, the intensity and the relative duration of the adhesive interactions within the gut as a function of the cross-linking degree.
Abstract: Bioadhesive nanoparticles have been proposed as carriers for the oral delivery of poorly available drugs and facilitate the use of this route This work summarises some experiments describing the bioadhesive potential of Gantrez nanoparticles fluorescently labeled with rhodamine B isothiocyanate The adhesive potential of Gantrez was found to be stronger when folded as nanoparticles than in the solubilised form Conventional nanoparticles displayed a tropism for the upper areas of the gastrointestinal tract, with a maximum of adhesion 30 min post-administration and a decrease in the adhered fraction along the time depending on the given dose The cross-linkage of nanoparticles with increasing amounts of 1,3-diaminopropane stabilised the resulting carriers and prolonged their half-life in an aqueous environment; although, the adhesive capacity of nanoparticles, the intensity and the relative duration of the adhesive interactions within the gut as a function of the cross-linking degree Finally, nanoparticles were coated with either gelatin or albumin In the first case, the presence of gelatin dramatically decreased the initial capacity of these carriers to interact with the gut mucosa and the intensity of these phenomenons In the latter, bovine serum albumin coated nanoparticles (BSA-NP) showed an important tropism for the stomach mucosa without further significant distribution to other parts of the gut mucosa
71 citations
TL;DR: 5,7-Di-tert-butylbenzoxazoles have shown activity against Mycobacterium tuberculosis and some nontuberculous strains where isoniazid has been inactive and antifungal activity was mediocre.
Abstract: A series of lipophilic 2-substituted 5,7-di-tert-butylbenzoxazoles was prepared in average yields by the reaction of 3,5-di-tert-butyl-1,2-benzoquinone with amino acids and dipeptides bearing N-terminal glycine. Dipeptides having other N-terminal amino acids undergo oxidative deamination. 5,7-Di-tert-butylbenzoxazoles have shown activity against Mycobacterium tuberculosis and some nontuberculous strains where isoniazid has been inactive. Antifungal activity was mediocre.
61 citations
TL;DR: Several compounds showed comparable activity to that of ampicillin against S. aureus and E. coli, and their Cu and Cd complexes were also tested for their antimicrobial activity.
Abstract: The coupling reaction of benzoic acid and nicotinic acid hydrazides with N- protected L-amino acids including valine, leucine, phenylalanine, glutamic acid and tyrosine is reported. The target compounds, N-Boc-amino acid-(N;-benzoyl)- and N- Boc-amino acid-(N;-nicotinoyl) hydrazides 5a-5e and 6a-6e were prepared in very high yields and purity using N-[(dimethylamino)-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl- methylene]-N-methyl-methanaminium hexafluorophosphate N-oxide (HATU) as coupling reagent. The antimicrobial activity of the Cu and Cd complexes of the designed compounds was tested. The products were deprotected affording the corresponding amino acid-(N;-benzoyl) hydrazide hydrochloride salts (7a-7e) and amino acid-(N;- nicotinoyl) hydrazide hydrochloride salts (8a-8e). These compounds and their Cu and Cd complexes were also tested for their antimicrobial activity. Several compounds showed comparable activity to that of ampicillin against S. aureus and E. coli.
TL;DR: A new diacetyl triterpene lactone, drosericarpone, was isolated from the hexane extract of the herb Cleome droserifolia, together with buchariol and stigmasterol glucoside.
Abstract: A new diacetyl triterpene lactone, drosericarpone (2), was isolated from the hexane extract of the herb Cleome droserifolia, together with buchariol (1, a sesquiterpene oxide, isolated for the first time from Cleome species) and stigmasterol glucoside (3). The structures of 1-3 were identified by spectroscopic means.
TL;DR: Treatment of 2-methylphenols with chloro(diphenyl)-λ3-iodane led to their regioselective dearomatizing 2-phenylation into cyclohexa-2,4-dienone derivatives via a proposed ligand coupling reaction.
