Glicerol: um breve histórico e aplicação em sínteses estereosseletivas

Presently glycerol is considered a co-product of biodiesel industry. As the biodiesel production is exponentially increasing, glycerol generated from the transesterification of vegetable oils and fats is also being produced on a large scale, and turned out to be essential seeking for novel alternatives to the consumption of the extra volume, in crude and/or as derivatives high added value. This review mainly deals with chemical and enzymatic transformations of glycerol to obtain chiral building blocks for synthesis of pharmaceuticals and natural products

Design, Synthesis and in vitro Antimicrobial Activity Evaluation of Novel Hybrids of Lichexantone-THC Derivatives

Two novel hybrid lichexantone-THC (benzopirane group) derivatives as potential antimicrobial agents were designed and prepared from norlichexanthone and (S)-cis-verbenol in two steps. The newly synthesized compounds were characterized by 1H-NMR, 13C-NMR and MS. In addition, we evaluated the in vitro antimicrobial activity against Gram-positive (Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium) and Gram- negative (Escherichia coli, Enterobacter cloacea, Klebisiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa) bacterial strains. The bioassay results indicate that the compounds namely 5 and 6 proved active against Gram-positive strains (standard and clinical) in comparison with reference drugs. DOI: http://dx.doi.org/10.17807/orbital.v7i4.78

A Straightforward Method for Synthesizing Bioactive Resorcinolic Lipid Analogues

Resorcinolic lipids, a class of bioactive amphiphilic molecules found widely in nature, hold potential for a variety of biological and industrial applications. This report describes the synthesis of three bioactive structural analogues of resorcinolic lipids, obtained by subjecting ethyl (E)-2-undecenoate and ethyl acetoacetate to a Michael reaction in the presence of sodium ethoxide to generate a Michael adduct, followed by cyclization in the reaction medium. Ethyl 2-octyl-4,6-dioxocyclohexanecarboxylate (7) was thus produced with a 60% yield. To perform an aromatization step, 7 was subsequently treated with I2 in methanol under reflux, producing a combined 80% yield of 2,4-dimethoxy-6-octyl-ethyl benzoate (1) and 2-hydroxy-4-methoxy-6-octyl-ethyl benzoate (2) at a 7:3 ratio, respectively. 2-Hydroxy-4-methoxy-6-octyl-benzoic acid was obtained with a 60% yield by treating 1 with BBr3/CHCl3. The structures of the synthesized compounds and intermediates were elucidated by 1H and 13C NMR spectroscopy, employing two-dimensional techniques (HSQC and HMBC). DOI: http://dx.doi.org/10.17807/orbital.v12i2.23

A Straightforward Method for Synthesizing Bioactive Resorcinolic Lipid Analogues

Resorcinolic lipids, a class of bioactive amphiphilic molecules found widely in nature, hold potential for a variety of biological and industrial applications. This report describes the synthesis of three bioactive structural analogues of resorcinolic lipids, obtained by subjecting ethyl (E)-2-undecenoate and ethyl acetoacetate to a Michael reaction in the presence of sodium ethoxide to generate a Michael adduct, followed by cyclization in the reaction medium. Ethyl 2-octyl-4,6-dioxocyclohexanecarboxylate (7) was thus produced with a 60% yield. To perform an aromatization step, 7 was subsequently treated with I2 in methanol under reflux, producing a combined 80% yield of 2,4-dimethoxy-6-octyl-ethyl benzoate (1) and 2-hydroxy-4-methoxy-6-octyl-ethyl benzoate (2) at a 7:3 ratio, respectively. 2-Hydroxy-4-methoxy-6-octyl-benzoic acid was obtained with a 60% yield by treating 1 with BBr3/CHCl3. The structures of the synthesized compounds and intermediates were elucidated by 1H and 13C NMR spectroscopy, employing two-dimensional techniques (HSQC and HMBC). DOI: http://dx.doi.org/10.17807/orbital.v12i2.23

Seasonal and spatial variation of the iridoid specioside in monodominant formation of Tabebuia aurea in the Brazilian Pantanal wetland/ Variação sazonal e espacial do especiosídeo iridóide em formação monodominante de Tabebuia aurea na zona húmida do Pantanal brasileiro

