Volume 4, Issue 8 -

Catalysis is, often, the preferred approach to access chiral molecules in enantioenriched form both in academia and in industry; nowadays, organocatalysis is recognised as the third pillar in asymmetric catalysis, along with bio- and metal-catalysis. Despite enormous advancements in academic research, there is a common belief that organocatalysis is not developed enough to be applicable in industry. In this review, we describe a selection of industrial routes and their R&D process for the manufacture of active pharmaceutical ingredients, highlighting how asymmetric organocatalysis brings added value to an industrial process. The thorough study of the steps, driven by economic stimuli, developed and improved chemistry that was, otherwise, believed to not be applicable in an industrial setting. The knowledge discussed in the reviewed papers will be an invaluable resource for the whole research community.

Illuminated manuscripts are the most abundant and well-preserved surviving medieval cultural artefacts. Created to contain sacred texts, their visual structure allows the reader to identify divisions and delight in their beautiful ornamentation and iconography. Western European manuscripts were written on parchment, which was the main writing support in the Middle Ages prior to the rise of paper production in the fourteenth–fifteenth centuries. Highly functional, durable animal skins were also used in medieval bookbinding (covers) and have been crucial in the preservation of the illuminations. These illuminations make wonderful use of form and colour. This chapter focuses on recent advances in the molecular characterization of these colours, used in medieval manuscripts produced by Western Europeans, and the challenges inherent in analysing materials that are intrinsically heterogeneous. We then discuss how molecular characterization may reveal conservation conditions and extend our analysis to parchment and iron gall inks. Finally, we address the challenges and possibilities for this flourishing field of research. In short, we show in this chapter how analytical methods are used: – To understand how medieval illumination colours were made and what palette defines them; – To predict original colours and to understand why certain colours have remained in excellent condition, preserving both adherence and luminosity, while others have changed over the centuries; – To assess deterioration (paints, parchment, writing inks) with the goal of determining what potential restoration measures could be taken, after careful consideration.

The first part of this chapter provides an overview of computer-based tools (algorithms, web servers, and software) for the prediction of bitterness in compounds. These tools all implement machine learning (ML) methods and are all freely accessible. For each tool, a brief description of the implemented method is provided, along with the training sets and the benchmarking results. In the second part, an attempt has been made to explain at the mechanistic level why some medicinal plants are bitter and how plants use bitter natural compounds, obtained through the biosynthetic process as important ingredients for adapting to the environment. A further exploration is made on the role of bitter natural products in the defense mechanism of plants against insect pest, herbivores, and other invaders. Case studies have focused on alkaloids, terpenoids, cyanogenic glucosides and phenolic derivatives.

This survey shows how colorants are not only ubiquitous in modern life, but also pervade many fields of science and technology. It reveals their diversity with respect to properties, origin of color, applications, composition and usage. After opening with a technical definition of “colorant”, this survey exemplifies the huge assortment of uses to which colorants are put. It highlights the breadth of characteristics, other than color, that are of importance to the roles of “functional colorants”. Following a description of the technical distinction between the terms “dye” and “pigment”, the survey discusses the differences between these two colorant types from the perspective of how their color arises and the ways in which they are exploited, then goes on to demonstrate that particular colorants may be applied in certain instances as a dye and in others as a pigment. It outlines the wide ranges of composition, properties and economics of commercial colorants. This survey closes with a look at the nomenclature of colorants and the means by which they are classified into practically useful categories. It is intended to prepare the reader for the enormous technical and commercial variety that one encounters when dealing generally with colorants.

The techniques of chemical investigation by X-ray fluorescence (XRF) are widespread since the 50s of the last century. Depending on the accuracy of the desired data and on the artifact characteristics, they can be used as partially destructive or as absolutely non-destructive and non-invasive techniques. The archeomaterials that can be analyzed are the most disparate: minerals, rocks, metals, building materials, pigments, and so on; practically almost everything that is solid, liquid or gelatinous can be analyzed by XRF. The theoretical physical principles and the main components of X-ray spectrometers, in energy dispersion (ED) and wavelength dispersion (WD), are described, also comparing the advantages and disadvantages of each analytical technique. In the last decades, the diffusion of the ED silicon drift detectors, together with the development of very accurate and high specialized software for quantitative analysis, has given a new impulse to the diffusion of the portable spectrometers offering new possibilities for in situ and very rapid archeomaterial characterizations. Case studies related to different artworks, like ceramics, necklaces, coins, obsidians and other lithic artifacts will also be presented: they show the important contribution that X-ray spectrometer technique gives to solve problems related to the characterization, restoration and to the source identification of the raw materials.