Abstract: . Treatment of 2-methylphenols with chloro(diphenyl)-λ 3 -iodane led to their regioselective dearomatizing 2-phenylation into cyclohexa-2,4-dienone derivatives via a proposed ligand coupling reaction. In the same vein of investigation, treatment of 2-methylanilines with the λ 5 -iodane 2-iodoxybenzoic acid IBX reagent led to their regioselective dearomatization into previously undescribed ortho -quinol imines. Keywords: Iodanes, phenols, anilines, dearomatization, cyclohexadienones, orthoquinol imines. Introduction Arene dearomatization is a powerful tactic for the construction of complex organic molecules [1-3]. Our research efforts in this arena of synthetic organic chemistry rely in part on the use of λ 3 - and λ 5 -iodanes, i.e., hypervalent iodine(III) and iodine(V) compounds (Scheme 1) [4-10]. For example, the λ 3 -iodane of type ArIL 2 (L = heteroatomic ligand) (diacetoxy)iodobenzene (DIB) enables high-yielding conversion of 2-alkoxy and 2-alkylphenols into cyclohexa-2,4-dienone synthons that can then be utilized into various heterocyclization processes [7-9,11]. The [bis(trifluoroacetoxy)]iodobenzene (BTI) reagent can be used similarly to mediate regioselective carbon-carbon bond formation at substituted centers on naphthols [8,10]. The λ
TL;DR: Column chromatography of the alcoholic extract of Piper betle roots furnished aristololactam A-II and a new phenyl propene, characterized as 4-allyl resorcinol, while the petroleum-ether extract yielded a diketosteroid, viz. stigmast-4-en-3,6-dione.
Abstract: Column chromatography of the alcoholic extract of Piper betle roots furnished aristololactam A-II and a new phenyl propene, characterized as 4-allyl resorcinol, while the petroleum-ether extract yielded a diketosteroid, viz. stigmast-4-en-3,6-dione. All these compounds were characterized by spectroscopic means. Isolation of these compounds from this source is being reported here for the first time.
TL;DR: Peroxymaleic acid formed in situ from the reaction of UHP with maleic anhydride has a key role in this oxidation of thiols to the corresponding disulfides.
Abstract: Urea-hydrogen peroxide (UHP) was used in the presence of maleic anhydride as mediator in a simple and convenient method for the oxidation in high yield of some thiols to the corresponding disulfides. Peroxymaleic acid formed in situ from the reaction of UHP with maleic anhydride has a key role in this oxidation. Performance of the reaction in various solvents showed that methanol was the solvent of choice at 0 oC. The products were isolated by simple filtration on silica gel.
TL;DR: Bi(OTf)3 and SiO2-Bi3 are found to effectively catalyze the Ferrier rearrangement of tri-O-acetyl glycals with different alcohols providing an effective route to 2,3-unsaturated O-glycosides with good anomeric selectivity and good to excellent yields after short reaction times.
Abstract: Bi(OTf)3 and SiO2-Bi(OTf)3 are found to effectively catalyze the Ferrierrearrangement of tri-O-acetyl glycals with different alcohols providing an effective routeto 2,3-unsaturated O-glycosides with good anomeric selectivity and good to excellentyields after short reaction times.
TL;DR: A series of 22 novel 1,2-disubstituted-1H-benzimidazole-N-alkylated-5-carboxamidine derivatives were synthesized and evaluated for in vitro antibacterial activity against S. aureus and methicillin resistant S. faecalis and for antifungal activity against C. albicans.
Abstract: A series of 22 novel 1,2-disubstituted-1H-benzimidazole-N-alkylated-5- carboxamidine derivatives were synthesized and evaluated for in vitro antibacterial activity against S. aureus and methicillin resistant S. aureus (MRSA), E. coli, E. faecalis and for antifungal activity against C. albicans. Compound 59 [1-(2,4-dichlorobenzyl)-N- (2-diethylaminoethyl)-1H-benzimidazole-5-carboxamidine], with a 3,4-dichlorophenyl group at the C-2 position, displayed the greatest activity (MIC = 3.12 microg/mL against both some bacteria and the fungus C. albicans).
TL;DR: The Wittig-HTIB approach is a useful alternative to analogous sequences in which Tl(NO3)3·3H2O or the Prevost combination (AgNO3/I2) are employed in the oxidation step.
