Search Results (198)

3′-sialyl-N-acetyllactosamine (3′-SLN) and 6′-sialyl-N-acetyllactosamine (6′-SLN) are two important human milk oligosaccharides (HMOs) which play significant functions in brain development and antiviral potential. However, their metabolism is still unknown. In this study, chemoenzymatically synthesized 3′-SLN and 6′-SLN were labeled with cyanine-7 (Cy7) via formation triazole (Tz) derivatives to investigate their metabolism and organ distribution in a mouse model. The fluorescence signals were detected in the brains of mice after 0.5 h of gavage with 3′-SLN-Tz-Cy7 and 6′-SLN-Tz-Cy7. It was found for the first time that both of them can cross the blood–brain barrier (BBB) as a whole and reach the brain in a sex-specific manner. And the results show that, whether in the in vivo imaging results or the brain fluorescence signal results, the male mice absorbed 3′-SLN-Tz-Cy7 more than 6′-SLN-Tz-Cy7; meanwhile, in the female mice, the results were exactly the opposite. Both 3′-SLN-Tz-Cy7 and 6′-SLN-Tz-Cy7 exhibited the highest fluorescence intensity in pulmonary tissues, followed by substantial hepatic deposition. This study would offer preliminary evidence for the hypothesis that the oral administration of 3′-SLN and 6′-SLN may promote brain development and provide a foundation for the further exploration of their functions in brain cognition. Full article

Nicotinic acid adenine dinucleotide phosphate (NAADP) is a second messenger that stimulates intracellular Ca²⁺ release in both mammalian cells and echinoderm egg homogenates. A NAADP linked covalently to a stable long-wavelength fluorescent dye would be a useful probe with which to characterize NAADP–receptor interactions in solution and potentially to determine intracellular-binding localization. We report the synthesis of a BODIPY-NAADP covalent conjugate made through linking the carboxyl group of BODIPY FL to the primary amino group of 5-(3-aminopropyl)-NAADP through amide bond formation. The starting pyridine dinucleotide analog, 5-(3-aminopropyl)-NAADP was available through enzyme-catalyzed base exchange between NADP and a substituted nicotinic acid analog. The resulting 5-BODIPY-NAADP conjugate was purified to homogeneity using ion-exchange chromatography, was produced in milligram quantities, and its spectroscopic properties were characterized. Full article

Nitrile-containing compounds are integral to pharmaceuticals, agrochemicals and polymer industries, yet their environmental persistence and toxicity pose major challenges. Biocatalytic approaches using nitrile-converting enzymes—particularly nitrilases and nitrile hydratases—offer sustainable alternatives to conventional hydrolysis, enabling the selective transformation of nitriles into amides and acids under mild conditions. This review presents an industrial perspective on nitrile-converting enzymes, summarising their catalytic potential, current limitations, and emerging strategies for stability, activity and performance enhancement. Advances in protein engineering, metagenomic discovery and biocatalytic optimisation have already expanded their wider applicability, while synthetic biology and protein design tools are accelerating the development of tailored biocatalysts. The integration of these enzymes into cascades and chemoenzymatic processes supports scalable and innovative solutions to green manufacturing. Collectively, these emerging strategies position nitrile-converting enzymes as versatile tools for sustainable catalysis, with growing relevance in fine chemical synthesis, waste remediation, and bio-based synthetic platforms. Full article

Chimeric compounds represent a promising strategy in cancer therapy by simultaneously targeting multiple pathways responsible for tumour growth and survival. Their structure comprises two or more pharmacophores connected through suitable chemical linker. These dual or multi-functional drugs can interact with several biological targets for a more pronounced pharmacological effect. In order to identify new multi-targeting agents with anticancer efficacy, we designed and synthesised a series of novel multi-functional molecules by covalently linking antitumor compounds dichloroacetate (DCA) and Nutlin-3a. The design was aimed at addressing two critical events in cancer: (1) the Warburg effect and (2) the dysregulations of protein p53 pathway, both of which are directly linked to the predominant survival and aggressive proliferation of malignant cells. DCA reactivate oxidative phosphorylation by inhibiting mitochondria pyruvate dehydrogenase kinase (PDK), thereby unlocking the Warburg metabolism of cancer cells and its antiapoptosis state. Concurrently, Nutlin-3a restores the protective function of the “genome guardian” p53 protein, by blocking its antagonist oncoprotein E3 ligase MDM2. Chimeric compounds were obtained using a chemoenzymatic multi-step procedure that included a key lipase-catalysed asymmetric reaction. Biological evaluation of the synthesised Nutlin-DCA chimeras in a panel of three cancer cell lines demonstrated promising results in vitro. Specifically, compounds rac-19a, rac-19b, rac-20a, rac-20b and enantioenriched 20a caused a statistically significant reduction in cell viability at micromolar concentrations. These findings suggest that targeting both the Warburg effect and the p53 pathway with a single molecule is a viable approach for future cancer therapeutic development. Full article

