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Isoiminosugars are highly biological active substances. Herein, we report a concise synthetic approach for this class of compounds. The key step relies on a stereospecific 1,2-hydride shift in O-2 tosylated glycopyranosides leading to C-2 branched glycofuranosides. This approach enables a 4-step synthesis of powerful β-galactosidase inhibitor 4-epi-isofagomine starting from a simple d-glucopyranoside., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Isopropyl 1-thio-β-D-galactopyranoside (IPTG, 1) is used widely as an inducer of protein expression in E. coli and 1-β-D-galactopyranosyl-2-methylpropane (2), a C -glycoside analogue of 1, has also been identified as an inducer. Here, synthesis and study of mimetics of 1 and 2, 1-β-D-galactopyranosyl-2-methylpropan-1-ols and two cyclic acetals derivatives, that constrain the presentation of the iPr group in various geometries is described. Conformational analysis of C -glycosides in protic solvent is performed using (i) Desmond metadynamics simulations (OPLS4) and (ii) use of 3 J HH values obtained by 1 H-NMR spectroscopy. 1-β-D-Galactopyranosyl-2-methylpropane (2) is an effective protein expression inducer when compared to the new mimetics, which were less effective or did not induce expression. 1-β-D-Galactopyranosyl-2-methylpropane (2) led to significantly reduced proteolysis during protein expression, compared to IPTG suggesting that recombinant protein purification will be easier to achieve with 2, yielding proteins with higher quality and activity. IPTG reduced bacterial growth to a greater degree than 2 compared to the control. IPTG's isopropyl group was observed by molecular dynamics (MD) simulations to be flexible in the binding pocket, deviating from its crystal structure binding mode, without impacting other interactions. The MD simulations predicted that 1-β-D-galactopyranosyl-2-methylpropane (2) was more likely than IPTG to bind the repressor with a conformation favoured in protic solvent, while maintaining interactions observed for IPTG. MD simulations predicted that isobutanol derivatives may disrupt interactions associated with IPTG's binding mode. The compounds were also evaluated as inhibitors of galactosidases, with 2 being the more potent inhibitor of the E. coli β-galactosidase. The constrained cyclic acetals showed similar inhibition constants to IPTG indicating E. coli β-galactosidase can recognize galactopyranoses with varying presentation of the iPr group.

Broussonetine S (9), its C-1' and C-10' stereoisomers, and their corresponding enantiomers have been synthesized from enantiomeric arabinose-derived cyclic nitrones, with cross metathesis (CM), epoxidation and Keck asymmetric allylation as key steps. Glycosidase inhibition assays showed that broussonetine S (9) and its C-10' epimer (10'-epi-9) were nanomolar inhibitors of bovine liver β-galactosidase and β-glucosidase; while their C-1' stereoisomers were 10-fold less potent towards these enzymes. The glycosidase inhibition results and molecular docking calculations revealed the importance of the configurations of pyrrolidine core and C-1' hydroxyl for inhibition potency and spectra. Together with the docking calculations we previously reported for α-1-C-alkyl-DAB derivatives, we designed and synthesized a series of 6-C-alkyl-DMDP derivatives with very simple alkyl chains. The inhibition potency of these derivatives was enhanced by increasing the length of the side chain, and maintained at nanomolar scale inhibitions of bovine liver β-glucosidase and β-galactosidase after the alkyl groups are longer than eight or ten carbons for the (6R)-C-alkyl-DMDP derivatives and their 6S epimers, respectively. Molecular docking calculations indicated that each series of 6-C-alkyl-DMDP derivatives resides in the same active site of β-glucosidase or β-galactosidase with basically similar binding conformations, and their C-6 long alkyl chains extend outwards along the hydrophobic groove with similar orientations. The increasing inhibitions of β-glucosidase and β-galactosidase with the number of carbon atoms in the side chains may be explained by improved adaptability of longer alkyl chains in the hydrophobic grooves. In addition, the lower β-glucosidase and β-galactosidase inhibitions of (6S)-C-alkyl-DMDP derivatives than their C-6 R stereoisomers can be attributed to the misfolding of their alkyl chains and resulted decreased adaptability in the hydrophobic groove. The work reported herein is valuable for design and development of more potent and selective inhibitors of β-galactosidase and β-glucosidase, which have potential in treatment of lysosomal storage diseases. Furthermore, part of the 6-C-alkyl-DMDP derivatives and their enantiomers were also tested as potential anti-cancer agents; all the compounds tested were found with moderate cytotoxic effects on MKN45 cells, which would indicate potential applications of these iminosugars in development of novel anticancer agents., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

A short survey on selected β-galactosidase inhibitors as potential pharmacological chaperones for G M1 -gangliosidosis and Morquio B associated mutants of human lysosomal β-galactosidase is provided highlighting recent developments in this particular area of lysosomal storage disorders and orphan diseases., (© 2021 The Authors. Published by The Chemical Society of Japan & Wiley-VCH GmbH.)

In traditional medicine, various parts of the plant Juglans regia L. are used to treat several pathological conditions including diabetes and infectious and periodontal diseases. This includes the bark of Juglans regia . The present study is aimed at evaluating for the first time the mineral composition, investigating the antidiabetic and antibacterial properties of Moroccan J. regia bark, and finally determining the correlations between the chemical composition of the tested extracts and their biological activities. The mineral composition was determined using inductively coupled plasma atomic emission spectroscopy. Then, nine extracts were prepared by different methods and modalities of extractions and investigated for their antidiabetic activities, via tests of inhibition of alpha-amylase, alpha-glucosidase, and beta-galactosidase enzymes, and for their antibacterial activities against six strains involved in infectious diseases and periodontology. Finally, the correlation between the chemical compositions of the different extracts prepared and their antidiabetic and antibacterial potencies was determined by Principal Component Analysis (PCA). J. regia is an important source of mineral elements, mainly Fe (19849.8), K (3487.8), Mg (2631.03), and P (691.02) mg/kg plant material. All the extracts of J. regia possess antidiabetic activity, and in particular, the macerated acetone extract gave the highest inhibitory activity against alpha-amylase (IC 50 value of 5445.33 ± 82.58  μ g/mL), alpha-glucosidase (IC 50 value of 323.7 ± 1.71  μ g/mL), and beta-galactosidase (IC 50 value of 811.2 ± 8.32  μ g/mL). For the results of antibacterial activity, the macerated acetone extract at the concentration of 80 mg/mL was found to be the most active by inducing inhibition diameters of 12, 17, 18, 11, 14.5, and 16 mm against Escherichia coli , Proteus mirabilis , Pseudomonas aeruginosa , Staphylococcus aureus , Bacillus subtilis , and Listeria innocua , respectively. PCA allowed us to deduce that the extracts richer in polyphenols, in particular, the two acetone and ethanol macerates, have a better antidiabetic activity against alpha-glucosidase as well as a better antibacterial activity. The results of the present study revealed that the aqueous and organic macerate extracts showed a better antidiabetic activity and justified the use of J. regia bark as an antibacterial and antiseptic agent in traditional Moroccan medicine in the treatment of dental affections., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Mohamed Boulfia et al.)