Abstract: The conversion of α-benzocycloalkenones to homologous β-benzocyclo-alkenones containing six, seven and eight-membered rings is reported. This wasaccomplished via a Wittig olefination-oxidative rearrangement sequence using[hydroxy(tosyloxy)iodo]-benzene (HTIB) is the oxidant, that enables the synthesis ofregioisomeric pairs of methyl-substituted β-benzocycloalkenones. The incorporation ofcarbon-13 at C-1 of the β-tetralone nucleus was also demonstrated. The Wittig-HTIBapproach is a useful alternative to analogous sequences in which Tl(NO3)3·3H2O or thePrevost combination (AgNO3/I2) are employed in the oxidation step.
TL;DR: A survey of the condensations of 3-formylchromone with various active methylene and methyl compounds, e.g. malonic or barbituric acid derivatives, five-membered heterocycles, etc.
Abstract: This review presents a survey of the condensations of 3-formylchromone with various active methylene and methyl compounds, e.g. malonic or barbituric acid derivatives, five-membered heterocycles, etc. The utilisation of the condensation products for the synthesis of different heterocyclic systems, which is based on the ability of the γ-pyrone ring to be opened by the nucleophilic attack is also reviewed. Finally, the applications of microwave irradiation as an unconventional method of reaction activation in the synthesis of condensation products is described and the biological activity of some chromone derivatives is noted.
TL;DR: A series of monosubstituted acetonitriles were treated with disulfur dichloride at room temperature in CH2Cl2 to afford 5-substituting-4-chloro-1,2,3-dithiazolium chlorides, which were sufficiently stable and soluble to provide both 1H- and 13C-NMR and cyclic voltammetry data.
Abstract: : A series of monosubstituted acetonitriles were treated with disulfur dichloride at room temperature in CH 2 Cl 2 to afford 5-substituted-4-chloro-1,2,3-dithiazolium chlorides 1 . Where the 5-substituent was not a good leaving group the chloride salts were converted into the corresponding perchlorate salts 2 which were sufficiently stable and soluble to provide both 1 H- and 13 C-NMR and cyclic voltammetry data. Several of the dithiazolium chlorides were converted into their corresponding 4-substituted-3-chloro-1,2,5-thiadiazoles 13 on treatment with aqueous ammonia. Mechanisms for all reactions are proposed. Keywords: 1,2,3-Dithiazole, 1,2,5-thiadiazole, heterocycle, heteroaromatic, electro-chemistry. Introduction The ready formation of 4,5-dichloro-1,2,3-dithiazolium chloride ( 1a ) from chloroacetonitrile and disulfur dichloride, S 2 Cl 2 , was described by Appel and coworkers, who also showed that the reactive 5-chlorine atom was smoothly displaced by a variety of nucleophiles [1]. This work has been widely applied to heterocyclic synthesis by Kim [2] and Rees [3]. Intramolecular reactions and nucleophilic opening of the dithiazole ring in derivatives of
TL;DR: Echinacea is an effective modulator of macrophage immune responses in vitro and the mixture of alkylamides in the Echinacea ethanolic liquid extract did not respond in the same manner in the assays as the individual alkyamides investigated.
Abstract: Echinacea preparations are widely used herbal medicines for the prevention and treatment of colds and minor infections. There is little evidence for the individual components in Echinacea that contribute to immune regulatory activity. Activity of an ethanolic Echinacea extract and several constituents, including cichoric acid, have been examined using three in vitro measures of macrophage immune function - NF-κB, TNF- α and nitric oxide (NO). In cultured macrophages, all components except the monoene alkylamide (AA1) decreased lipopolysaccharide (LPS) stimulated NF-κB levels. 0.2 µg/ml cichoric acid and 2.0µg/mL Echinacea Premium Liquid (EPL) and EPL alkylamide fraction (EPL AA) were found to significantly decrease TNF-α production under LPS stimulated conditions in macrophages. In macrophages, only the alkylamide mixture isolated from the ethanolic Echinacea extract decreased LPS stimulated NO production. In this study, the mixture of alkylamides in the Echinacea ethanolic liquid extract did not respond in the same manner in the assays as the individual alkylamides investigated. While cichoric acid has been shown to affect NF-κB, TNF-α and NO levels, it is unlikely to be relevant in the Echinacea alterations of the immune response in vivo due to its non- bioavailability - i.e. no demonstrated absorption across the intestinal barrier and no detectable levels in plasma. These results demonstrate that Echinacea is an effective modulator of macrophage immune responses in vitro.
