Erick Leite Bastos

Erick Leite Bastos
University of São Paulo | USP · Departamento de Química Fundamental (IQ) (São Paulo)

PhD

About

127
Publications
27,588
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Introduction
Our research group investigates natural fluorescent pigments in order to establish structure-property relationships and to create new functional chemicals. This includes the development of fluorescent probes and markers for cell biology, antioxidants for use in food and cosmetics, biodegradable surfactants and fluorescent hybrid nanoparticles.
Education
July 2000 - October 2004
University of São Paulo
Field of study
  • Organic Chemistry
July 1994 - June 1998
Mackenzie Presbyterian University
Field of study
  • Chemistry
July 1988 - June 2000
University of São Paulo
Field of study
  • Organic Chemistry

Publications

Publications (127)
Article
Metal nanoparticles have been widely exploited in catalysis, but their full impact on the environment and human health is still under debate. Here we describe the one-step fabrication of recoverable and reusable polymer microbead-supported metal and metal oxide nanocatalysts for application in batch reactions and flow systems. Au, Ag and Fe3O4 nano...
Article
Full-text available
Blue natural pigments are rare, especially among plants. However, flowering species that evolved to attract Hymenoptera pollinators are colored by blue anthocyanin-metal complexes. Plants lacking anthocyanins are pigmented by betalains but are unable to produce blue hues. By extending the π-system of betalains, we designed a photostable and metal-f...
Article
Full-text available
Betaxanthins are natural products with high antioxidant and anti-inflammatory properties. Here, we describe the semisynthesis of twenty-one betaxanthins derived from proteinogenic amino acids, including the elusive betaxanthin of l-cysteine and two betaxanthins derived from l-lysine, and rationalize their antioxidant properties in mechanistic terms...
Article
Nitrones derived from natural antioxidants are emerging as highly specific therapeutics against various human diseases, including stroke, neurodegenerative pathologies, and cancer. However, the development of useful pseudo-natural nitrones requires the judicious choice of a secondary metabolite as the precursor. Betalains are nitrogen-containing na...
Article
Water decreases the brightness of the peroxyoxalate chemiluminescence partially due to the hydrolysis of the oxalate reagent. Here, we show that encapsulation of an oxalate ester and the fluorescent activator in microspheres of cellulose esters increases the emission intensity 30 times compared to the same reaction in water without encapsulation, w...
Article
More than 125 known species of fungi, all part of the Agaricales order, can spontaneously emit light. This bioluminescence results from the oxidation of a luciferin derived from caffeic acid by oxygen under the action of the enzyme luciferase. The production and regeneration of caffeic acid tie together the Krebs cycle and the Shikimic Acid pathway...
Article
Full-text available
Bioluminescence (BL) and chemiluminescence (CL) are interesting and intriguing phenomena that involve the emission of visible light as a consequence of chemical reactions. The mechanistic basis of BL and CL has been investigated in detail since the 1960s, when the synthesis of several models of cyclic peroxides enabled mechanistic studies on the CL...
Article
In DNA, electron excitation allows adjacent pyrimidine bases to dimerize by [2 + 2] cycloaddition, creating chemically stable but lethal and mutagenic cyclobutane pyrimidine dimers (CPDs). The usual cause is ultraviolet radiation. Alternatively, CPDs can be made in the dark (dCPDs) via chemically mediated electron excitation of the skin pigment mel...
Article
The parameters which determine the efficiency of chemiluminescence, and bioluminescence transformations are a continuous matter of experimental and theoretical studies. In this sense, we report here a study of the solvent polarity influence on four Chemically Initiated Electron Exchange Luminescence (CIEEL) systems. Two of them comprise intermolecu...
Article
Full-text available
The l-DOPA dioxygenase of Amanita muscaria (AmDODA) participates in the biosynthesis of betalain- and hygroaurin-type natural pigments. AmDODA is encoded by the dodA gene, whose DNA sequence was inferred from cDNA and gDNA libraries almost 30 years ago. However, reports on its heterologous expression rely on either the original 5'-truncated cDNA pl...
Chapter
This chapter revises the application of UV-Vis spectrophotometry and spectrofluorimetry in bioanalysis. It focuses on techniques that rely on the absorption and emission of light for the detection and/or quantification of species in biological matrices. Key concepts in photochemistry and photophysics are briefly revisited to provide the theoretical...
Article
Peroxyoxalate chemiluminescence is used in self-contained light sources, such as glow sticks, where oxidation of aromatic oxalate esters produces a high-energy intermediate (HEI) that excites fluorescence dyes via electron transfer chemistry, mimicking bioluminescence for efficient chemical energy-to-light conversion. The identity of the HEI and re...