Quinone methide (QM) species have been included in the design of various functional molecules. In this review, we present a comprehensive overview of bioanalytical tools based on QM chemistry. In the first part, we focus on self-immolative linkers that have been incorporated into functional molecules such as prodrugs and fluorescent probes. In the latter half, we outline how the highly electrophilic property of QMs, enabling them to react rapidly with neighboring nucleophiles, has been applied to develop inhibitors or labeling probes for enzymes, as well as self-immobilizing fluorogenic probes with high spatial resolution. This review systematically summarizes the versatile QM toolbox available for investigating biological processes., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Enzyme inhibitors play a crucial role in diagnosis of a wide spectrum of diseases related to bacterial infections. We report here the effect of a water-soluble self-assembled Pd II 8 molecular cage towards β-galactosidase enzyme activity. The molecular cage is composed of a tetrapyridyl donor (L) and cis-[(en)Pd(NO 3 ) 2 ] (en=ethane-1,2-diamine) acceptor and it has a hydrophobic internal cavity. We have observed that the acceptor moiety mainly possesses the ability to inactivate the β-galactosidase enzyme activity. Kinetic investigation revealed the mixed mode of inhibition. This inhibition strategy was extended to control the growth of methicillin-resistant Staphylococcus aureus. The internalization of the Pd(II) cage inside the bacteria was confirmed when bacterial solutions were incubated with curcumin loaded cage. The intrinsic green fluorescence of curcumin made the bacteria glow when put under an optical microscope. Furthermore, this curcumin loaded molecular cage shows an enhanced antibacterial activity. Thus, Pd II 8 molecular cage is quite attractive due to its dual role as enzyme inhibitor and drug carrier., (© 2021 Wiley-VCH GmbH.)

Pharmacological chaperones (PCs) are small compounds able to rescue the activity of mutated lysosomal enzymes when used at subinhibitory concentrations. Nitrogen-containing glycomimetics such as aza- or iminosugars are known to behave as PCs for lysosomal storage disorders (LSDs). As part of our research into lysosomal sphingolipidoses inhibitors and looking in particular for new β-galactosidase inhibitors, we report the synthesis of a series of alkylated azasugars with a relative " all-cis " configuration at the hydroxy/amine-substituted stereocenters. The novel compounds were synthesized from a common carbohydrate-derived piperidinone intermediate 8 , through reductive amination or alkylation of the derived alcohol. In addition, the reaction of ketone 8 with several lithium acetylides allowed the stereoselective synthesis of new azasugars alkylated at C-3. The activity of the new compounds towards lysosomal β-galactosidase was negligible, showing that the presence of an alkyl chain in this position is detrimental to inhibitory activity. Interestingly, 9 , 10 , and 12 behave as good inhibitors of lysosomal β-glucosidase (GCase) (IC 50 = 12, 6.4, and 60 µM, respectively). When tested on cell lines bearing the Gaucher mutation, they did not impart any enzyme rescue. However, altogether, the data included in this work give interesting hints for the design of novel inhibitors.

Cell senescence is due to the permanent cell cycle arrest that occurs as a result of the inherent limited replicative capacity toward the Hayflick limit (replicative senescence), or in response to various stressors (stress-induced premature senescence, SIPS). With the acquisition of the senescence-associated secretory phenotype (SASP), cells release several molecules (cytokines, proteases, lipids), and express the senescence-associated beta-galactosidase (SA-β-Gal). Here we tested whether vitamin E affects SA-β-Gal in an in vitro model of cell ageing. Skin fibroblasts from human subjects of different age (1, 13, 29, 59, and 88 years old) were cultured until they reached replicative senescence. At different passages (Passages 2, 9, 13, and 16), these cells were treated with vitamin E for 24 hr. Vitamin E reduced SA-β-Gal in all cells at passage 16, but at earlier passage numbers it reduced SA-β-Gal only in cells isolated from the oldest subjects. Therefore, short time treatment with vitamin E decreases SA-β-Gal in cells both from young and old subjects when reaching replicative senescence; but in cells isolated from older subjects, a decrease in SA-β-Gal by vitamin E occurs also at earlier passage numbers. The possible role of downregulation of CD36 by vitamin E, a scavenger receptor essential for initiation of senescence and SASP, is discussed., (© 2020 International Union of Biochemistry and Molecular Biology.)

The genes GLB1 and GALC encode GLB1 isoform 1 and galactocerebrosidase, respectively, which exhibit β-galactosidase activity in human lysosomes. GLB1 isoform 1 has been reported to play roles in rare lysosomal storage diseases. Further, its β-galactosidase activity is the most widely used biomarker of senescent and aging cells; hence, it is called senescence-associated β-galactosidase. Galactocerebrosidase plays roles in Krabbe disease. We previously reported a novel β-galactosidase activity in the Golgi apparatus of human cells; however, the protein responsible for this activity could not be identified. Inhibitor-derived chemical probes can serve as powerful tools to identify the responsible protein. In this study, we first constructed a cell-based high-throughput screening (HTS) system for Golgi β-galactosidase inhibitors, and then screened inhibitors from two compound libraries using the HTS system, in vitro assay, and cytotoxicity assay. An isoflavone derivative was identified among the final Golgi β-galactosidase inhibitor compound hits. Molecular docking simulations were performed to redesign the isoflavone derivative into a more potent inhibitor, and six designed derivatives were then synthesized. One of the derivatives, ARM07, exhibited potent inhibitory activity against β-galactosidase, with an IC 50 value of 14.8 µM and competitive inhibition with K i value of 13.3 µM. Furthermore, the in vitro and cellular inhibitory activities of ARM07 exceeded those of deoxygalactonojirimycin. ARM07 may contribute to the development of affinity-based chemical probes to identify the protein responsible for the newly discovered Golgi β-galactosidase activity. The therapeutic relevance of ARM07 against lysosomal storage diseases and its effect on senescent cells should be evaluated further.

