Cancer is a complex disease which involves abnormalities of multiple cellular pathways. Current chemotherapeutic drugs are mainly designed to target the DNA and cell division. Therefore, in the present study, we have synthesized a new series of 1,2,3-triazolo-naphthalimide/phthalimide conjugates and evaluated their in vitro cytotoxicity against selected human cancer cells. Among the tested compounds, one of them displayed notable cytotoxic activity against A549 lung cancer cells with an IC50 (half maximal inhibitory concentration) value of 7.6 ± 0.78 µM. To determine the effect of this compound on cell viability, acridine orange/ethidium bromide (AO/EB) and 4',6-diamidino-2-phenylindole (DAPI) staining studies were performed. These apoptotic features were clearly indicating that the compound inhibited cell proliferation by apoptosis. Further, relative viscosity measurements and molecular docking studies with the most three active compounds indicated that these new compounds bind to DNA by intercalation.

A facile and new metal-free 1,3-dipolar cycloaddition reaction for the synthesis of 4-aryl-NH-1,2,3-triazoles from nitroolefins and NaN3 employing NH2SO3H has been developed. Sulfamic acid proved to be an efficient additive in this transformation by inhibiting the formation of triaryl benzene. Mechanistic aspects and key intermediates associated with this transformation have also been characterized by online monitoring of the reaction using electrospray ionization tandem mass spectrometry method (ESI-MS/MS). The protocol emphasizes broad substrate scope for many functionalities, simple reaction conditions such as stability to open air, less reaction time, easy work-up, eco-friendly and with good to excellent yields.

A new approach based on multicomponent/domino combined reactions for the synthesis of γ-nitroesters promoted by a mixed aluminium-magnesium oxides derived from hydrotalcite-like material was developed. Different γ-nitroesters were synthesized in 15-95% yield using Meldrum's acid, aromatic aldehydes, nitromethane and different alcohols as reagents and solvents. The γ-aminobutyric acid derivatives, Phenibut and Baclofen, were prepared in 63 and 61% overall yield, respectively, through a two steps synthetic strategy. A mechanistic pathway was proposed based on the gas chromatography mass spectrometry (GC-MS) and electrospray ionization mass spectrometry (ESI-MS) experiments.

For the first time, the adsorption of pesticides such as azinphos-methyl and methamidophos by polyamidoamine (PAMAM) derivatives was studied. Amine groups of PAMAM (G4 and G5) were functionalized with different biomolecules such as folic acid, coumarine, arginine, lysine, and asparagine. Subsequently, the synthesized compounds were used to trap organophosphates (OP), and its affinity to do so was measured by high-performance liquid chromatography (HPLC). The obtained experimental data was compared with the interaction energy values obtained through a nanoinformatic methodology, by using conformational sampling through Euler angles and semi‑empirical quantum mechanical calculations. Both, the experimental and the in silico methodology can be employed to screen with high accuracy the molecular interactions between OP agents and the functionalized PAMAM. Furthermore, affinity results by HPLC and molecular dynamics were supported by in vitro enzyme acetylcholinesterase activity assays.

O fascínio do homem por reações químicas remonta aos tempos antigos. Com a introdução de técnicas espectroscópicas, a arte de explorar as reações se tornou uma ciência intrigante. Portanto, não é surpreendente que uma das fronteiras mais prósperas e gratificantes na Química moderna é o estudo de mecanismo de reações em processos químicos e biológicos. Como a imaginação do homem não termina nas fronteiras definidas pela natureza, e com o poder crescente da catálise, o químico orgânico sintético está pronto para contribuir de uma maneira importante no invento e desenvolvimento de novas tecnologias que permitam a geração de novos catalisadores e metodologias. Neste account uma nova ferramenta para acelerar o desenvolvimento na descoberta de novas reações é revisada através do monitoramento por espectrometria de massa com ionização eletrospray (ESI-MS).

Man's fascination with chemical reactions goes back to ancient times. With the introduction of spectroscopic techniques, the art of exploiting reactions became an intriguing science. It is, therefore, not surprising that one of the most flourishing and rewarding frontiers in modern Chemistry is the study of reaction mechanisms in chemical and biological processes. As man's imagination does not stop at the frontiers defined by nature, and with the ever increasing power of catalysis, the synthetic organic chemist is poised to make important contributions by inventing and developing new enabling technologies for the generation of new catalysts and methodologies. In this account is offered a new tool for accelerating the development through electrospray ionization-mass spectrometric (ESI-MS) monitoring in new reaction discovering.