Article
Full-text available
Esse artigo traz algumas reflexões sobre o uso de ferramentas de ensino on-line no ensino presencial. O autor compartilha suas as dúvidas sobre a melhor forma de conciliar as lições aprendidas com o ensino on-line durante o distanciamento social imposto pela pandemia de COVID-19 e o retorno das aulas presenciais. Além disso, são abordados aspectos...
Chapter
Full-text available
An overview is provided of the status of research on the antioxidant and radical- scavenging properties of betalains, water-soluble pigments found in plants, fungi, and bacteria. Together with anthocyanins, betalains are responsible for most of the red, purple, and blue colors of fruits and fl owers, although both classes of secondary metabolites ar...
Preprint
div> Nitrones derived from natural antioxidants are emerging as highly specific therapeutics against various human diseases, including stroke, neurodegenerative pathologies, and cancer. However, the development of useful pseudo-natural nitrones requires the judicious choice of a secondary metabolite as the precursor. Betalains are nitrogen-contai...
Chapter
Full-text available
An overview is provided of the status of research on the antioxidant and radical-scavenging properties of betalains, water-soluble alkaloids found in plants, fungi and bacteria. Together with anthocyanins, betalains are responsible for most of the red, purple and blue colors of fruits and flowers, although both classes of secondary metabolites are...
Article
Betalains are antioxidant secondary metabolites that emerged as safe color additives for food and cosmetics, fluorescent dyes, and redox mediators. Herein, we describe the semisynthesis of N-methyl phenylbetalain (mepBeets) and N-aryl phenylbetalain (dipBeets) dyes and compare the effect of the structure on their hydrolytic stability and electronic...
Article
Full-text available
Dendrimeric copper nanoparticles (CuNPs) were prepared by the reduction of [Cu2(CH3CO2)4] with ascorbic acid at 75 °C in the presence of ranelate ions. The metallic nanoparticles exhibited a strong plasmonic band centered at 581 nm, and their average size distribution was typically in the range of 20–30 nm. By adding polyvinylpyrrolidone to the rea...
Preprint
L-DOPA extradiol dioxygenases (DODAs) catalyze the production of betalains and hygroaurins pigments. The sequence of the DODAs found in Caryophyllales and Basidiomycetes are not conserved, although betalains are produced both by plants and fungi. Here we revise the coding region of the dodA gene of fly agaric [Amanita muscaria (L.) Lam.] and descri...
Article
While thermal treatment of paper can lead to the formation of aromatic structures via hydrothermal treatment (low temperature) or pyrolysis (high temperature), neither of these approaches allow patterning the substrates. Somewhere in between these two extremes, a handful of research groups have used CO2 lasers to pattern paper and induce carbonizat...
Article
Rationale: Methods for isomer discrimination by mass spectroscopy are of increasing interest. Here we describe the development of a 3D ion trap for Infrared Multiple Photon Dissociation (IRMPD) spectroscopy that enables the acquisition of the infrared spectrum of selected ions in the gas phase. This system is suitable for the study of myriad chemi...
Article
Full-text available
Betalains are water-soluble natural pigments of increasing importance as antioxidants for pharmaceutical use. Although non-phenolic betalains have lower capacity to scavenge radicals compared to their phenolic analogues, both classes perform well as antioxidants and anti-inflammatory agents in vivo. Here we show that meta-hydroxyphenyl betalain (m-...
Article
Full-text available
Light-driven reduction of flavins, e.g. FAD or FMN, by sacrificial electron donors emerged as a convenient method to promote biocatalytical transformations. However, flavin activation has been restricted to oxygen-free conditions to prevent enzyme deactivation caused by reactive oxygen species (ROS). Herein, we show that the photoreduction of FMN b...
Article
Full-text available
Betalains are phytochemicals of nutraceutical importance that emerged as potent antioxidants, preventing radical chain propagation and the deleterious health effects of oxidative stress. However, despite the wide application of betalains as color additives in products for human consumption, little is known about the relationship between their struc...
Article
Full-text available
The use of enzymes for synthetic applications is a powerful and environmentally-benign approach to increase molecular complexity. Oxidoreductases selectively introduce oxygen and hydrogen atoms in myriad substrates, catalyzing the synthesis of chemical and pharmaceutical building blocks for chemical production. However, broader application of this...
Chapter
Fluorescence is a visually appealing phenomenon that revolutionized many fields of science and technology. The abilities to see biological processes as they occur, monitor drug delivery and action, stain specific cells, and highlight microscopic structures are some of the applications of fluorescence that are changing our daily lives. This chapter...
