Despite the impressive progress in nucleoside chemistry to date, the synthesis of nucleoside analogues is still a challenge. Chemoenzymatic synthesis has been proven to overcome most of the constraints of conventional nucleoside chemistry. A purine nucleoside phosphorylase from Aeromonas hydrophila (AhPNP) has been used herein to catalyze the synthesis of Ribavirin, Tecadenoson, and Cladribine, by a “one-pot, one-enzyme” transglycosylation, which is the transfer of the carbohydrate moiety from a nucleoside donor to a heterocyclic base. As the sugar donor, 7-methylguanosine iodide and its 2′-deoxy counterpart were synthesized and incubated either with the “purine-like” base or the modified purine of the three selected APIs. Good conversions (49–67%) were achieved in all cases under screening conditions. Following this synthetic scheme, 7-methylguanine arabinoside iodide was also prepared with the purpose to synthesize the antiviral Vidarabine by a novel approach. However, in this case, neither the phosphorolysis of the sugar donor, nor the transglycosylation reaction were observed. This study was enlarged to two other ribonucleosides structurally related to Ribavirin and Tecadenoson, namely, Acadesine, or AICAR, and 2-chloro-N⁶-cyclopentyladenosine, or CCPA. Only the formation of CCPA was observed (52%). This study paves the way for the development of a new synthesis of the target APIs at a preparative scale. Furthermore, the screening herein reported contributes to the collection of new data about the specific substrate requirements of AhPNP.

A soy protein isolate was hydrolyzed with Alcalase^®, Flavourzyme^® and their combination, and the resulting hydrolysates (A, F and A + F) were ultrafiltered and analyzed through SDS-PAGE. Fractions with MW < 1 kDa were investigated for their ACE-inhibitory activity, and the most active one (A < 1 kDa) was purified by semi-preparative RP-HPLC, affording three further subfractions. NMR analysis and Edman degradation of the most active subfraction (A1) enabled the identification of four putative sequences (ALKPDNR, VVPD, NDRP and NDTP), which were prepared by solid-phase synthesis. The comparison of their ACE-inhibitory activities suggested that the novel peptide NDRP might be the main agent responsible for A1 fraction ACE inhibition (ACE inhibition = 87.75 ± 0.61%; IC₅₀ = 148.28 ± 9.83 μg mL⁻¹). NDRP acts as a non-competitive inhibitor and is stable towards gastrointestinal simulated digestion. The Multiple Reaction Monitoring (MRM) analysis confirmed the presence of NDRP in A < 1 kDa.

Biocatalysis has emerged in the last decade as a valuable and eco‐friendly tool in chemical synthesis, allowing in several instances to reduce or eliminate the use of hazardous reagents, environmentally dangerous solvents and harsh reaction conditions. Enzymes are indeed able to catalyse chemical transformations on non‐natural substrates under mild reaction conditions, still maintaining their high chemo‐, regio‐, and stereoselectivity. Enzyme immobilization, i. e. the grafting of enzymes on solid supports, can be viewed as an enabling technology, as it allows a better control of the reaction and the recycling of the biocatalyst, thus rendering economically viable the use of expensive enzymes also on a large scale. To pursue a sustainable approach, the supports for enzyme immobilization should be eco‐friendly and possibly renewable. This review highlights the use of hydroxyapatite (HAP), an inorganic biomaterial able to confer strength and stiffness to the bone tissue in animals, as carrier for enzyme immobilization. HAP is a cheap, non‐toxic and biocompatible material, with high surface area and protein affinity. Different enzyme classes, immobilization strategies, and the use of diverse HAP‐based supports will be discussed, underlining the immobilization conditions and the properties of the obtained biocatalysts.

A library of alkyl galactosides was synthesized to provide the “polar head” of sugar fatty acid esters to be tested as non‐ionic surfactants. The enzymatic transglycosylation of lactose resulted in alkyl β‐D‐galactopyranosides, whereas the Fischer glycosylation of galactose afforded isomeric mixtures of α‐ and β‐galactopyranosides and α‐ and β‐galactofuranosides. n‐Butyl galactosides from either routes were enzymatically esterified with palmitic acid, used as the fatty acid “tail” of the surfactant, giving the corresponding n‐butyl 6‐O‐palmitoyl‐galactosides. Measurements of interfacial tension and emulsifying properties of n‐butyl 6‐O‐palmitoyl‐galactosides revealed that the esters of galactopyranosides are superior to those of galactofuranosides, and that the enantiopure n‐butyl 6‐O‐palmitoyl‐β‐D‐galactoside, prepared by the fully enzymatic route, leads to the most stable emulsion. These results pave the way to the use of lactose‐rich cheese whey as raw material for the obtainment of bio‐based surfactants.

Esters ofsn‐glycero‐3‐phosphoric acid (GPAE) are derivatives of glycerophospholipids in which both the fatty acid chains insn‐1 andsn‐2 positions are removed. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidylserine (PS) are the most abundant glycerophospholipids in Nature. Their deacylated derivatives find application in many industrial sectors; for example,sn‐glycero‐3‐phosphocholine (GPC) is useful as a cognitive enhancer and as a food ingredient, whereassn‐glycero‐3‐phosphoinositol (GPI) acts as a natural anti‐inflammatory agent. This minireview covers the state‐of‐the‐art of chemical and biocatalytic methods for the obtainment of these lipid‐derived components.

Umami taste, known as appetizing sensation, is mainly imparted by monosodium glutamate (MSG, the first identified umami factor) in synergistic combination with some 5′ ribonucleotides such as inosine 5′‐monophosphate, IMP, guanosine 5′‐monophosphate, GMP, and adenosine 5′‐monophoshate, AMP. The level of free glutamic acid in tomatoes is higher than in other vegetables or fruits and increases with ripening and industrial processing. In addition, due to the presence of bioactive metabolites, tomatoes and tomato‐based products are among the most consumed healthy food items. The levels of the major umami compounds of tomato, that is, glutamate and 5′‐ribonucleotides (GMP and AMP) were assessed in different parts (skin, outer flesh, and inner pulp) of known tomato varieties from southern Italy: San Marzano Originale, San Marzano 245, Black Tomato, Corbarino Corbara, Corbarino Nocera, and Superpomodoro (tomato hybrid). Such varieties were also investigated for their antioxidant properties through DMPD, DPPH, and ABTS assays, with San Marzano Originale showing the highest antioxidant power both in lipophilic and methanolic fractions. The concentration of umami compounds in tomato differs with the part of the fruit analyzed and is greatly dependent on the variety, being Corbarino Nocera the cultivar richest in glutamate and Superpomodoro in ribonucleotides. As for nutritional aspect, results confirm the great nutraceutical feature of San Marzano tomato, the most known variety used in industrial processes. Practical applications This study was planned to develop a method to quantify the major umami compounds that strongly influence the organoleptic properties of many different tomato varieties. It is known that the sensory quality of fruits and vegetables is an important factor in consumer's choice. The analytical methods described here enabled the evaluation of the glutamate and 5′‐ribonucleotides contents in six selected varieties of tomato from Campania region, and can be easily used to determine the sensory profile of commercial varieties, for example, those perceived as not very tasteful by consumers.