As estruturas dos produtos de degradação mediada por ozônio de diferentes compostos farmacêuticos foram estudadas. Uma completa degradação do nadolol foi observada nas condições empregadas após 100 min. Os produtos de degradação obtidos nas soluções aquosas foram caracterizados por espectrometria de massas com ionização por electrospray (ESI-MS e ESI-MS/MS). O mecanismo proposto para a degradação consiste inicialmente do ataque de ozônio ao grupo amino da anilina formando nitro compostos, seguida de uma série de processos oxidativos. Monitoramento por ESI-MS(/MS) mostrou que a degradação de atenolol (ATE) e acebutolol (ACE) por ozônio ocorrem via um mecanismo similar ao do nadolol

The structures of intermediate products of ozone degradation of different pharmaceutical compounds have been studied. Under the conditions employed, complete ozone degradation of nadolol was achieved after 100 min. The degradation products obtained in aqueous solution were characterized by electrospray ionization mass (and tandem mass) spectrometry (ESI-MS and ESI-MS/MS). The proposed mechanism for degradation, ozone attacks at the aniline amino group giving rise to nitro compounds and further degradation occurs via a series of oxidative processes. Continuous online monitoring by ESI-MS(/MS) with high accuracy mass measurements showed that ozone degradation of atenolol (ATE) and acebutolol (ACE) occurs via mechanisms similar to that of nadolol

After the progress made during the genomics era, bioinformatics was tasked with supporting the flow of information generated by nanobiotechnology efforts. This challenge requires adapting classical bioinformatic and computational chemistry tools to store, standardize, analyze, and visualize nanobiotechnological information. Thus, old and new bioinformatic and computational chemistry tools have been merged into a new sub-discipline: nanoinformatics. This review takes a second look at the development of this new and exciting area as seen from the perspective of the evolution of nanobiotechnology applied to the life sciences. The knowledge obtained at the nano-scale level implies answers to new questions and the development of new concepts in different fields. The rapid convergence of technologies around nanobiotechnologies has spun off collaborative networks and web platforms created for sharing and discussing the knowledge generated in nanobiotechnology. The implementation of new database schemes suitable for storage, processing and integrating physical, chemical, and biological properties of nanoparticles will be a key element in achieving the promises in this convergent field. In this work, we will review some applications of nanobiotechnology to life sciences in generating new requirements for diverse scientific fields, such as bioinformatics and computational chemistry.

Espectrometria de massas sequencial usando infusão direta de amostra e ionização por electrospray no modo de ions negativos foi utilizada para quantificar taurina em bebidas energéticas com alta seletividade e sensibilidade, O metodo é simples e rápido (menos de 2 min de corrida) e apresenta alta repetitividade e recuperação. Bebidas energéticas comerciais apresentaram quantidades de taurina em concentrações muito diferentes (menor ou maior) das quantidades declaradas.

Direct infusion electrospray ionization tandem mass spectrometry in the negative ion mode with single reaction monitoring is show to allow high selectivity and sensitivity in the quantification of taurine in energetic drinks. The method is also simple and rapid (less than 2 min run time), with high recovery and repeatability. Commercially available energetic drinks were found to contain taurine in concentrations quite different (lower or higher) from the declared amounts.

Uma abordagem enantiosseletiva eficiente para a preparação de centros quaternários a partir da prolina 5 foi desenvolvida através do rearranjo [2,3]-sigmatrópico de Stevens, co-catalisado por líquido iônico. O rearranjo sigmatrópico foi estereoespecífico porque as migrações-[2,3] foram restritas à mesma face e a estereosseletividade surgiu na etapa preliminar da N-alquilação em 8. O método mostrou melhores rendimentos do que os descritos na literatura. O uso de hexafluorofostato de 1-butil-3-metilimidazólio mostrou uma melhora nos rendimentos do rearranjo de Stevens devido a possível estabilização e/ou ativação das espécies zuiteriônicas em solução, pelo líquido iônico. Diversas indolizidinas foram sintetizadas a partir do derivado (S)-5 da prolina quaternária.

An efficient enantioselective approach for preparation of quaternary centers from proline 5 building block has been developed through [2,3]-sigmatropic Stevens rearrangement co-catalyzed by ionic liquid. The sigmatropic rearrangement was stereospecific because the [2,3]-migrations were restricted to the same face, and the stereoselectivity arose from the previous N-alkylation step in 8. The approach showed better yields than described in literature. The use of 1-butyl-3-methylimidazolium hexafluorophosphate showed an improvement in the yields of the Stevens rearrangement due to a possible stabilization and/or activatation of zwiterionicspecies in solution by the ionic liquid. Several indolizidine moieties were synthesized from quaternary proline derivative (S)-5.

