Band 9, Heft 8

Ectopeptidases are particularly interesting due to their potential to regulate/dysregulate the peptide mediated signaling cellular pathways because the active site located to the extracellular space. Dipeptidyl peptidase IV (DPP-IV, EC 3.4.14.5) is currently one of the ectopeptidases that has a great and complex influence on important physiological and pathological processes. Due to its influence on the immune system, type 2 diabetes mellitus, pulmonary pathologies, cardiovascular system, viral infections and cancer, DPP-IV is very attractive as a possible therapeutic target. However, its versatility makes such expectations very difficult. The aim of this work is to summarize relevant structural and functional aspects of DPP-IV and the role of this protein in several pathologies with special emphasis on cancer. DPP-IV role in cancer seems to depend on specific location, histologic type of tumour, tumour microenvironment, and presence/absence of molecules able to interact with DPP-IV. Because of DPP-IV controversial effects, generalizations are difficult and most of the time the role of DPP-IV must be analyzed case by case. However, new evidences in cell lines, animal models and clinical studies suggest that DPP-IV inhibitors open a promissory window through new therapeutic strategies against some cancers.

According to a general understanding, a crystal structure is defined by a lattice and the content of the unit cell of this lattice. As consequence a crystal exhibits three-dimensional periodicity with respect to the atoms. However, an increasing number of known crystal structures does not follow this idea of periodicity, but shows an aperiodic arrangement of its atoms. This group of so-called “aperiodic crystals” contains quasicrystals, modulated phases and composite structures. The latter two can be properly described within the higher-dimensional superspace approach to enable an accurate crystal-chemical analysis. Here the superspace is a mathematical tool, in which periodicity can be recovered in a higher-dimensional space. In the first part of this review the basic concept of periodic and aperiodic crystals is presented and similarities and differences of modulated phases, composite structures and quasicrystals are discussed. In a second part the higher-dimensional superspace approach is introduced in reciprocal and in direct space and the implementation of symmetry in superspace is reviewed. In the last part representative examples and the origin of aperiodicity in the crystal structures are discussed.

Verdigris is a collective term for synthetic copper based green and blue pigments that have been used by mankind since the antiquity. As the term is only loosely defined it covers a great variety of chemical compounds. All of them contain copper but also acetate, formate, hydroxide, water and sometimes also chloride, carbonate and sulphate. This article focusses on the verdigris phases related to the ternary system Cu(CH 3 COO) 2 –Cu(OH) 2 –H 2 O, which are commonly denoted according to their chemical composition as x – y – z phases. Besides neutral verdigris (1–0–0 and 1–0–1 phase), several basic verdigris phases (2–1–5, 1–1–5, 1–2–0, 1–3–0, 1–3–2, 1–4–3, 7–1–4) have been reported. These compounds can be obtained either by intentional corrosion of copper metal by direct contact with acetic acid and its vapours, which represents the historic pigment manufacturing or by incomplete precipitation from copper(II) acetate solutions. Due to their slow crystallisation behaviour the synthesis of verdigris pigments usually leads to multiphase and polycrystalline samples, which impedes the phase characterisation, in particular of the basic verdigris samples. Hence, most crystal structures that have been published were solved ab-initio from X-ray powder diffraction data by applying global optimisation methods like simulated annealing or charge flipping . Up to now the crystal structures of the 1–0–0, 1–0–1, 1–3–2, 1–2–0 and 2–1–5 phases were determined, the spectral and physical properties of these compounds completely characterise and therefore their existence and their chemical composition unambiguously proven. Investigations on historic verdigris samples and systematic synthesis approaches, however, show that there are at least four additional, hitherto unknown pigment phases. Information on the thermodynamical stability and the solubility of the verdigris phases are also lacking.

The need for flexible food packaging has increased substantially in recent years around the world due to the unprecedented growth in food consumption. Due to low cost and ease of processing, petroleum-based synthetic polymer packaging materials are being predominantly used for food packaging these days. To avoid contributing to environmental problems caused by ecological risks, consumers have been searching for alternatives to plastic food packaging due to the fact that plastics cannot be recycled and are not biodegradable. Therefore, bioplastics made from corn starch, which are biodegradable, can be one solution to these issues. The starch’s amylopectin and amylase composition has a significant impact on the polysaccharide’s characteristics. Corn starch (CS) is utilized as a food source for humans and other animals, but it also has many other applications in industry. Corn starch, on the other hand, has a few issues that need to be addressed through some modifications. Although starch-based packaging is expensive, they create less waste overall, which helps in the reduction amount of plastic pollution. A variety of natural and synthetic polymers – including polysaccharide-based materials like Kappaphycus alvarezii seaweed, collagen, alginate, chitosan, zein, cellulose, gelatin, various amino acids and polymeric materials like acrylic acid, polybutylene (PB), polyacrylic acid, polyethylene (PE), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), and polycaprolactone (PCL) – are used as starch modifiers to produce polymers with a starch base that are completely biodegradable. These biopolymers have the potential to replacing petroleum-based polymers in a variety of commercial and industrial settings. Besides, corn starch nanocomposite films reinforced with nanocellulose have been investigated as a potential eco-friendly packaging material. Consequently, the effects of nanocellulose content on the mechanical, thermal, and barrier properties of corn starch-based films will be discussed in this work.

