João Paulo André

University of Minho · Departamento de Química (DQ)

Until the twelfth century, several European nuns achieved a high level of erudition, prestige, and authority. Among them, Hildegard of Bingen, a German abbess, stood out as one of the most cultivated figures of her time, displaying extensive knowledge in natural philosophy and medicine. As universities emerged in Europe, gradually supplanting monas...

In the early days, obtaining a university degree as a young woman did not necessarily guarantee a carefree future. When universities began admitting women, little or no consideration had been given to potential careers for female students. Some institutions did not even issue diplomas to them. While a minority of students could afford to do nothing...

Sixteenth-century Italy was rich in books of “secrets.” Among these works, Giambattista della Porta’s Magia Naturalis stands out as one of the best models. These compilations consisted of recipes, formulations, and practical advice covering various subjects like natural philosophy, astrology, medicine, alchemy, cosmetics, cooking, and occultism. Da...

The main focus of this chapter is Ellen Swallow Richards, an American who, in 1870, became the first woman to enroll at the Massachusetts Institute of Technology (MIT), in Boston. As an instructor in Sanitary chemistry at that institution, she had a remarkable and diverse scientific career, despite not obtaining a doctoral degree. Richards advocate...

The history of women’s involvement in activities related to chemical processes can be traced back to ancient times, primarily in the domains of food preparation and preservation. Women likely played roles in early pottery and in the conversion of ores into metals. They were also responsible for preparing remedies, and with the development of the ea...

The possibility for women to acquire technical skills and academic qualifications has been closely followed by their desire to integrate into professional and scientific societies. Predictably, this did not come without its challenges. In England, concerning the Chemical Society, this only became possible from 1920 onwards, after a 40-year struggle...

The authors of a recent article titled “The Mutation of the ‘Nobel Prize in Chemistry’ into the ‘Nobel Prize in Chemistry or Life Sciences,’” published in the prestigious journal Angewandte Chemie International Edition, draw attention to the influence of non-scientific factors—specifically gender, ethnicity, and nationality—on the Nobel Prize award...

As a reaction to the Renaissance, throughout the seventeenth century, mathematics replaced magic in interpreting natural phenomena, and mechanical philosophy gradually supplanted organicism. These changes paved the way for the dissemination of atomism, which had originated in Greece in the fifth century BC but had fallen into oblivion until it expe...

During the Enlightenment, chemistry continued to position itself as a practical discipline rather than a theoretical one. Benefiting from centuries-old alchemical techniques and instruments, and simultaneously distancing themselves from the enigmatic speculations of the past, chemists directed their skills toward the preparation of useful products...

Nowadays, some institutions encourage scientific partnerships between spouses. In the not-too-distant past, some universities viewed such collaborations as nepotism, albeit a way to save on salaries, as it was almost certain that wives would collaborate with their husbands. For a woman aspiring to pursue a career in science and having a researcher...

The United States of America, a nation that embraced the core principles of the Enlightenment, swiftly established a system of universal education. This system provided convenient access to colleges and higher education for its female population. Chemistry, recognized for its societal, domestic, and intellectual significance, has consistently held...

Despite the prevailing barriers to acquiring a formal education, eighteenth-century women had access to a variety of textbooks tailored to disseminate knowledge of natural philosophy. Often perceived as having fragile minds, these women only needed minimal knowledge of the era’s progress. Titles such as Astronomy of the Ladies, Newtonianism for Lad...

The German-born Fredrick Accum (1769-1838), lecturer, author, analyst, industrial chemist, technical expert and trader of chemicals and apparatus was once one of the best-known scientists in the United Kingdom. His efforts to popularize chemistry and to bring it to people of all classes were highly successful as demonstrated by the large audiences...

Three triaza macrocyclic ligands, H6NOTP (1,4,7-triazacyclononane-N,N',N″-trimethylene phosphonic acid), H4NO2AP (1,4,7-triazacyclononane-N-methylenephosphonic acid-N',N″-dimethylenecarboxylic acid), and H5NOA2P (1,4,7-triazacyclononane-N,N'-bis(methylenephosphonic acid)-N″-methylene carboxylic acid), and their gallium(III) chelates were studied in...

Three PEGylated derivatives of 6-amino-2-[4,7,10-tris(carboxymethyl)-1,4,7,10-tetrazacyclododec-1-yl]hexanoic acid (DOTA-AHA) with different molecular weights were prepared and characterized. Their GdIII chelates were studied in aqueous solution through variable-temperature 1H nuclear magnetic relaxation dispersion (NMRD) and 17O NMR spectroscopy t...