Article
Full-text available
We developed a project during an undergraduate course (advanced experimental chemistry) on the microwave-assisted synthesis of biodiesel (BD), via base-catalyzed transesterification of coconut fat (CF) and soybean oil (SO) by ethanol, followed by product analysis by gas chromatography/mass spectrometry. Our goals were to introduce a problem with re...
Article
Excited state intramolecular proton transfer (ESIPT) is a widespread phenomenon that has been exploited in several analytical and technological applications. Here we describe the synthesis of two ESIPT-active halogen-substituted naphthol-oxazolines that can be conveniently functionalized to develop tailored sensors, and a bis-oxazoline that showcas...
Article
Betanin is the main pigment of the food color beetroot red (E162). Due to the fair heat and light stability of E162, this pigment is mainly used in minimally processed packaged food products. Encapsulation increases the stability of betanin, but detailing on the effect of different sources of betanin on the properties and stability of multiple emul...
Article
Full-text available
ABSTRACT An overview is provided of the status of research at the frontiers of investigation of the chemistry and photochemistry of two classes of natural plant pigments, the anthocyanins and the betalains, as well as of the pyranoanthocyanin pigments formed from anthocyanins during the maturation of red wine. Together, anthocyanins and betalains a...
Article
Full-text available
The efficient conversion of light energy into chemical energy is key for sustainable human development. Several photocatalytic systems based on photovoltaic electrolysis have been used to produce hydrogen via water reduction. However, in such devices, light harvesting and proton reduction are carried separately, showing quantum efficiency of about...
Article
The structural modification of plant pigments allows the development of new functional dyes with tailored photophysical properties. Two-photon excitation fluorescence microscopy has emerged as an important technique, but requires the use of fluorophores having large two-photon absorption cross-sections in water. This feature is rarely found in natu...
Chapter
Betalains are chiral water-soluble alkaloids that have been used as safe food colorants, nutraceuticals, and as starting materials for advanced materials. The increasing interest in this class of secondary metabolites of plants promoted the optimization and scale-up of methods for obtaining them. This chapter reviews the physicochemical properties...
Chapter
This chapter presents the main aspects of acid–base reactions of transition-metal enolates and an overview of solvent effects on the chemical reactivity of metal enolates.
Chapter
This chapter is an update of a recent review on the acid–base chemistry and solvation properties of metal phenolates. After a brief introduction on the physicochemical properties of metal phenolates, the interaction between phenolate ligands and metal Lewis acids is discussed. Examples of solvent effects on the acid–base properties, structure, and...
Article
Four-membered cyclic peroxides are high-energy compounds often associated to cold light emission, but whose chemical and biological roles are still matters of debate. The often-dangerous synthesis of 1,2-dioxetanes, achieved around 50 years ago, has been mastered over the years to a point where some derivatives are commercially available. This fact...
Article
Full-text available
Bioluminescent fungi are spread throughout the globe, but details on their mechanism of light emission are still scarce. Usually, the process involves three key components: an oxidizable luciferin substrate, a luciferase enzyme, and a light emitter, typically oxidized luciferin, and called oxyluciferin. We report the structure of fungal oxyluciferi...
Chapter
This chapter presents an overview of the fundamental aspects of the formation and structure of metal enolates, focusing on the consequences of acid–base and solvation properties of main-group metal enolates on their chemical reactivity. Reference data such as equilibrium and acid dissociation constants are compiled.
Article
Almost all chemiluminescent and bioluminescent reactions involve cyclic peroxides. The structure of the peroxide and reaction conditions determine the quantum efficiency of light emission. Oxidizable fluorophores, the so-called activators, react with 1,2-dioxetanones promoting the former to their first singlet excited state. This transformation is...
Article
Herein, we report a nano-hybrid photo-system based on abundant elements for H2 production with visible light. The photo-system's proficiency relates to the novel ZnO nanocrystals employed. The ZnO carboxylate oligoethylene glycol shell enhances charge separation and accumulates reactive electrons for the photocatalytic process.
Chapter
Most of the information about reaction mechanism comes from chemical kinetics. This chapter first summarizes some of the basic terms related to the kinetic study of chemical reactions, and discusses some examples of chemical reactions in solution, classified according to their reaction order. One of the important sets of parameters obtained from ki...
Article
A chlorinated 2-HNO (2-hydroxynaphthalenoxazoline) was synthesized by an ultrasound-assisted coupling reaction between 1-hydroxy-2-naphthoic acid and L-threonine followed by simultaneous halogenation and cyclization with inversion of configuration using excess SOCl2. Further functionalization of 2-HNO led to a small library of slightly fluorescent...