Recent researchers are keen on developing alternative bioplastic materials from renewable and eco-friendly sources to replace the materials obtained from crude oil and other petroleum-based sources. The measures for these replacements have been made continuously to create a sustainable future for the forthcoming generations. Researchers are focusing on bio-based alternatives due to their numerous benefits, including biodegradability, biocompatibility, nontoxicity, and structural flexibility. The main problem on the current bio-based material such as poly lactic acid, poly butylene succinate and poly L lactide, polyhydroxybuturate, and polyhydroxyalkalonates is the cost of production. Compare with cassava starch, the cost is much cheaper around 0.32 $/kg compare with other bio-based will cost around 1.2–2.4 $/kg. Conversion of biomass into useful materials has been the order of the day, as it reduces the cost of inventory and aims to develop a nature-derived material. The development of nanocomposites from biological sources has progressively experimented with the researchers and the deriving of polysaccharides such as starch, cellulose, and glycogen has aided the development of nanobiocomposites. Corn starch has been the dominant bioplastic material derived out of corn which can handle a variety of reinforcements and render a biocomposite material with better and enhanced properties. Cassava starch is the most economic and cheap polysaccharide derived from the cassava plant and has a greater potential to act as biopolymer material for the development of biocomposites. The development of cassava starch-based biocomposite film was widely used for a wide range of applications mainly for food packaging applications. This review focuses on the extraction, preparation, and properties of cassava starch from cassava plants. The properties of the cassava starch and its composites were also comprehensively dealt with. The development of biocomposite films based on cassava starch for food packaging applications has been reviewed along with the challenges associated with it.

Food safety and quality are essential concerns for consumers worldwide. One way to ensure that the food we consume meets these standards is through proper food regulation. While there are various aspects of food regulation, one critical aspect is the regulations for food packaging materials. As such, this book chapter has been written to provide an in-depth overview of the regulations for food packaging materials in different continents, namely Asia, Europe, and America. The chapter delves into several countries in each continent, such as Malaysia, Japan, Australia, China, the United States, and South Africa, and discusses their specific food packaging regulations. This chapter also emphasizes the importance of considering the composition, migration properties, and potential for contamination of food packaging materials. It highlights the need for regulations to ensure that food packaging materials do not adversely affect the safety and quality of food products. In light of the evolving food packaging industry, the chapter further underscores the need for continuous evaluation and improvement of food packaging regulations. This is crucial to keep up with emerging risks and new technologies that may arise and impact the safety and quality of food.

The application potential of enzymes is undoubtedly very high. However, despite the very large number of different enzymes and enzyme activities, the number of industrial enzyme processes is comparatively small. The particular challenge often lies in transferring promising laboratory processes to an industrial scale. Here, the required performance parameters, such as enzyme stability or productivity, must be achieved. On the one hand, this can be achieved by improving the enzymes. On the other hand, the key performance indicators can often only be achieved by using technical systems in the sense of process intensification. In enzymatic processes, immobilization of enzymes is often the means of choice to enable technical processes. The aim of this article is to outline the most important enzyme immobilization methods and to summarize the most important performance indicators of immobilized enzymes. Finally, the different immobilization methods and performance indicators are compared in a case study with unspecific peroxygenase.

Succinic acid is a valuable organic acid with a high commercial value that may be employed in a variety of sectors including food, cosmetics, and chemistry. Through bacterial fermentation, succinic acid can be easily produced. This paper includes a broad body of literature assessment spanning the previous two decades on the evaluation of succinic acid (SA) production procedures in to further drive research toward membrane-based sustainable and affordable production. The best natural method of SA producer is through Actinobacillus succinogenes. The process of microbial fermentation is used to produce bio-succinic acid utilizing agro-industrial waste. There are different methods under metabolic engineering which are being frequently used for bio-based succinic acid production using representative microorganisms, such as Mannheimia succiniciproducens, Pichia kudriavzevii, Saccharomyces cerevisiae, Actinobacillus succinogenes, Corynebacterium glutamicum, Basfia succiniciproducens, and Escherichia coli. This review summarizes the evolution of microbial production, fermentative methods, various organic substrates and the effects of efforts to recover and refine components for a wide range of applications in the perspective of biologically produced succinic acid for commercialization state.

Both biotechnological and electrochemical processes have economic and environmental significance. In particular, biotechnological processes are very specific and stable, while electrochemical processes are generally very atom-and energy-efficient. A combination of these processes is therefore a potentially important approach to intensify biotechnological processes. In this paper, the relevant options for process integration are presented, key performance indicators for quantitative evaluation are given, and an evaluation based on performance indicators is carried out using the example of the electrochemical reduction of CO 2 to formate and the subsequent biotechnological conversion to the biopolymer polyhydroxybutyrate.

Sustainable and intelligent solutions are required to address the issues brought about by anthropogenic activity and the restricted availability of resources. Every nation is attempting to use each product from a natural resource in a necessary way in light of the current rise in environmental awareness. The bio-based biopolymers can be made from bacteria, animals, or plants. Biopolymers are a diverse class of compounds that are either produced by biological systems or synthesized from biological resources. Biopolymers are categorized as biodegradable and nonbiodegradable. Based on origin, they are further classified as being either bio based or fossil fuel based. Recently, biopolymers have gained immense recognition in different areas of biomedical field such as wound healing, burn dressing, tissue engineering, and fungal infection. These biodegradable polymer composites are effective at containing and releasing bioactive medications, such as probiotics, enzymes, pharmaceuticals, and nutraceuticals. Moreover, medicinal plants, a rich source of phytochemicals have been extensively used for their various therapeutic activities since ancient times and are being steadily providing the basis in modern drug delivery systems. There has been a lot of interest in the detection, separation, and use of dietary phytochemicals that may enhance human health and act as natural pigments, antioxidants, or antimicrobials well-being by preventing chronic illnesses like cancer, diabetes, obesity, and cardiovascular disorders. However, the delivery of these compounds for enhanced efficacy requires a rational approach. Therefore, the present chapter discuss about various sources of biopolymer, challenges, their construction mechanism, and their conjugation with phytochemicals as well as their applications.