TL;DR: The syntheses in good yields of some new difunctionalized 1,8-naphthyridines 4, 6, 8 and 9 and a novel triethylene glycol ether-linked dinaphthyrsidine, 10a, along with the mononaphTHyridine-linked ether alcohol 10b are described.
Abstract: The syntheses in good yields of some new difunctionalized 1,8-naphthyridines 4, 6, 8 and 9 and a novel triethylene glycol ether-linked dinaphthyridine, 10a, along with the mononaphthyridine-linked ether alcohol 10b are described. An improved and milder method for the synthesis of 2,7-diamino-1,8-naphthyridine (14) is also reported.
TL;DR: An efficient method of preparing biodegradable and biocompatible multiblock copolymers from lactic acid and polyethylene glycol is proposed.
Abstract: An efficient method of preparing biodegradable and biocompatible multiblock copolymers from lactic acid and polyethylene glycol is proposed.
TL;DR: Owing to this supramolecular complex formation, electrochemical DNA detection based on Ferrocenylnaphthalene diimide 1 was improved considerably and a 2:1 binding stoichiometry for β-CD to 1 threading-intercalated to the dsDNA-immobilized electrode was suggested.
Abstract: Ferrocenylnaphthalene diimide 1 can bind to double stranded DNA (dsDNA) by the threading intercalation mode and the resulting complex was stabilized further by β- cyclodextrin (CD) by forming a supramolecular complex. These complex formation processes were studied by spectroscopic, viscometric, and electrochemical means in the absence or presence of β-CD. Quantitative analysis by quartz crystal microbalance (QCM) and electrochemical experiments strongly suggested a 2:1 binding stoichiometry for β-CD to 1 threading-intercalated to the dsDNA-immobilized electrode. Owing to this supramolecular complex formation, electrochemical DNA detection based on 1 was improved considerably.
TL;DR: Two high-molecular water-soluble preparations with high anticomplementary, antioxidant, antilipoperoxidant and antiinflammatory activities were isolated from the roots of Symphytum asperum and S. caucasicum and can modulate in vitro B- chronic lymphocytic leukaemia cells apoptosis and cell cycle progression.
Abstract: Two high-molecular water-soluble preparations with high anticomplementary, antioxidant, antilipoperoxidant and antiinflammatory activities were isolated from the roots of Symphytum asperum and S. caucasicum. Their main chemical constituent was found to be poly[oxy-1-carboxy-2-(3,4-dihydroxyphenyl)ethylene], according to IR and NMR spectroscopy. The Symphytum high-molecular preparations can modulate in vitro B- chronic lymphocytic leukaemia (B-CLL) cells apoptosis and cell cycle progression.
TL;DR: Iminoester hydrochlorides 1 have been synthesized and a set of isatin imine derivatives 4 was obtained from the reaction of compounds 3 with isatin.
Abstract: : Iminoester hydrochlorides 1 have been synthesized. These compounds were then converted into ester ethoxycarbonyl hydrazones 2 , from which in turn a new series of substituted 4-amino-4,5-dihydro-1H-1,2,4-triazole-5-ones, 3 , was then prepared. Finally a set of isatin imine derivatives 4 was obtained from the reaction of compounds 3 with isatin. The structures of all the new synthesized compounds were confirmed by elemental analyses, IR, 1 H-NMR and 13 C-NMR spectra. Keywords: Iminoesters; ethoxycarbonyl hydrazones; 4-amino-1,2,4-triazole-5-ones; isatin Introduction The synthesis and antibacterial activity of some 4-amino-4,5-dihydro-1H-1,2,4-triazoles and their derivatives have been reported in the literature [1-5]. A number of studies involving the antibacterial and antitumor activity of some 4-amino-4,5-dihydro-1H-1,2,4-triazole-5-ones and their derivatives have also been published recently [6-14]. There are also many studies on isatin (1H-indole-2,3-dione) in the literature. The synthetic versatility of isatin has led to the extensive use of this compound in organic synthesis. This has stemmed in great part from the interest in the biological and pharmaceutical properties of its derivatives [15-24]. Although reactions of isatin with many amino compounds have been investigated, it appears that its reaction with the N-aminotriazole-5-ones have not been studied before. Consequently, some new 4-amino-4,5-dihydro-1H-1,2,4-triazole-5-ones have now been synthesized and their reactions with isatin investigated.