In this study, an attempt has been made to evaluate the effect of products of β-galactosidase (βGS) catalyzed reaction i.e. glucose and galactose and their structurally related compound vitamin C (VC) on the catalytic activity of native and PANI-CS-NC and PANI-CS-Ag-NC adsorbed βGS. Results indicated a decline in catalytic activity of soluble enzyme in the presence of all investigated compounds. The order of inhibition was found to be VC < glucose < galactose. However, the immobilized preparations were found more resistant to inactivation caused by the added compounds. About 48% activity was retained by PANI-CS-Ag-NC-βGS in the presence of galactose (5%, w/v), while the native enzyme exhibited only 18% of its original activity. A significant decrease in absorbance and fluorescence intensity was evaluated in soluble enzyme incubated in the presence of all investigated compounds. Three-dimensional fluorescence graphs, CD and FT-IR spectroscopic studies illustrated noteworthy conformational changes in the secondary structure and microenvironment of the soluble enzyme in the presence of VC and tested sugars. These results suggest that both PANI-CS-NC and PANI-CS-Ag-NC bound βGS are more resistant to the exposure caused by the higher concentration of added glucose, galactose, and VC and, therefore, can be effectively utilized for the production of a hassle-free lactose nano-biosensor.

Activated endocytosis of extracellular macromolecules and their intracellular trafficking to lysosomes is an essential metabolic mechanism in cancer cells during their rapid proliferation. Cancer cells reuse a vast amount of N-acetylglucosamine (GlcNAc) supplied from the GlcNAc salvage pathway for the accelerated synthesis of a pivotal uridine diphosphate (UDP)-GlcNAc. A method to inactivate key glycosidases in lysosomes could critically contribute to the development of potent anticancer therapy. Here we demonstrate that "nanosomes" made of core metals covered by an antiadhesive mixed self-assembled monolayer allow for avoiding nonspecific surface protein corona and targeted molecular delivery through activated endocytosis. Nanosomes carrying suicide substrates showed that lysosomal glycosidases such as β-hexosaminidase and β-galactosidase in cancer cells are promising targets for novel anticancer therapeutic nanomedicine that induce apoptotic cell death through lysosomal membrane permeabilization. The advantage of this method is evident because multivalent surface loading by antiadhesive nanosomes makes it possible to highlight "weak interactions" such as carbohydrate-lectin interactions independent of surface protein corona., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A fully mechanized Arduino-controlled multi-pumping flow analysis system and procedure for the determination of β-galactosidase activity are proposed. The applied bioanalytical method is based on the determination of p-nitrophenol formed in the course of enzyme-catalyzed hydrolysis of p-nitrophenyl-galactopyranosides. The photometric detection is performed using dedicated flow-through optoelectronic detector made of paired light emitting diodes. The developed bioanalytical system was applied for evaluation of optimal enzyme detection conditions (pH, temperature and reaction time), selection of appropriate substrate for the assays, comparison of enzymes of different origins (isoenzymes), detection of β-galactosidase inhibitor and finally to the determination of enzyme activity in some dietary supplements dedicated for people suffering from lactose intolerance. Depending on measurements conditions the developed bioanalytical system allows determination of β-galactosidase in the wide range of activity (up to 15 U/mL at detection limit ca 0.01 U/mL) with high sample flowthroughput (up to 30 detections per hour). Additionally, the potential utility of the developed analytical system for amyloglucosidase activity assays has been demonstrated., (Copyright © 2019. Published by Elsevier Ltd.)

Fine dust (FD) is a form of air pollution and is responsible for a wide range of diseases. Specially, FD is associated with several cardiovascular diseases (CVDs); long-term exposure to FD was shown to decrease endothelial function, but the underlying mechanism remains unclear. We investigated whether exposure to FD causes premature senescence-associated endothelial dysfunction in endothelial cells (ECs) isolated from porcine coronary arteries. The cells were treated with different concentrations of FD and senescence associated-beta galactosidase (SA-β-gal) activity, cell cycle progression, expression of endothelial nitric oxide synthase (eNOS), oxidative stress level, and vascular function were evaluated. We found that FD increased SA-β-gal activity, caused cell cycle arrest, and increased oxidative stress, suggesting the premature induction of senescence; on the other hand, eNOS expression was downregulated and platelet aggregation was enhanced. FD exposure impaired vasorelaxation in response to bradykinin and activated the local angiotensin system (LAS), which was inhibited by treatment with the antioxidant N-acetyl cysteine (NAC) and angiotensin II receptor type 1 (AT 1 ) antagonist losartan (LOS). NAC and LOS also suppressed FD-induced SA-β-gal activity, increased EC proliferation and eNOS expression, and improved endothelial function. These results demonstrate that FD induces premature senescence of ECs and is associated with increased oxidative stress and activation of LAS. This study can serve as a pharmacological target for prevention and/or treatment of air pollution-associated CVD., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A novel antimicrobial peptide named NP-6 was identified in our previous work. Here, the mechanisms of the peptide against Escherichia coli (E. coli) were further investigated, as well as the peptide's resistance to temperature, pH, salinity, and enzymes. The transmission electron microscopy (TEM), confocal laser scanning microcopy (CLSM), and flow cytometric (FCM) analysis, combined with measurement of released K + , were performed to evaluate the effect of NP-6 E. coli cell membrane. The influence of NP-6 on bacterial DNA/RNA and enzyme was also investigated. The leakage of K + demonstrated that NP-6 could increase the permeability of E. coli cell membrane. The ATP leakage, FCM, and CLSM assays suggested that NP-6 caused the disintegration of bacterial cell membrane. The TEM observation indicated that NP-6 could cause the formation of empty cells and debris. Besides, the DNA-binding assay indicated that NP-6 could bind with bacterial genomic DNA in a way that ethidium bromide (EB) did, and suppress the migration of DNA/RNA in gel retardation. Additionally, NP-6 could also affect the activity of β-galactosidase. Finally, the effect of different surroundings such as heating, pH, ions, and protease on the antimicrobial activity of NP-6 against E. coli was also investigated. Results showed that the peptide was heat stable in the range of 60~100 °C and performed well at pH 6.0~8.0. However, the antimicrobial activity of NP-6 decreased significantly in the presence of Mg 2+ /Ca 2+ , and after incubation with trypsin/proteinase K. The results will provide a theoretical support in the further application of NP-6.