Article
An expeditious ultrasound–assisted synthesis of a tyrosine–tyrosine peptide library is presented. Dipeptide synthesis and functionalization, via Suzuki-Miyaura or Sonogashira cross-coupling reactions, was carried out and led to sixteen extended conjugation derivatives in moderate to good yields. Both o-hydroxy- and o-methoxy-trans-stilbenyl-Tyr-Tyr...
Article
A scalable and green procedure for the microfluidic flow synthesis of monodisperse silver nanoparticles is reported. Beetroot extract is used both as a reducing and growth-regulating agent. A multi-objective genetic algorithm was used to automate the optimization of the reaction and reduce sample polydispersivity observed in previous reports. The p...
Article
The chemiluminescent decomposition of 1,2-dioxetanones (α-peroxylactones), catalyzed by an appropriate fluorescent activator, is an important simple model for efficient bioluminescent transformations. In this work, we report experimental data on the catalyzed decomposition of two spiro-substituted 1,2-dioxetanone derivatives, which support the occu...
Article
In this work, the study on the influence of binary mixtures of solvents (water-acetonitrile, water-ethanol and water-glycerol) upon the spectroscopic properties of methylene blue (MB) was done. In addition, the photophysical characterization of the MB in different concentrations in the solvent mixtures was done. In the mixtures, the increase in the...
Article
Full-text available
Proline is crucial for energizing critical events throughout the life cycle of Trypanosoma cruzi, the etiological agent of Chagas disease. The proline breakdown pathway consists of two oxidation steps, both of which produce reducing equivalents: the conversion of proline to Δ(1)-pyrroline-5-carboxylate (P5C) and the subsequent conversion of P5C to...
Article
In a proton exchange membrane fuel cell (PEMFC) an aqueous solution containing 100 mg L− 1 of phenol was oxidized at the anode using PtRu/C as catalyst while oxygen gas was reduced at cathode using Pt/C as catalyst. The use of a fuel cell as a flow reactor allowed obtaining hydroquinone, an important compound much used in medicine and cosmetic indu...
Article
Full-text available
The diversity of colors found in the flora results from the interaction of a few classes of pigments with light. Betalains are nontoxic vacuolar pigments that replace anthocyanins in some families of angiosperms and some basidiomycete fungi. There are two classes of betalains: yellow betaxanthins and red betacyanins both biosynthesized from betalam...
Article
Full-text available
Angiotensin II (AII) as well as analog peptides shows antimalarial activity against Plasmodium gallinaceum and Plasmodium falciparum, but the exact mechanism of action is still unknown. This work presents the solid-phase synthesis and characterization of eight peptides corresponding to the alanine scanning series of AII plus the amide-capped deriva...
Article
Full-text available
In this proof-of-concept study, we describe the use of the main red beet pigment betanin for the quantification of calcium dipicolinate in bacterial spores, including Bacillus anthracis. In the presence of europium(III) ions, betanin is converted to a water-soluble, non-luminescent orange 1∶1 complex with a stability constant of 1.4×10(5) L mol(-1)...
Data
Calibration curve for the determination of the [CaDPA] from the variation in absorbance at 536 nm. The y-axis is in the log scale to show the sigmoidal profile of the curve and the linear fitting of the data. Curved lines are the confidence bands at the 95% level. Error bars represent the sd of triplicates. [Bn] = 5.8 µmol L–1, [EuCl3] = 17.4 µmol...
Data
Control experiments for the determination of CaDPA in samples containing spores of B. cereus not submitted to thermal treatment. [Bn] = 5.8 µmol L–1, [EuCl3] = 17.4 µmol L–1 (3 equiv) in MOPS buffer pH = 7.5, N = 1. (TIF)
Data
Effect of the addition of carboxylic acids and phosphate to the [Eu(Bn)]+ complex monitored by the change in the absorption maxima of Bn. [Bn] = 5.8 µmol L–1, [EuCl3] = 17.4 µmol L–1 (3 equiv), [analyte] = 69.6 µmol L–1 (12 equiv) in MOPS buffer pH = 7.5. (TIF)
Data
Quantification of bacteria of the genus Bacillus by the amount of CaDPA released upon thermal treatment for the determination of the amount of CaDPA per spore. The red dotted line is the linear data fitting and the green lines are the confidence bands at 95% confidence level. Vertical and horizontal error bars indicate uncertainties in spore counti...
Data
Spectroscopic data on the [Eu(Bn)]+ complex. (A) Experimental Raman spectra (Ir), second derivative of Raman Intensities relative to wavenumber (d2Ir/dRS2) and theoretical intensities determined the B3LYP/6-31+G(d)/SDM level and corrected by a factor of 0.98 (IrDFT) and optimized structure of Bn; (B) Experimental Raman spectra (Ir), second derivati...