This review overviews the efficient hydrophobization method of hydrophilic natural polymers, which has been developed by means of glucan phosphorylase (GP)-induced enzymatic grafting of unnatural heteropolysaccharides, that is, partially 2-deoxygenated (P2D)-amyloses. The enzymatic polymerization technique is well known as a useful approach to prepare polysaccharides with well-defined structures. The authors have found that the hydrophobicity of P2D-amylose, synthesized by the thermostable GP (from Aquifex aeolicus VF5)-induced enzymatic copolymerization of α-d-glucose 1-phosphate (Glc-1-P)/d-glucal as comonomers, started from maltooligosaccharide primers. Based on this finding, glycogen, a hydrophilic spherical natural polysaccharide, was hydrophobized by means of the thermostable GP-induced enzymatic functionalization of the P2D-amylose chains because glycogen acted as the polymeric primer for the GP catalysis. After introducing the maltooligosaccharide primers onto hydrophilic natural polymers with carboxylate groups—such as poly(γ-glutamic acid), carboxymethyl cellulose, and alginic acid—via chemical reactions, the thermostable GP-induced enzymatic copolymerization of Glc-1-P/d-glucal was carried out using the resulting polymeric primers, enabling their hydrophobization through the grafting of P2D-amylose chains (the chemoenzymatic approach). Moreover, the chemoenzymatic method has extensively been employed for hydrophobization of the surfaces on natural polysaccharide nanofibers, such as cellulose and chitin nanofibers. Full article

Resveratrol is a natural stilbene known for its wide range of biological activities, including antioxidant, anti-inflammatory, and anti-aging effects. However, its application in cosmetics and dermatology is limited by poor stability and bioavailability. Azelaic acid is a natural carboxylic acid employed in cosmetics for its tyrosinase inhibition activity and for cutaneous hyperpigmentation disorders. In this work, we report a concise chemoenzymatic procedure for the synthesis of a novel hybrid molecule combining acetylated resveratrol and azelaic acid. This methodology offers a valuable route for the development of new bioactive compounds for potential cosmetic and dermatological applications. Full article

Human applications of surfactants have been diverse, from their initial use as detergents to their subsequent utilization in a multitude of other fields, including medicine, lubricants, cosmetics, and even assisted oil recovery. Nevertheless, the most significant challenge lies in the synthesis of surfactants. A particular challenge is the purification of compounds following chemical synthesis, as well as the toxic effect of the solvents used. Consequently, there is a growing need for more environmentally friendly solutions, namely solvents that are less toxic and more biocompatible, as well as reactions in which an enzyme serves as a catalyst. This review examines the various methods of synthesizing sugar esters and glycolipids, evaluating their respective advantages and disadvantages. Full article

A series of new 3′-deoxyribosides of substituted benzimidazoles was obtained by the chemo-enzymatic method using genetically engineered E. coli purine nucleoside phosphorylase (PNP). In the case of asymmetrically substituted benzimidazole derivatives, a mixture of N1- and N3-regioisomers was formed (confirmed by NMR). The antiviral activity of the obtained compounds against herpes simplex virus 1 of reference strain L2 and a strain deeply resistant to acyclovir in Vero E6 cell culture was studied. 4,6-Difluoro-1-(β-D-3′-deoxyribofuranosyl)benzimidazole (IC₅₀ = 250.92 µM, SI = 12.00) and 4,5,6-trifluoro-1-(β-D-3′-deoxyribofuranosyl)benzimidazole (IC₅₀ = 249.96 µM, SI = 16.00) showed significant selective activity against both viral models in comparison to ribavirin (IC₅₀ = 511.88 µM, SI > 8.00). Full article

Sialidases are gradually entering various areas of human practice—in medicine and pharmacy, as antiviral, antitumor, diagnostic, and vaccine preparations; for the chemoenzymatic synthesis of regioselective sialoglycoconjugates; and for the structural analysis of sialoglycoproteins. Optimizing the synthesis conditions of these commercially important enzymes would be beneficial for enhancing their production and expanding potential applications. Since sialidase producers are often pathogenic microorganisms, the use of saprophytic bacteria could be an alternative to reduce the health risk when working with them. So far, the topic has not been widely discussed. By a single-factor optimization method, the most suitable fermentation conditions for achieving maximum sialidase production by the non-model strain Oerskovia paurometabola O129 were established. The dynamics of enzyme accumulation during the growth phases and the optimal physicochemical parameters for cultivation were determined (30 °C, pH 8.0, agitation at 200 rpm, for 28 h). The addition of various inducers and surfactants to improve enzyme yield was also investigated. The effect of surfactants on bacterial sialidase production was tested for the first time. Maximum enzyme production (98.3 U/mL), representing about a three-fold increase compared to non-optimized conditions, was obtained by culturing the strain under optimal conditions and by the synergistic action of glucomacropeptide and Tween 80. A new, simple, and cost-effective laboratory model for optimizing sialidase production by the saprophytic strain O. paurometabola O129 in submerged fermentation was proposed. Future work may involve scaling up the process and exploring genetic or metabolic enhancements for targeted biomedical and industrial applications. Full article