DMDP acetic acid [N-carboxymethyl-2,5-dideoxy-2,5-imino-D-mannitol] 5 from Stevia rebaudiana is the first isolated natural amino acid derived from iminosugars bearing an N-alkyl acid side chain; it is clear from GCMS studies that such derivatives with acetic and propionic acids are common in a broad range of plants including mulberry, Baphia, and English bluebells, but that they are very difficult to purify. Reaction of unprotected pyrrolidine iminosugars with aqueous glyoxal gives the corresponding N-acetic acids in very high yield; Michael addition of both pyrrolidine and piperidine iminosugars and that of polyhydroxylated prolines to tert-butyl acrylate give the corresponding N-propionic acids in which the amino group of β-alanine is incorporated into the heterocyclic ring. These easy syntheses allow the identification of this new class of amino acid in plant extracts and provide pure samples for biological evaluation. DMDP N-acetic and propionic acids are potent α-galactosidase inhibitors in contrast to potent β-galactosidase inhibition by DMDP.

Degradation products of elastin, i.e. elastin-derived peptides (EDPs), are involved in various physiological and pathological processes. EDPs are detectable in cerebrospinal fluid in healthy people and in patients after ischemic stroke. However, to date, no studies concerning the role of EDP in the nervous system were conducted. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) play important roles during the repair phases of cerebral ischemia, particularly during angiogenesis and reestablishment of cerebral blood flow. Therefore, the aim of this study was to investigate the impact of the specific elastin-derived peptide VGVAPG on Mmp-2, -9 and Timp-1, -2, -3 and -4 mRNA expression in mouse cortical glial cells in vitro. Primary glial cells were maintained in DMEM/F12 without phenol red supplemented with 10% fetal bovine serum and the cells were exposed to 50 nM, 1 and 50 μM of the VGVAPG peptide. After 3 and 6 h of exposition to the peptide, expression of Mmp-2, -9 and Timp-1, -2, -3 and -4 mRNA was measured. Moreover, siRNA gene knockdown, cytotoxicity and apoptosis measurement were included in our experiments, which showed that VGVAPG in a wide range of concentrations exhibited neither proapoptotic nor cytotoxic properties in mouse glial cells in vitro. The peptides enhanced mRNA expression of Timp-2 and Timp-3 genes in an elastin-binding protein (EBP)-dependent manner. However, changes in mRNA expression of Mmp-2, Mmp-9 and Timp-4 were partially EBP-dependent. The decrease in mRNA expression of Timp-1 was EBP-independent. However, further studies underlying the VGVAPG peptide's mechanism of action in the nervous system are necessary.

It has been a challenge to develop in vitro alternative test methods for accurate prediction of metallic products which may exert skin sensitization, as several test methods adopted by OECD were relatively ineffective in assessing the capacity for metallic compounds to exert sensitizing reactions, compared with organic test substances. Based upon these findings, a system that incorporates β-galactosidase producing E. coli cultures was tested for its predictive capacity to well-known metallic sensitizers. In this system, E. coli cells were incubated with metal salts at various concentrations and β-galactosidase suppression by each test metal was determined. Fourteen local lymph node assay (LLNA) categorized metal salts were examined. Although color interference from metal salts was minimal, a fluorometric detection system was also employed using 4-methylumbelliferyl galactopyranoside as a substrate for β-galactosidase to avoid the color interference, concomitantly with the original UV-spectrometric method. Data demonstrated that two detection methods were comparable and complementary. In addition, most of the metallic sensitizers were correctly identified at 0.6 and 0.8 mM concentrations. Despite the lower specificity obtained in the current study and small number of substances tested, the developed method appears to be a relatively simple and effective in vitro method for detecting metallic sensitizers. When 61 chemicals tested in the β-galactosidase producing E. coli cultures including the present study were collectively analyzed, the prediction capacity was as high as other OECD-adopted tests: 95.6% of sensitivity, 66.7% of specificity, and 88.5% of accuracy. It is important to emphasize that animals or mammalian cell cultures were not required in the current method, which are in accordance with the EU guidelines on restricted or banned animal testing.

(5aR)-5a-C-pentyl-4-epi-isofagomine 1 is a powerful inhibitor of lysosomal β-galactosidase and a remarkable chaperone for mutations associated with GM1-gangliosidosis and Morquio disease type B. We report herein an improved synthesis of this compound and analogs (5a-C-methyl, pentyl, nonyl and phenylethyl derivatives), and a crystal structure of a synthetic intermediate that confirms its configuration resulting from the addition of a Grignard reagent. These compounds were evaluated as glycosidase inhibitors and their potential as chaperones for mutant lysosomal galactosidases determined. Based on these results and on docking studies, the 5-C-pentyl derivative 1 was selected as the optimal structure for further investigations: this compound induces the maturation of mutated β-galactosidase in fibroblasts of a GM1-gangliosidosis patient and promote the decrease of keratan sulfate and oligosaccharide load in patient cells. Compound 1 is clearly capable of restoring β-galactosidase activity and of promoting maturation of the protein, which should result in significant clinical benefit. These properties strongly support the development of compound 1 for the treatment of GM1-gangliosidosis and Morquio disease type B patients harboring β-galactosidase mutations sensitive to pharmacological chaperoning., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Azobenzenes are of particular interest as a photochromic scaffold for biological applications because of their high fatigue resistance, their large geometrical change between extended (trans) and bent (cis) isomer, and their diverse synthetic accessibility. Despite their wide-spread use, there is no reported photochromic inhibitor of the well-investigated enzyme β-galactosidase, which plays an important role for biochemistry and single molecule studies. Herein, we report the synthesis of photochromic competitive β-galactosidase inhibitors based on the molecular structure of 2-phenylethyl β-d-thiogalactoside (PETG) and 1-amino-1-deoxy-β-d-galactose (β-d-galactosylamine). The thermally highly stable PETG-based azobenzenes show excellent photochromic properties in polar solvents and moderate to high photostationary states (PSS). The optimized compound 37 is a strong competitive inhibitior of β-galactosidase from Escherichia coli and its inhibition constant (Ki) changes between 60 nM and 290 nM upon irradiation with light. Additional docking experiments supported the observed structure-activity relationship.

The key step in a new synthesis of 2-acetamido-2,3-dideoxy-(1→4)-thiodisaccharides was the conjugate addition of a 1-thiogalactose derivative to E and Z acetyl oximes derived from sugar enones. This reaction was shown to be completely diastereoselective for both the formation of the thioglycosidic linkage and the configuration of acetyl oxime. The thiodisaccharides have been designed as inhibitors of the β-galactosidase from E. coli, and they have been shown to successfully meet such requirements.

Amphiphilic urea 1 with a hydrophilic lactose group was prepared as a low-molecular-weight hydrogelator, which formed a transparent supramolecular hydrogel. Enzymatic hydrolysis of the lactose moiety using β-galactosidase allowed a gel-to-sol phase transition of the supramolecular hydrogel. A β-galactosidase inhibitor enables us to control the time course of this phase transition.