Data
Absorption spectra of [Eu(Bn)]+ in MOPS buffer pH = 7.5 acquired over 5 d and decomposition kinetics monitored at 480 nm, N = 1. (TIF)
Data
Absorption of solutions of Bn and EuIII (536 nm) at a fixed [Bn] = 5.75×10–6 mol L–1. (TIF)
Data
Stability constants determined using Eqs. (1) and (2) and the corresponding concentration of EuIII. (DOCX)
Article
Controlling the dissemination of malaria requires the development of new drugs against its etiological agent, a protozoan of the Plasmodium genus. Angiotensin II and its analog peptides exhibit activity against the development of immature and mature sporozoites of Plasmodium gallinaceum. In this study, we report the synthesis and characterization o...
Article
Full-text available
The decomposition of betanin under dielectric heating (microwave irradiation, power: 25-200 W (3-24 kJ/g) follows first-order kinetics with a rate constant similar to that obtained during conventional conduction heating (half-life < 2 min at 100 degrees C). Color coordinate analysis indicates that betanin is bleached upon thermal treatment, whereas...
Article
Full-text available
The iodine-catalyzed Prins cyclization of homoallylic alcohols and aldehydes was investigated under metal-free conditions and without additives. Anhydrous conditions and inert atmosphere are not required. The reaction of 2-(3,4-dihydronaphthalen-1-yl)propan-1-ol and 21 aldehydes (aliphatic and aromatic) in CH2Cl2 in the presence of 5 mol % of iodin...
Article
This study reports a 48-h aquatic metal-toxicity assay based on daily growth rates of the red seaweed Gracilaria domingensis (Gracilariales, Rhodophyta) in synthetic seawater. The median inhibitory concentration (IC50) for each metal cation was experimentally determined, and the ratios of free ions (aqueous complex) were calculated by software mini...
Article
The induced decomposition of 1,2-dioxetanes results in the efficient formation of singlet-excited carbonyl compounds. This transformation has been assumed to involve two sequential electron-transfer steps and the viscosity dependence of the chemiexcitation efficiency (solvent cage effect) has been considered as an evidence for the occurrence of an...
Article
Full-text available
Betalains are natural antioxidant pigments responsible for the visible fluorescence of flowers. Although these compounds are almost exclusively soluble in water, they are very sensitive to both hydrolysis and water-catalyzed isomerization. We show that three representative betalains are soluble in 2,2,2-trifluoroethanol (TFE) and that the hydrolyti...
Article
The decomposition of betanin under dielectric heating (microwave irradiation, power: 25–200 W (3–24 kJ/g)) follows first-order kinetics with a rate constant similar to that obtained during conventional conduction heating (half-life < 2 min at 100 °C). Color coordinate analysis indicates that betanin is bleached upon thermal treatment, whereas beetr...
Article
Specific ion effects in surfactant solutions affect the properties of micelles. Dodecyltrimethylammonium chloride (DTAC), bromide (DTAB) and methanesulfonate (DTAMS) micelles are typically spherical, but some organic anions can induce shape or phase transitions in DTA+ micelles. Above a defined concentration, sodium triflate (NaTf) induces a phase...
Article
Full-text available
A model betalainic dye was semisynthesized from betanin, the magenta pigment of the red beet, and was effective for live-cell imaging of Plasmodium-infected red blood cells. This water-soluble fluorescent probe is photostable, excitable in the visible region and cell membrane-permeable, and its photophysical properties are not notably pH-sensitive....
Data
Hydrolysis of BtC monitored by UV-Vis absorption spectroscopy or HPLC-DAD analysis. (A) Changes in the absorption spectrum of BtC in aqueous buffer (pH = 7.0) over 66 h and (B) the corresponding kinetic profile; (C) Changes in the chromatographic profile of BtC over 19 h and (D) the corresponding kinetic profile of HBt (red, tR = 1.2 min), BtC (bla...
Data
Normalized absorption (–) and fluorescence emission (····) spectra of C120 (black) and BtC (green) in PBS. (TIFF)
Data
(A) Effect of pH on the absorption and fluorescence spectra of BtC, and (B) dependence of the second-order absorption and emission maxima on the pH. (TIFF)
Data
Fluorescence decay of BtC in water, in isolated P. chabaudi and in P. chabaudi-infected red blood cells. Experiments with parasites were performed with an incubation – centrifugation – washing – resuspension sequence. [BtC] = 50 µmol L–1; EM 570 nm. (TIFF)