The cover picture showsthe general structure of several PEGylated DOTA-based gadolinium(III) chelates developed as potential contrast agents for magnetic resonance imaging (MRI). The rotating arrow presented over the full-body MRI image illustrates the importance of the tumbling behavior of the chelates for their relaxivity. These chelates present...

Three PEGylated derivatives of 6-amino-2-[4,7,10-tris(carboxymethyl)-1,4,7,10-tetrazacyclododec-1-yl]hexanoic acid (DOTA-AHA) with different molecular weights were prepared and characterized. Their GdIII chelates were studied in aqueous solution through variable-temperature 1H nuclear magnetic relaxation dispersion (NMRD) and 17O NMR spectroscopy t...

The need for magnetic resonance imaging (MRI) contrast agents with improved relaxivity maintains the development of new GdIII chelates as an intensive and demanding field of research. In this work, we introduce the new dimeric chelators bis{1,4,7,10-tetraazacyclododecane-1-[(6-amino)hexanoic]-4,7,10-triacetic acid}adipate [L2, bis(DOTA-AHA)adipate]...

Artistic creation has always reflected the 'spirit of the moment, and opera has not been an exception. There are several examples of operas that appeared at key moments of the development of science, portraying them. Additionally, there are also operas that emerged after scientific events or the lifetime of the scientists by whom they were inspired...

The availability of commercial (68)Ge/(68)Ga cyclotron-independent (68)Ga(3+) generators is making Positron Emission Tomography (PET) accessible to most hospitals, which is generating a surge of interest in the design and synthesis of bi-functional chelators for Ga(3+). In this work we introduce the NO2A-N-(α-amino)propionic acid family of chelator...

The storyline of operas, with historical or fictional characters, often include potions and poisons. This has prompted a study of the chemistry behind some operatic plots. The results were originally presented as a lecture given at the University of Minho in Portugal, within the context of the International Year of Chemistry. The same lecture was s...

Due to its favorable relaxometric properties, Mn(2+) is an appealing metal ion for magnetic resonance imaging (MRI) contrast agents. This paper reports the synthesis and characterization of three new triazadicarboxylate-type ligands and their Mn(2+) chelates (, 1,4,7-triazacyclononane-1,4-diacetate-7-heptanil; , 1,4,7-triazacyclononane-1,4-diacetat...

In this work, we report on a synthetic strategy using amphiphilic DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid)-based chelators bearing a variable-sized α-alkyl chain at one of the pendant acetate arms (from 6 to 14 carbon atoms), compatible with their covalent coupling to amine-bearing biomolecules. The amphiphilic behavior of th...

We report a straightforward and efficient synthetic strategy for the synthesis of three model glycine-arginine-glycine-aspartic acid-glycine (GRGDG) conjugates based on derivatives of NOTA and of their Ga(III) complexes targeted to the integrin α(ν)β(3) receptor. (71)Ga NMR spectroscopy showed that the Ga(III)-labeled conjugates are highly stable i...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Radiogallium chelates are important for diagnostic imaging in nuclear medicine (PET (positron emission tomography) and gamma-scintigraphy). Micelles are adequate colloidal vehicles for the delivery of therapeutic and diagnostic agents to organs and tissues. In this paper we describe the synthesis and in vitro and in vivo studies of a series of mice...

The recently reported amphiphilic chelate, [Gd(EPTPAC(16))(H2O)](2-), forms supramolecular aggregates in aqueous solution by self-assembly of the monomers with a relaxometrically determined critical micellar concentration (CMC) of 0.34mM. The effect of sonication on the aggregate size was characterized by dynamic light scattering and relaxometry, i...

PET (positron emission tomography) is a powerful diagnostic and imaging technique which requires short-lived positron emitting isotopes. The most commonly used are accelerator-produced (11)C and (18)F. An alternative is the use of metallic positron emitters. Among them (68)Ga deserves special attention because of its availability from long-lived (6...

Somatostatin-based radioligands have been shown to have sensitive imaging properties for neuroendocrine tumours and their metastases. The potential of [(55)Co(dotatoc)] (dotatoc =4,7,10-tricarboxymethyl-1,4,7,10-tetraazacyclododecane-1-ylacetyl-D-Phe-(Cys-Tyr-D-Trp-Lys-Thr-Cys)-threoninol (disulfide bond)) as a new radiopharmaceutical agent for PET...