Ultraviolet B (UVB) radiation induces the production of reactive oxygen species (ROS), resulting in the aging of dermal fibroblasts. Crocin, a bioactive constituent of Crocus sativus, possesses anti‑oxidation effects. The purpose of the present study was to evaluate the protective effect of crocin on UVB‑induced dermal fibroblast photoaging. Human dermal fibroblasts were isolated and cultured with different concentrations of crocin prior to and following exposure to UVB irradiation. The senescent phenotypes of cells were evaluated, including cell proliferation, cell cycle, senescence‑associated β‑galactosidase (SA‑β‑gal) expression, intracellular ROS, expression of antioxidant protein glutathione peroxidase 1 (GPX‑1) and extracellular matrix protein collagen type 1 (Col‑1). Crocin rescued the cell proliferation inhibited by UVB irradiation, prevented cell cycle arrest and markedly decreased the number of SA‑β‑gal‑positive cells. In addition, crocin reduced UVB‑induced ROS by increasing GPX‑1 expression and other direct neutralization effects. Furthermore, crocin promoted the expression of the extracellular matrix protein Col‑1. Crocin could effectively prevent UVB‑induced cell damage via the reduction of intracellular ROS; thus, it could potentially be used in the prevention of skin photoaging.

The synthesis of three libraries (1a-l, 1a'-l' and 2a-l) of dimeric iminosugars through CuAAC reaction between three different alkynyl pyrrolidines and a set of diazides was carried out. The resulting crude dimers were screened in situ against two α-fucosidases (libraries 1a-l and 1a'-l') and one β-galactosidase (2a-l). This method is pioneer in the search of divalent glycosidase inhibitors. It has allowed the rapid identification of dimer 1i as the best inhibitor of α-fucosidases from bovine kidney (K i  = 0.15 nM) and Homo sapiens (K i  = 60 nM), and dimer 2e as the best inhibitor of β-galactosidase from bovine liver (K i  = 5.8 μM). In order to evaluate a possible divalent effect in the inhibition, the synthesis and biological analysis of the reference monomers were also performed. Divalent effect was only detected in the inhibition of bovine liver β-galactosidase by dimer 2e., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

The present study aimed to work out a high yield procedure for immobilization of Aspergillus oryzae β-galactosidase on polyaniline cobalt multiwalled carbon nanotubes nanocomposite (PANI/Co/MWCNTNC) by physical adsorption and covalent attachment via glutaraldehyde. The binding was confirmed by scanning and transmission electron microscopy along with Fourier transform-infrared spectroscopy. The immobilization yields obtained for adsorbed and cross-linked enzymes were 93% and 97%, respectively. The covalently immobilized enzyme was remarkably more stable at extremes of pH and temperature compared to native and adsorbed enzymes. The K i values were found to increase ten-folds for covalently immobilized β-galactosidase indicating that this immobilized enzyme was markedly more resistant to galactose inhibition. The covalently attached enzyme retained 92% activity after its 10th successive reuse compared to the adsorbed β-galactosidase which exhibited 74% of its initial activity. Furthermore, no significant change was noticed in the band intensity of pBR 322 plasmid when exposed to free and bound nanocomposite. The covalently bound enzyme exhibited superiority in terms of stability and reusability when compared to the adsorbed and native β-galactosidase. The results, presented here demonstrate an efficient method of immobilization of β-galactosidase on PANI/Co/MWCNTNC in order to construct a convenient and novel biosensor for the detection of lactose concentration., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In an effort to examine similarities in the active sites of glycosidases within the GH35 family, we performed a structure-activity-relationship study using our recently described library of galactonoamidines. The kinetic evaluation based on UV/Vis spectroscopy disclosed inhibition of β-galactosidase (bovine liver) in the picomolar concentration range indicating significantly higher inhibitor affinity than previously determined for β-galactosidase (A. oryzae). Possible alterations in the secondary protein structure or folding were excluded after further examination of the inhibitor binding using CD spectroscopy. Molecular dynamics studies suggested loop closing interactions as a rationale for the disparity of the active sites in the β-galactosidases under investigation., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

A simple strategy for the synthesis of α-geminal disubstituted pyrrolidine iminosugars 3a-c and their C-4 fluorinated derivatives 4a-c has been described from d-glucose. The methodology involves the Corey-Link and Jocic-Reeve reaction with 3-oxo-α-d-glucofuranose and nucleophilic displacement reaction to get the furanose fused pyrrolidine ring skeleton with requisite CH 2 OH/CO 2 H functionalities at C-3. The fluorine substituent in target molecules was introduced by nucleophilic displacement of -OTf in 9a/9c with CsF. Appropriate manipulation of the anomeric carbon in the furanose fused pyrrolidine ring skeleton afforded α-geminal disubstituted pyrrolidine iminosugars 3a-c and C-4 fluoro derivatives 4a-c. The pyrrolidine iminosugars 3a and 3c were found to be potent inhibitors of α-galactosidase while, the fluoro derivatives 4a and 4b showed strong inhibition of β-glucosidase and β-galactosidase, respectively. These results were substantiated by in silico molecular docking studies., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Endoplasmic reticulum stress (ERS) has been shown to participate in many disease pathologies. Recent reports have reported that ERS exists in human osteoarthritis (OA) chondrocytes. During OA, chondrocytes exhibit increased level of some senescence marker, such as senescence-associated β-galactosidase (SA β-gal) activity. However, the persistence and accumulation of senescent cells in various tissues can also impair function and have been involved in the pathogenesis of many age-related diseases, including OA. In this present study, we used IL-1β (10 ng/ml) to mimic OA chondrocytes and we found that IL-1β stimulated chondrocytes caused the increasing expression of ADAMTS5 and MMP13, decreasing COL2A1 expression, which were in accord with OA chondrocytes changes. Our data also showed that ERS is involved in the OA chondrocytes, SA β-gal activity significantly increases and inhibition of ERS can decrease the SA β-gal activity, apoptosis of OA chondrocytes and increase cell viability. These results help us to open new perspectives for the development of molecular-targeted treatment approaches and thus present an effective novel therapeutic approach for OA., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The metabolism of living systems involves many enzymes that play key roles as catalysts and are essential to biological function. Searching ligands with the ability to modulate enzyme activities is central to diagnosis and therapeutics. Peptides represent a promising class of potential enzyme modulators due to the large chemical diversity, and well-established methods for library synthesis. Peptides and their derivatives are found to play critical roles in modulating enzymes and mediating cellular uptakes, which are increasingly valuable in therapeutics. We present a methodology that uses molecular dynamics (MD) and point-variant screening to identify short peptide motifs that are critical for inhibiting β-galactosidase (β-Gal). MD was used to simulate the conformations of peptides and to suggest short motifs that were most populated in simulated conformations. The function of the simulated motifs was further validated by the experimental point-variant screening as critical segments for inhibiting the enzyme. Based on the validated motifs, we eventually identified a 7-mer short peptide for inhibiting an enzyme with low μM IC50. The advantage of our methodology is the relatively simplified simulation that is informative enough to identify the critical sequence of a peptide inhibitor, with a precision comparable to truncation and alanine scanning experiments. Our combined experimental and computational approach does not rely on a detailed understanding of mechanistic and structural details. The MD simulation suggests the populated motifs that are consistent with the results of the experimental alanine and truncation scanning. This approach appears to be applicable to both natural and artificial peptides. With more discovered short motifs in the future, they could be exploited for modulating biocatalysis, and developing new medicine.