Aberrant glycosylation, especially sialylation, on cell surface is often associated with cancer progression and immunosuppression. Over-sialylation of stage-specific embryonic antigen-4 (SSEA-4) to generate disialylGb5 (DSGb5) was reported to trigger Siglec-7 recognition and suppress NK-mediated target killing. In this study, efficient chemo-enzymatic and programmable one-pot methods were explored for the synthesis of DSGb5 and related sialosides for assembly of glycan microarrays and evaluation of binding specificity toward Siglecs-7, 9, 10, and 15 associated with immune checkpoint inhibition. The result showed weak binding of DSGb5 to these Siglecs; however, a truncated glycolyl glycan was identified to bind Siglec-10 strongly with a dissociation constant of 50 nM and exhibited a significant inhibition of Siglec-10 interacting with breast cancer cells. Full article

Heparosan, a microbially synthesized capsular polysaccharide, possesses a polysaccharide backbone structurally analogous to heparin. Its biosynthesis holds significant importance for achieving the chemoenzymatic synthesis of heparin. Here, we developed a systematic metabolic engineering strategy in Escherichia coli Nissle 1917 to establish an efficient heparosan production platform. Through the systematic engineering of the glycolytic pathway involving the targeted knockout of zwf, pfkAB, pgi, and fruA (or alternatively fbaA) genes, we generated recombinant strains that lost the capacity to utilize glucose or fructose as sole carbon sources in a minimal medium. This metabolic reprogramming established glycerol as the exclusive carbon source for cell growth, thereby creating a tripartite carbon allocation system, including glycerol for biomass, glucose for UDP-glucuronic acid, and fructose for UDP-N-acetylglucosamine. Therefore, heparosan production was significantly improved from 137.68 mg/L in the wild type to 414.40 mg/L in the recombinant strain. Building upon this foundation, the overexpression of glmM, pgm, and galU genes in the biosynthetic pathway enabled a heparosan titer of 773.78 mg/L in shake-flask cultures. Temporal induction optimization further enhanced titers to 1049.96 mg/L, representing a 7.60-fold enhancement compared to the wild-type strain. This study establishes a triple-carbon-source co-utilization strategy, which holds promising implications for the biosynthesis of heparosan-like microbial polysaccharides. Full article

Alcohol dehydrogenases (ADHs) are versatile enzymes that enable the reversible reduction of aldehydes and ketones to their corresponding alcohols. The exceptional chemo-, regio-, and stereoselectivity of ADHs position them as attractive catalysts for generating enantiopure alcohols, whether through deracemization of racemates or asymmetric reduction of prochiral ketones. The emergence of robust ADHs capable of functioning effectively at elevated temperatures and in high concentrations of non-aqueous media has stimulated interest in integrating ADH-catalyzed asymmetric transformations with other chemical processes in a single pot, either in a stepwise mode or simultaneously. This review presents an overview of one-pot organic transformations that combine ADH-catalyzed asymmetric reductions with additional nonenzymatic chemical reactions, demonstrating the potential for enhanced efficiency and sustainability in synthetic organic chemistry. Full article

The current paper reports the asymmetric synthesis of a focused library of enantiostructured triacylglycerols (TAGs) constituting a potent drug of the NSAID type (ibuprofen or naproxen) along with a pure bioactive n-3 polyunsaturated fatty acid (PUFA) intended as a novel type of prodrug. In this second category, a TAG prodrug of the terminal sn-1 or sn-3 position of the glycerol skeleton is acylated with a single saturated medium-chain fatty acid (C6, C8, C10, or C12), and another with the drug entity; the PUFA (EPA or DHA) is located in the sn-2 position. This was accomplished by a six-step chemoenzymatic approach, two of which were promoted by a lipase, starting from enantiopure (R)- and (S)-solketals. The highly regioselective immobilized Candida antarctica lipase (CAL-B) played a crucial role in the regiocontrol of the synthesis. The most challenging key step involved the incorporation of the drugs that were activated as oxime esters by the lipase exclusively in the terminal position of glycerol that is protected as a benzyl ether. All combinations, a total of 32 such prodrug TAGs, were prepared, isolated, and fully characterized, along with 24 acylglycerol intermediates, obtained in very-high-to-excellent yields in the majority of cases. Full article

Marine organisms represent a source of unique chemical entities with valuable biomedical potentialities, broad diversity, and complexity. It is essential to ensure a reliable and sustainable supply of marine natural products (MNPs) for their translation into commercial drugs and other valuable products. From a structural point of view and with few exceptions, MNPs of pharmaceutical importance derive from the so-called secondary metabolism of marine organisms. When production strategies rely on marine macroorganisms, harvesting or culturing coupled with extraction procedures frequently remain the only alternative to producing these compounds on an industrial scale. Their supply can often be implemented with laboratory scale cultures for bacterial, fungal, or microalgal sources. However, a diverse approach, combining traditional methods with modern synthetic biology and biosynthesis strategies, must be considered for invertebrate MNPs, as they are usually naturally accumulated in only very small quantities. This review offers a comprehensive examination of various production strategies for MNPs, addressing the challenges related to supply, synthesis, and scalability. It also underscores recent biotechnological advancements that are likely to transform the current industrial-scale manufacturing methods for pharmaceuticals derived from marine sources. Full article