It is common in the Pantanal the occurrence of monodominant formations, such as “paratudal” dominated by Tabebuia aurea. Although it is of high importance, little is known about how it is maintained and what factors limit its progress. We investigated the variation of secondary metabolism between individuals located on the edge and center of the formation as well as the effect of flood pulse and what part of the plant (stem bark or leaves) is there greater accumulation of iridoids glycosides, and if is there a translocation of specioside between them. We collected stem bark and leaves samples from individuals of T. aurea located in the center and edge of paratudal in drought and flooded season, sampled individuals were the same in both seasons. We also analyzed the topographic profile of paratudal. Ours results showed that the specioside concentration in stem bark decreased during flood season only on the edge of paratudal and this region was lower than the center. Individuals located on the edge stay more time exposed to the flooding effect. These results suggest that the flooding is the main cause of the change in the specioside concentration on monodominant formation and the topography should delimitate the monoformation

Insights of Cannabinoid CBD: The Pharmacological Potential and Heterologous Expression

In this review, a thorough approach was taken to the therapeutic potential of CBD and the possibilities of heterologous expression for its synthesis. Synthesizes the most recent discoveries on the medicinal benefits of CBD, its mode of action, and different methodologies that aim to maximize CBD production using heterologous expression systems. This review contributes to increasing knowledge about the wide range of uses of CBD and its potential in industries, including biotechnology and medicine

Synthesis of angiotensin-converting enzyme (ACE) inhibitors: an important class of antihypertensive drugs

This report outlines the discovery, the design and development of new compounds, and, structure-activity relationships for this drug category. Updated approaches to planned syntheses of new worthy ACE-inhibitors are also exploited

Editorial: Chemistry: A key science to fight neglected diseases/Química: Ciência central para combater doenças negligenciadas

Over the past century, chemical and pharmaceutical industries have made substantial strides in the development of new pharmaceuticals for a range of human diseases. Discovering and developing new drugs are part of a costly process that involves not only the search for new drug candidates, but also the performance of clinical trials. It is not uncommon to find reports of costs reaching US$500 million—and even US$ 1 billion—engaging multidisciplinary teams for periods of 10 or 15 years. To a large extent, these costs are borne by consumers in richer countries. In contrast, diseases that predominantly affect residents of poorer nations tend to be left out of the modern process of drug discovery. Moreover, most of the world population stricken by these illnesses is incapable of supporting the costs involved in developing the drugs they need. Because these infirmities, with few exceptions, have been ignored by those in charge of research programs, both in the public and private sectors, they have been referred to as neglected diseases. On its website, the World Health Organization categorizes 14 health conditions as “tropical diseases,”......................

Four years of crusade!

<p>Orbital - The Electronic Journal of Chemistry is entering its 4th year of existence which is a reason to celebrate. A great work has been devoted to preserve a scientific journal of international reputation. This work was not always without mistakes or any trouble. However, these very adversities stimulate additional efforts in order to overcome our errors and, continuing with our serious proposal of editing a journal which scientists from all over the world can submit online their original works manuscripts to be published in peer review and open-access style.</p> <p>Beginning this year, Orbital was classified by the Chemistry Coordination Area on the B5 rank of CAPES Qualis (Brazil) and, leveled as B4 by Coordination Areas of Materials and Engineering II. These important details demonstrate that Orbital is progressively attaining the acknowledgment of the Brazilian scientific community. The recognition by CAPES Qualis is crucial as the system evaluates the generation of knowledge in the Brazilian universities and the method by which this same knowledge disseminated to society. Not all these were possible without endeavoring of editors and volunteer assistance of advisors from several national and international institutions.</p> <p>Recently, the young Professors Kleber Thiago de Oliveira (UFSCAR), Grégoire Demetz (USP-RP) and Amilcar Machulek Júnior (UFMS) have joined us to share the idea and philosophy of Orbital by accepting our invitation to be associated editors. The tasks and challenges are enormous and, we are sure that new participants will support us on the way to achieve indexation in new Databases systems as SCOPUS, ISI and Scielo. Consequently, the international success of this electronic journal will be assured.</p> We sincerely hope that in the academic Brazilian scenario, Orbital can figure as a solid bridge to interchange real creative science that is happening in various locations around the world