N-Functionalized amino(hydroxymethyl)cyclopentanetriols are potent inhibitors of β-d-galactosidases and, for the first time, could be shown to act as pharmacological chaperones for G M1 -gangliosidosis-associated lysosomal acid β-galactosidase thus representing a new structural type of pharmacological chaperones for this lysosomal storage disease., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

From 1,2;3,4-di-O-isopropylidene-α-D-galactopyranose, a series of highly functionalized (hydroxymethyl)cyclopentanes was easily available. In line with reports by Reymond and Jäger on similar structures, these amine containing basic carbasugars are potent inhibitors of β-D-galactosidases and, for the first time, could be shown to act as pharmacological chaperones for G M1 -gangliosidosis-associated lysosomal acid β-galactosidase mutant R201C, thus representing a new structural type of pharmacological chaperones for this lysosomal storage disease., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

A series of lipidated guanidino and urea derivatives of 1,5-dideoxy-1,5-imino-d-xylitol were prepared from d-xylose using a concise synthetic protocol. Inhibition assays with a panel of glycosidases revealed that the guanidino analogues display potent inhibition against human recombinant β-glucocerebrosidase with IC 50 values in the low nanomolar range. Related urea analogues of 1,5-dideoxy-1,5-imino-d-xylitol were also synthesized and evaluated in the same fashion and found to be selective for β-galactosidase from bovine liver. No inhibition of human recombinant β-glucocerebrosidase was observed for the urea analogues. Computational studies provided insight into the potent activity of analogues bearing the substituted guanidine moiety in the inhibition of lysosomal glucocerebrosidase (GBA)., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A series of N-alkyl derivatives of the D-galactosidase inhibitor 1,4-di-epi-validamine featuring lipophilic substituents at position C-5a was prepared and screened for their glycosidase inhibitory properties. Products turned out selective for β-galactosidases as well as β-glucosidases., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

This report is about the identification, synthesis and initial biological characterization of derivatives of 4-epi-isofagomine as pharmacological chaperones (PC) for human lysosomal β-galactosidase. The two epimers of 4-epi-isofagomine carrying a pentyl group at C-5a, namely (5aR)- and (5aS)-5a-C-pentyl-4-epi-isofagomine, were prepared by an innovative procedure involving in the key step the addition of nitrohexane to a keto-pentopyranoside. Both epimers were evaluated as inhibitors of the human β-galactosidase: the (5aR)-stereoisomer (compound 1) was found to be a very potent inhibitor of the enzyme (IC 50  = 8 nM, 30× more potent than 4-epi-isofagomine at pH 7.3) with a high selectivity for this glycosidase whereas the (5aS) epimer was a much weaker inhibitor. In addition, compound 1 showed a remarkable activity as a PC. It significantly enhanced the residual activity of mutant β-galactosidase in 15 patient cell lines out of 23, with enhancement factors greater than 3.5 in 10 cell lines and activity restoration up to 91% of normal. Altogether, these results indicated that (5aR)-5a-C-pentyl-4-epi-isofagomine constitutes a promising PC-based drug candidate for the treatment of GM1-gangliosidosis and Morquio disease type B., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

A β-d-galactosidase exhibiting high activity in the alkaline pH region was purified from Teratosphaeria acidotherma AIU BGA-1, which we previously isolated as a unique fungal producer of three acidophilic and one alkalophilic β-d-galactosidases (Isobe et al., J. Biosci. Bioeng., 116, 171-174, 2013). The enzyme was stable in the pH range 7.5-10.0 and exhibited optimal activity at pH 8.0 and 60°C. The enzyme hydrolyzed 2-nitrophenyl β-d-galactopyranoside, 4-nitrophenyl β-d-galactopyranoside, and lactose, and the K m values were estimated to be 0.349 mM, 0.488 mM, and 701 mM, respectively. Chelating reagents (EDTA and o-phenanthroline) and metals (Cu 2+ and Ni 2+ ) inhibited the enzyme activity, and Mn 2+ was a good activator. The enzyme also exhibited transgalactosylation activity for lactose. The enzyme's molecular mass was estimated to be 180 kDa, and its structure was monomeric. Thus, the enzymatic and physicochemical characteristics of the alkalophilic β-galactosidase in this study clearly differed from those of the previously known alkalophilic β-d-galactosidases., (Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

Activity-based protein profiling (ABPP) has emerged as a powerful proteomic approach to study the active proteins in their native environment by using chemical probes that label active site residues in proteins. Traditionally, ABPP is classified as either comparative or competitive ABPP. In this protocol, we describe a simple method called convolution ABPP, which takes benefit from both the competitive and comparative ABPP. Convolution ABPP allows one to detect if a reduced signal observed during comparative ABPP could be due to the presence of inhibitors. In convolution ABPP, the proteomes are analyzed by comparing labeling intensities in two mixed proteomes that were labeled either before or after mixing. A reduction of labeling in the mix-and-label sample when compared to the label-and-mix sample indicates the presence of an inhibitor excess in one of the proteomes. This method is broadly applicable to detect inhibitors in proteomes against any proteome containing protein activities of interest. As a proof of concept, we applied convolution ABPP to analyze secreted proteomes from Pseudomonas syringae-infected Nicotiana benthamiana leaves to display the presence of a beta-galactosidase inhibitor.