TL;DR: The Indigenous Bioresources Research Group (IBRG) aims to help Australian Aboriginal communities to preserve their customary medicinal knowledge, and to provide information that can be used for their cultural or educational purposes, as well as for scientific advancement.
Abstract: The Australian Aboriginal people have used plants as medicine and food for thousands of years, however, this traditional knowledge is documented only to a limited extent, and is in danger of being lost. The Indigenous Bioresources Research Group (IBRG) aims to help Australian Aboriginal communities to preserve their customary medicinal knowledge, and to provide information that can be used for their cultural or educational purposes, as well as for scientific advancement. This work is undertaken in close collaboration with Australian Aboriginal communities in New South Wales. The project is multidisciplinary, combining an ethnobotanical and an ethnopharmacological approach, which includes biological and chemical investigations, as well as developing best practices for protecting traditional knowledge. This paper describes the general strategy of the project as well as methods used in the ethnopharmacological study. Ethnobotanical databases are set up for each participating community. Plant material is collected, extracted, and active compounds are isolated using a bioassay-guided fractionation approach. All extracts and compounds are tested for biological activity in antimicrobial assays (disc diffusion, resazurin, fluorescein diacetate), neurological assays or anti-inflammatory assays, depending on their traditional use.
TL;DR: Cinnamic acids have been prepared in moderate to high yields by a new direct synthesis using aromatic aldehydes and aliphatic carboxylic acids, in the presence of boron tribromide as reagent.
Abstract: Cinnamic acids have been prepared in moderate to high yields by a new direct synthesis using aromatic aldehydes and aliphatic carboxylic acids, in the presence of boron tribromide as reagent, 4-dimethylaminopyridine (4-DMAP) and pyridine (Py) as bases and N-methyl-2-pyrolidinone (NMP) as solvent, at reflux (180-190°C) for 8-12 hours.
TL;DR: The synthesis of substituted 2-(6-nitrobenzo[1,3]dioxol-5-yl)-1-aryl ethanols and 2-chloromethyl-6-Nitrobenzaldehyde-3,3-dioxole with various aromatic carbonyl and α-carbonyl ester derivatives using the tetrakis(dimethylamino)ethylene (TDAE) methodology is reported.
Abstract: We report herein the synthesis of substituted 2-(6-nitrobenzo[1,3]dioxol-5-yl)-1- aryl ethanols and 2-(6-nitrobenzo[1,3]dioxol-5-yl)-propionic acid ethyl esters from the reaction of 5-chloromethyl-6-nitrobenzo[1,3]dioxole with various aromatic carbonyl and alpha- carbonyl ester derivatives using the tetrakis(dimethylamino)ethylene (TDAE) methodology.
TL;DR: The catalytic behavior of the studied complexes was shown to be dependent on the conditions applied and acetophenone and 1- phenylethanol were the only observed products in all reactions.
Abstract: Schiff-Base complexes of bis-5-phenylazosalicylaldehyde ethylenediimine and bis-5-phenylazosalicylaldehyde-O-phenylenediimine ligands with Co(II) (I and II) have been synthesized and characterized by their IR spectra and elemental analyses. These complexes catalyze the oxidation of styrene in the presence of dioxygen and excess pyridine. The effect of the reaction conditions on the oxidation of styrene was studied by varying solvent, nature and amount of the catalyst and substrate. The catalytic behavior of the studied complexes was shown to be dependent on the conditions applied. In all reactions, acetophenone and 1- phenylethanol were the only observed products.