The synthesis and characterization of a new metal chelator, 4-(S)-hydroxymethyl-3,6,10-tri(carboxymethyl)-3,6,10-triazadodecanedioic acid (H5EPTPACH2OH), is reported. Protonation constants for the ligand H5EPTPACH2OH and for the previously reported H5EPTPAC16 have been determined by potentiometry, which reveals that both ligands display slightly hi...

Positron emission tomography (PET) is becoming a dominating method in the field of molecular imaging. Most commonly used radionuclides are accelerator produced 11C and 18F. An alternative method to label biomolecules is the use of metallic positron emitters; among them 68Ga is the most promising as it can be produced from a generator system consist...

The characterization of a new class of hydrophilic liver-targeted agents for gamma-scintigraphy and MRI, consisting, respectively, of [(153)Sm](3+) or Gd(3+) complexes of DOTA monoamide or bisamide linked glycoconjugates (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid), is reported. In vitro studies show high uptake of radiolabeled...

We report the synthesis and characterization of the novel ligand H(5)EPTPA-C(16) ((hydroxymethylhexadecanoyl ester)ethylenepropylenetriaminepentaacetic acid). This ligand was designed to chelate the Gd(III) ion in a kinetically and thermodynamically stable way while ensuring an increased water exchange rate (kappa(ex)) on the Gd(III) complex owing...

The synthesis and characterisation of a new class of DTPA bis(amide) linked glycoconjugates of different sugars [lactose (Lac) and galactose (Gal)] and valencies (di and tetra) and their LnIII complexes is reported. The 1H NMR spectra of the SmIII and EuIII complexes of DTPAGal2, DTPAGal4, and DTPALac2, obtained between 7 and 80 °C, indicate that s...

The ligand H5dotasa (=(αRS)-α-(carboxymethyl)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) is a H4dota-like macrocyclic ligand with a carboxymethyl CH2COOH substituent at the C(α) atom of one of the four acetate pendant arms of H4dota (=1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid), present as a racemic mixture of (αR) and...

The synthesis and characterization of a new class of DOTA (1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecane) monoamide-linked glycoconjugates (glucose, lactose and galactose) of different valencies (mono, di and tetra) and their Sm(III), Eu(III) and Gd(III) complexes are reported. The 1H NMR spectrum of Eu(III)-DOTALac2 shows the pre...

In spite of the fact that Group 13 metal ions (Al(3+), Ga(3+), In(3+) and Tl(+/3+)) show no main biological role, they are NMR-active nuclides which can be used in magnetic resonance spectroscopy of biologically relevant systems. The fact that these metal ions are quadrupolar (with the exception of thallium) means that they are particularly sensiti...

The metallic radioisotope of a known radiopharmaceutical chelate, (67)Ga(NOTA) (NOTA=1,4,7-triazacyclonane-1,4,7-triacetic acid), used for tumor detection, was substituted by the chemically similar but non radioactive aluminum ion. Our aim was to detect and evaluate the in vivo behavior of the chelate. For this purpose, Al(NOTA) and the related che...

With the aim of obtaining a high-relaxivity MRI contrast agent, we have designed a new amphiphilic GdIII chelate that is capable of self-organization by forming micelles in aqueous solution. The synthesis of the [GdL-(H2O)]- complex is straightforward and offers an easy way for modification (L = 1,4,7,10-tetraazacyclododecane-1-(1′-carboxy-1′-dodec...

The ligand DOTASA was designed and synthesized in the aim of obtaining a kinetically and thermodynamically stable Gd(III) chelate which, through its uncoordinated carboxylate function, will provide an efficient pathway to couple the complex to bio- or macromolecules without affecting the coordination pattern of DOTA. Furthermore, it allows us to st...

A new bifunctional chelator NODASA (1,4,7-triazacyclononane-1-succinic acid-4,7-diacetic acid) has been synthesised, its kinetically inert gallium(III) complex was crystallographically characterized and conjugated to a model aminoacidamide showing the feasibility of a prelabelling approach with 68,67Ga.

The macrocyclic ligand DO2A (1,4,7,10-tetraazacyclododecane-1,7-bis(acetic acid)) was prepared and used as a building block for four new macrocyclic ligands having mixed side-chain chelating groups. These ligands and their complexes with Mg(II), Ca(II), and Ln(III) were studied extensively by potentiometry, high-resolution NMR, and water proton rel...

Complexation of europium(III) with glyceryl-1- and -2-phosphates has been studied by metal ion luminescence, 1H and 13C NMR spectroscopy and potentiometry. From the luminescence and NMR studies, the formation of a 1:1 inner-sphere complex, in which the glyceryl phosphate is directly bound to the metal, is confirmed. Similar apparent binding constan...