A reação radicalar mediada por hidreto de tri-n-butilestanho de 2,3-di-O-benzil-4-O-trans-cinamil-6-desoxi-6-(2-iodobenzoilamino)- alfa-D-galactopyranosídeo de metila levou à formação de um produto inesperado, o 2,3-di-O-benzil-4-O-trans-cinamil-6-desoxi-6-(2-tri- n-butilestanhobenzoilamino)-alfa-D-galactopyranosídeo de metila. A estrutura do produto foi elucidada por meio das espectrometrias de RMN unidimensionais (¹H, 13C e DEPT) e bidimensionais (COSY e HMQC) e confirmada por espectrometria de massas. Foram apresentadas propostas de mecanismos para explicar a formação do derivado organoestanho.

The tri-n-butyltin hydride-mediated reaction of methyl 2,3-di-O-benzyl-4-O-trans-cinnamyl -6-deoxy-6-(2-iodobenzoylamino)-alpha-D-galactopyranoside afforded an unexpected aryltributyltin compound. The structure of this new tetraorganotin(IV) product has been elucidated by ¹H, 13C NMR spectroscopy, COSY and HMQC experiments and electrospray ionization mass spectrometry (ESI-MS). The formation of this new compound via a radical coupling reaction and a radical addition-elimination process is discussed.

A oxidação de álcoois homoalílicos terciários com trinitrato de tálio (TTN) foi investigada. Os álcoois que possuem uma metila na posição alílica perdem uma molécula de acetona via uma reação de fragmentação, levando a uma mistura de álcoois alílicos isoméricos como principais produtos, juntamente com os correspondentes derivados acetilados. Por outro lado, o tratamento com TTN de álcoois terciários análogos, sem a metila na posição alílica, fornece indanos, através de uma reação de contração de anel.

The oxidation of tertiary homoallylic alcohols with thallium trinitrate (TTN) was investigated. The alcohols bearing an allylic methyl group lose a molecule of acetone via a fragmentation reaction that leads to isomeric secondary allylic alcohols as major products, together with their corresponding acetylated derivatives. On the other hand, treating analogous tertiary alcohols without the allylic methyl group with TTN gives indans, through a ring contraction reaction.

O extrato etanólico das folhas de Nectandra grandiflora coletadas na Mata Atlântica, Brasil, mostrou atividade antioxidante frente ao b-caroteno em teste usando cromatografia em camada delgada. O fracionamento biomonitorado levou ao isolamento do ácido protocatecuico e de dois flavonóides glicosilados: afzelina e quercetrina, os quais exibiram atividade sequestradora de radicais livres frente ao DPPH (DA 32, 16 e 73% a 50 µmol L-1) e foram comparados aos antioxidantes comerciais rutina (81% a 50 µmol L-1) e BHT (9% a 50 µmol L-1), usados como substâncias de referência. Além disso, três neolignanas inativas, incluindo a nova neolignana biciclo[3.2.1]octânica 2'-oxo-piperol B, foram obtidas e caracterizadas por métodos espectrométricos.

The EtOH crude extract from the leaves of Nectandra grandiflora collected in the Atlantic Forest, Brazil, showed antioxidant activity towards b-carotene in a TLC assay. The bioassay-guided fractionation led to the isolation of protocatechuic acid and two flavonol glycosides: afzelin and quercetrin, which showed free radical scavenging activity towards DPPH (DA 32, 16 and 73% at 50 µmol L-1) and were compared to commercial antioxidants rutin (81% at 50 µmol L-1) and BHT (9% at 50 µmol L-1), used as standard compounds. Additionally, three inactive neolignans, including the new bicycle[3.2.1]octane neolignan 2'-oxo-piperol B were obtained and characterized by spectrometric methods.

A adição de 5-metil-2-tri-isopropilsililoxifurano (5) a N-carbobenziloxi-2-metoxipiperidina (6a) forneceu uma mixtura dos isômeros eritro e treo 7a and 8a, respectivamente, em rendimentos de moderado a bom (42-85%) e razão diastereoisomérica (7a : 8a) variando entre 1,1:1 _ 6:1, dependendo do sistema de solvente e do ácido de Lewis empregados. O isômero treo 8a foi transformado na (+/-)-homopumiliotoxina 223G (1) que foi obtida a partir de 6a em 5 etapas e 13% de rendimento total.

The addition of 5-methyl-2-triisopropylsilyloxyfuran (5) to N-carbobenzyloxy-2-methoxypiperidine (6a) afforded a mixture of the corresponding erythro and threo isomers 7a and 8a, respectively, in moderate to good yields (42-85%) and diastereoisomeric ratio (7a : 8a) ranging from 1.1:1 _ 6:1 depending on the solvent system and the Lewis acid employed. The threo isomer 8a was eventually converted to (+/-)-homopumiliotoxin 223G (1) which was prepared in 5 steps and 13% overall yield from 6a.