Background: Some antibacterial agents exert their antimicrobial action by targeting the cytoplasmic macromolecules, such as proteins or nucleic acids, to disturb the properties of macromolecules that may deeply influence their biological activities and functions. Cinnamaldehyde (CIN) is a natural antibacterial ingredient found in the bark and leaves of cinnamon trees., Methods: The inhibitory mechanism of a typical enzyme, β-galactosidase by CIN was investigated by UV-visible, fluorescence, 3-D spectroscopy, circular dichroism, atomic force microscopy and molecular modeling studies., Results: CIN decreased the activity of β-galactosidase by competitive inhibition through a multiphase kinetic process. 3-D spectroscopy and circular dichroism showed that the binding of CIN to β-galactosidase resulted in changes in micro-environment of tryptophan and tyrosine residues, and conformation of β-galactosidase. The molecular recognition was also analyzed through modeling which indicated that CIN was inserted into the active site pocket of β-galactosidase and interacted with amino acid residues, such as Met502, Trp568, Phe601 and Trp999. Atomic force microscopy showed that a serious destabilization of the native conformation of β-galactosidase occurred after binding with CIN, e.g., morphological changes and increased dimensions of the β-galactosidase molecule. Moreover, it was found that the combinations of CIN, carvacrol and thymol exposure displayed synergistic effects on the inhibition of β-galactosidase., General Significance: This study exhibits a comprehensively understanding about the action mechanism of CIN that affects the conformation and activity of β-galactosidase in biochemical processes and provides some new insights into the possible intracellular targeting behaviors of CIN at a molecular level., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Ultraviolet (UV) irradiation generates reactive oxygen species (ROS) in the cells, which induces the cellular senescence and photoaging. The present study investigated the protective effects of garlic on photo-damage and cellular senescence in UVB-exposed human keratinocytes, HaCaT cells. An in vitro cell free system was used to examine the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals and nitric oxide (NO). The effect of garlic extract on ROS formation, MMP-1 protein and mRNA expressions, cytokines such as interleukin (IL)-1β and IL-6, senescence associated-β-galactosidase (SA-β-gal) activity, and silent information regulator T1 (SIRT1) activity were determined in UVB-irradiated HaCaT cells. Garlic exhibited strong DPPH radical and NO scavenging activity in cell free system exhibiting IC50 values of 2.50 mg/mL and 4.38 mg/mL, respectively. Garlic pretreatment attenuated the production of UVB-induced intracellular ROS. MMP-1 level, which has been known to be induced by ROS, was dramatically elevated by UVB irradiation, and UVB-induced MMP-1 mRNA and protein expressions were significantly reduced by garlic treatment (50 µg/mL) comparable to those of UV-unexposed control cells. UV-induced pro-inflammatory cytokine productions (IL-6 and IL-1β) were significantly inhibited by pretreatment with garlic in a dose-dependent manner. SA-β-gal activity, a classical biomarker of cellular senescence, and SIRT1 activity, which has attracted attention as an anti-aging factor in recent years, were ameliorated by garlic treatment in UV-irradiated HaCaT cells. The present study provides the first evidence of garlic inhibiting UVB-induced photoaging as a result of augmentation of cellular senescence in HaCaT human keratinocytes.

From an easily available partially protected analog of 1-deoxy-L-gulo-nojirimycin, by chain-branching at C-4 and suitable modification, lipophilic analogs of the powerful β-D-galactosidase inhibitor 4-epi-isofagomine have been prepared. New compounds exhibit considerably improved inhibitory activities when compared with the unsubstituted parent compound and may serve as leads toward new pharmacological chaperones for GM1-gangliosidosis and Morquio B disease., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The first total synthesis of (+)-broussonetine W (4), a naturally-occurring pyrrolidine iminosugar isolated from the traditional Chinese medical plant Broussonetia kazinoki SIEB (Moraceae), has been completed through a concise synthetic route starting from the readily available d-arabinose derived cyclic nitrone 10 in 11 steps and 31% overall yield, with regioselective installation of the α,β-unsaturated ketone functional group by the elimination of HBr from α-bromoketone as the key step. A number of analogs of (+)-broussonetine W (4) with variable side chain length, different polyhydroxylated pyrrolidine core configurations or saturated cyclohexanones have also been prepared to explore the glycosidase inhibition and the preliminary structure-activity relationship of this intriguing class of compounds. Glycosidase inhibition studies identified the natural product (+)-broussonetine W (4) as a selective and potent inhibitor of β-galactosidase (IC50 = 0.03 μM), while its enantiomer was a selective and potent inhibitor of α-glucosidase (IC50 = 0.047 μM). It was found that the configuration of the polyhydroxylated pyrrolidine ring played a key role on their glycosidase inhibitory activities. The length of side chain and α,β-unsaturated ketone functional group also exhibited some effect on their glycosidase inhibition.

Cancer is one of the primary causes of death worldwide. A high-precision analysis of biomolecular behaviors in cancer cells at the single-cell level and more effective cancer therapies are urgently required. Here, we describe the development of a magnetically- and near infrared light-triggered optical control method, based on nanorobotics, for the analyses of cellular functions. A new type of nanotransporters, composed of magnetic iron nanoparticles, carbon nanohorns, and liposomes, was synthesized for the spatiotemporal control of cellular functions in cells and mice. Our technology will help to create a new state-of-the-art tool for the comprehensive analysis of "real" biological molecular information at the single-cell level, and it may also help in the development of innovative cancer therapies., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Long-chain proline-rich antimicrobial peptides such as bumblebee abaecin show minimal activity against Gram-negative bacteria despite binding efficiently to specific intracellular targets. We recently reported that bumblebee abaecin interacts with Escherichia coli DnaK but shows negligible antibacterial activity unless it is combined with sublethal doses of the pore-forming peptide hymenoptaecin. These two bumblebee peptides are co-expressed in vivo in response to a bacterial challenge. Here we investigated whether abaecin interacts similarly with pore-forming peptides from other organisms by replacing hymenoptaecin with sublethal concentrations of cecropin A (0.3 μM) or stomoxyn (0.05 μM). We found that abaecin increased the membrane permeabilization effects of both peptides, confirming that it can reduce the minimal inhibitory concentrations of pore-forming peptides from other species. We also used atomic force microscopy to show that 20 μM abaecin combined with sublethal concentrations of cecropin A or stomoxyn causes profound structural changes to the bacterial cell surface. Our data indicate that the potentiating functional interaction between abaecin and pore-forming peptides is not restricted to specific co-expressed peptides from the same species but is likely to be a general mechanism. Combination therapies based on diverse insect-derived peptides could therefore be used to tackle bacteria that are recalcitrant to current antibiotics., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

From an easily available partially protected formal derivative of 1-deoxymannojirimycin, by hydroxymethyl chain-branching and further elaboration, lipophilic analogs of the powerful β-d-galactosidase inhibitor 4-epi-isofagomine have become available. New compounds exhibit improved inhibitory activities comparable to benchmark compound NOEV (N-octyl-epi-valienamine) and may serve as leads towards improved and more selective pharmacological chaperones for GM1-gangliosidosis., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Several galactonoamidines were previously identified as very potent competitive inhibitors that exhibit stabilizing hydrophobic interactions of the aglycon in the active site of β-galactosidase (Aspergillus oryzae). To elucidate the contributions of the glycon to the overall inhibition ability of the compounds, three glyconoamidine derivatives with alteration in the glycon at C-2 and C-4 were synthesized and evaluated herein. All amidines are competitive inhibitors of β-galactosidase (Escherichia coli) and show significantly reduced inhibition ability when compared to the parent. The results highlight strong hydrogen-bonding interactions between the hydroxyl group at C-2 of the amidine glycon and the active site of the enzyme. Slightly weaker H-bonds are promoted through the hydroxyl group at C-4. The inhibition constants were determined to be picomolar for the parent galactonoamidine, and nanomolar for the designed derivatives rendering all glyconoamidines very potent inhibitors of glycosidases albeit the derivatized amidines show up to 700-fold lower inhibition activity than the parent., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

A series of conformationally locked C-glycosides based on the 3-aminopyrano[3,2-b]pyrrol-2(1H)-one (APP) scaffold has been synthesized. The key step involved a totally stereocontrolled C-Michael addition of a serine-equivalent C-nucleophile to tri-O-benzyl-2-nitro-D-galactal, previously published by the authors. Stereoselective transformations of the Michael adduct allowed us the synthesis of compounds with mono- or diantennated aglycone moieties and different topologies. In vitro screening showed highly selective inhibition of bovine liver β-glucosidase/β-galactosidase and specific inhibition of human β-glucocerebrosidase among lysosomal glycosidases for compounds bearing palmitoyl chains in the aglycone, with a marked dependence of the inhibition potency upon their number and location. Molecular dynamics simulations highlighted the paramount importance of an optimal orientation of the hydrophobic substituent to warrant efficient non-glycone interactions, which are critical for the binding affinity. The results provide a rationale for the strong decrease of the inhibition potency of APP compounds on going from neutral to acidic pH. The best candidate was found to behave as pharmacological chaperone in Gaucher fibroblasts with homozygous N370S and F213I mutations, with enzyme activity enhancements similar to those encountered for the reference compound Ambroxol.

Hericium erinaceum is an edible and medicinal mushroom widely used in Korea, Japan, and China. On the search for biologically active compounds supporting the medicinal usage, the MeOH extract of the fruiting bodies of H. erinaceum was investigated for its chemical constituents. Six compounds were isolated and identified as hericenone D (1), (22E,24R)-5α,8α-epidioxyergosta-6,22-dien-3β-ol (2), erinacerin B (3), hericenone E (4), hericenone F (5) and isohericerin (6) by comparing their spectroscopic data with previously reported values. The inhibitory effects on adriamycin-induced cellular senescence in human dermal fibroblasts (HDFs) and human umbilical vein endothelial cells (HUVECs) of the isolates (1-6) were studied. Among the isolated compounds, ergosterol peroxide (2) reduced senescence associated β-galactosidase (SA-β-gal) activity increased in HUVECs treated with adriamycin. According to experimental data obtained, the active compound may inspire the development of a new pharmacologically useful substance to be used in the treatment and prevention of age-related diseases.

Enzyme inhibitors are ubiquitous in all living systems, and their biological inhibitory activity is strongly dependent on their molecular shape. Here, we show that small zinc oxide nanoparticles (ZnO NPs)-pyramids, plates, and spheres-possess the ability to inhibit activity of a typical enzyme β-galactosidase (GAL) in a biomimetic fashion. Enzyme inhibition by ZnO NPs is reversible and follows classical Michaelis-Menten kinetics with parameters strongly dependent on their geometry. Diverse spectroscopic, biochemical, and computational experimental data indicate that association of GAL with specific ZnO NP geometries interferes with conformational reorganization of the enzyme necessary for its catalytic activity. The strongest inhibition was observed for ZnO nanopyramids and compares favorably to that of the best natural GAL inhibitors while being resistant to proteases. Besides the fundamental significance of this biomimetic function of anisotropic NPs, their capacity to serve as degradation-resistant enzyme inhibitors is technologically attractive and is substantiated by strong shape-specific antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), endemic for most hospitals in the world.

Scavenger receptor A (SRA) has been implicated in the processes of tumor invasion and acts as an immunosuppressor during therapeutic cancer vaccination. Pharmacological inhibition of SRA function thus holds a great potential to improve treatment outcome of cancer therapy. Macromolecular natural product sennoside B was recently shown to block SRA function. Here we report the identification and characterization of a small molecule SRA inhibitor rhein. Rhein, a deconstructed analog of sennoside B, reversed the suppressive activity of SRA in dendritic cell-primed T cell activation, indicated by transcription activation of il2 gene and production of IL-2. Rhein also inhibited SRA ligand polyinosinic:polycytidylic acid (poly(I:C)) induced activation of transcriptional factors, including interferon regulatory factor 3 (IRF3) and signal transducer and activator of transcription 1 (STAT1). Additionally, this newly identified lead compound was docked into the homology models of the SRA cysteine rich domain to gain insights into its interaction with the receptor. It was then found that rhein can favorably interact with SRA cysteine rich domain. Collectively, rhein, being the first identified small molecule inhibitors for SRA, warrants further structure-activity relationship studies, which may lead to development of novel pharmacological intervention for cancer therapy., (Published by Elsevier Ltd.)

A series of eight stereoisomeric N-(tetrahydroxy bicyclo-[5.1.0]oct-2S*-yl)phthalimides were prepared in one to four steps from N-(bicyclo[5.1.0]octa-3,5-dien-2-yl)phthalimide (±)-7, which is readily available from cyclooctatetraene (62 % yield). The structural assignments of the stereoisomers were established by (1) H NMR spectral data as well as X-ray crystal structures for certain members. The outcomes of several epoxydiol hydrolyses, particularly ring contraction and enlargement, are of note. The isomeric phthalimides as well as the free amines did not exhibit β-glucosidase inhibitory activity at a concentration of less than 100 μM., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A new type of galactose mimetics has been synthesized following a straightforward synthetic approach based on cyclohexene olefin aziridination reactions directed by hydroxyl substituents. These enantiomerically pure galacto-configured N-aminoaziridines are potent irreversible inhibitors of Aspergillus oryzae and Escherichia coliβ-galactosidases.